Says short video, keeps it a little under 14 minutes. Says he's not doing an tutorial channel and manages to be a top resource to go to. Pure gold! You can almost get 20 years worth of EE experience just by listening to Dave going into all the little minutia. You can actually get a "feel" for this stuff and feel confident enough to do build your own charging circuit just by watching this video.
Making use of the czcams.com/users/postUgkxcJ22tnHH9l1vjdIdEIG27iOG55P7LXI8 reconditioning plan, I just saved 2 auto batteries from being completely junked. The guides were very simple to follow. I wish I would have found this years ago! You may use the guide to recondition any battery type
Sorry for the re-uploads, I wanted to remove most of the the voltage drop stuff to avoid confusion and constant emails and messages and comments for the next 5 years.
+Fermioncool Fermioncool I assume the voltage drop could be seen as a extra security, at the batteries emd you will never go beyond 4.2, again I assume.
Dave, maybe this is a small video, but the topic is very popular in recent times, and every mistake can be noticed and stigmatized that it is not repeated.
I have been charging 18650 cells on my lab supply for years. Set the current to 1A and the voltage to 4.2v per cell. Stop charging once the current is reduced to 100mA. Sometimes I charge overnight with a current limit of 250mA and again stop the charge when the current reaches 100mA. I have started experimenting with TP4056 modules which automatically stop the charge which is quite handy for unattended charging.
Rigol actually has an app note, warning you not to hook up batteries, without at least a diode as protection, since the DP832's inputs are apparently very sensitive to being fed with voltage or current.
I liked how you repeated certain parts of the video Dave. Like when discussing the graph. This is really really helpful for people like me who struggle to learn these ideas.
You could put your power supply on a cheap outlet shut-off timer if you didn't have a fancy expensive power supply. 3:20 I'm commenting on that 3.5-inch digital multimeter again. Watch out for that first step, it's a doozy.
Nice video. I've got a Rigol DP832, no doubt because you've shown/reviewed/talked about it here. A video showing how to use some of the advanced features would be useful to me! Many of these devices are similar....the concepts would transfer to other makes and models...
The safe max charging V for that Panasonic cell = 4.25V The recommended charge cut-off A = 65mA (which is 0.02C, not 10% of the CC). Thanks for sharing. p.s.: If you want to get max cycle life out of the cell, it is recommended to charge it to a max V of 4.1V & not discharge it more than 20% when using it. >= 50% DOD really creates a significantly shortened cell life.
OrbitalSP2: Well, your power needs may be quite different than someone who wants optimal cell life--which is fine--you'll just consume more cells & pay more $ for your power needs than a person seeks optimal cell life.
A B I know what you say is true. But i just avoid discharging more than 80%. I mean discharging only 20% only, I can't even see in what aplication that might be useful. 20 minutes runtime in a flashlight?
+OrbitalSP2 A flashlight that isn't used much or often is a perfect example. I have a high power flashlight that I use occasionally around the house & I rarely use it for longer than 5 minutes in a day. A remote control that is placed on a wireless charging mat when not in use would be another good example.
A B they degrade with time, even by doing nothing with them. So I'd rather use them from 20 to 90% or 20 to 100%. Unless you live in a very very cold country, the ambient temperature is killing them anyways...
Nice video! Thanks!! Any chance you could do a follow up or give a base explanation of how to charge a Lithium ion pack with cells in series and parallel?
I remember when Chris Boden of The Geekgroup kicked me out of their IRC for explaining how you do this. According to him it's insanely dangerous and should never be done. He seriously knows fuck all about a lot.
Why it is dangerous? This is Li ion not LiPO battery. So the explosive is not in the equation. Also Li Ion already has built in BMS or PCB nowadays to protect battery from overvoltage or undervoltage. Any specific information about how do you kick from IRC? He should explain why it is dangerous and the explanation behind it.
You ask him.. He apparently knows more than anybody else in this world. He's also the guy who claimed that Corning optical USB cables don't work because "USB is a fussy bitch" ? Fake it till you make it..
These cylindrical li-on cells are safe, even these without afterparty protection circuits, because cell has inside safety pressure valve, fuse, and CID button(opens circuit when overheated). But if you will smash positive side(where all these protections are) battery may turn into flamethrowner or even explode if overloaded, overheated or overcharged.
USB is indeed a fussy bitch! Implementing an interrupt or iso endpoint by hand in USB 1.1 and 2.0 gives me massive shivers. But something interesting happened. Earlier USB protocols were limited by cable length because of latency issues. USB 3.0 apparently has ways of working around that. Also i have a slight hunch of how some re-synchronization could be implemented for earlier protocols to offset latency of signal-converting electronics. But it would take a person a million times better than me to actually accomplish that. But who is this Chris Boden person anyway? Never heard of them.
Electricguy Well, as long as you know what you're doing (and disconnect the battery at or near the cutoff current), it's fine. I'm not sure if I'd want complete amateurs attempt something like this though....
FUCK OFF! .... in a ten minute video they CONTRDICTED THEMSELVES SEVERAL TIMES. Boost converter is ALREADY EXISTENT IN MOST (>90%) DEVICES THAT COST MORE THAN 10$. Also their claims are unfounded SINCE THE POWER CAPABILITIES OF ALKALINE BATTERIES DETERIORATE. EVEN IF YOU INCREASE THE VOLTAGE THE CURRENT WON'T BE ENOUGH due to rapid increase of internal resistance after 1.25 V. Anything more powerful than 2 Watts cannot benefit from a boost converter after that voltage. Claims that typical alkaline batteries use about 20% of their available energy ARE PURE BULLSHIT. BATTERISER, if it works optimally and does squeeze every last drop out of alkaline batteries (and does so safely), is probably going to increase typical battery life by about 20%, not 800% HERE IS THE MINIMAL VOLTAGES THAT COMMON CHEAP DEVICES REQUIRE: autofocus camera with flash: 1.3v halogen flashlight: 1.3v regular flashlight: 1.2v headphone/CD player: 1.2v portable LCD TV: 1.2v pencil sharpener: 1.2v AM/FM radio: 1.0v electric shaver: 1.0v quartz clock: 1.0v remote control: 0.8v Microsoft cordless optical mice have a cutoff voltage of 0.6v, and Logitech mice of 0.8v ALL YOU NEED TO DO IS SWAP THE BATTERIES TO A DEVICE THAT CAN USE THE REST OF THE AVAILABLE CAPACITY
I did read that Lipo batteries are more dangerous to charge without a specific "balancing" charger . Then may be some balancing circuitry exists in my battery pack, not only a heat sensor and constant current constant voltage circuitry (?) I did unsold it from the batteries to be sure of what happens) thank you
If you use a low charging current, you can get away with a very simple circuit. I have a 5v solar cell that puts out 300 ma at 3.5 volts, down to 25mA or so at 4.2 volts. I determined the current values empirically for my setup (expected illumination conditions) before proceeding. Works perfectly on this kind of cell, it just takes a day or so. I can leave the cell connected indefinitely with this setup. Works great if you're not in a hurry for that charge. I use a number of cells that I cycle through.
Well - as long as you 5V solar cell really never goes above 4.2 V that is. getting the cell to 4.3 v a single time might already destroy it completely.
ABaumstumpf Its a new setup, about 10 days old now. The solar cell only puts out a trickle of current maybe one hour a day, when the battery is full. I will be watching it closely for a while. You are right in that it is an iffy setup. A bit of an experiment, which, so far, appears to be working.
I use a similar set-up, but I always use either protected cells or cells to which I've added a protection circuit. That ensures that once the cell has received a full charge, it won't over-charge and also once it discharges too low, the output will cut off.
The thing today is reviving a dead battery back. Personally to me the method used by many is to zap the pack, with a like good battery by connecting the packs in parallel for seconds, is haphazard. While it is politically not proper for the consumer to rejuvenate a pack, having to scrap a pricey pack within months of purchase is a waste. The pack I rejuvenated is a 18v, 36AH Hoover Links vacuum cleaner. It consists of 5 18650 cells in series and with a large circuit board. Each cell measured 0.14v except one, that one cell was 0.010v. This cell I charged at 15mA with the supply set at CC. The corresponding voltage was 0.5v and CV set to the same. Once the supply switched from CC to CV, I gradually, increments, set the CV higher while keeping the CC the same. Initially the supply took about an hour to switch from CC to CV, this change caused the current of 15mA to go 0.0mA. Eventually ended the charge on each cell at 4.0v with CC at 200mA, once the cell voltage reached 4.0v the charge current will drop to 0mA. The pack appears to work OK now but unknown as to life compared to non rejuvenated pack. The battery packs appear to run at high drain because the vacuum only runs for 15 minutes when the motor goes noticeably slower and the power low battery indicator flashes. I suggested to the users of the vacuum to stop using when the indicator flashes/or sound of motor becomes weak. Do not run until it dies.
cant remember where but somewhere I read a while back that if they drop below 2.5v for any real length of time (a few months+) a chemical reaction takes place that can cause sudden internal partial/total shorts and possible fire/severe heat and venting, hence why the protection circuit will not allow you to charge a cell if it drops below about 2.5v. You can usually tell if a cell has a problem as it gets warm as you charge it... and a very good reason not to use unprotected cells...
That is an old wives tall (I have charged a battery that was at 1.4V for a few years without it heating up or swelling), the main damage comes from when the cell voltage is reversed.
Tyvm for good a explanation. I don't know anything about electronics but i recently did this a couple of times with a homebuilt powersupply/lab. I only charged it for short periods tho and monitoring it while doing so but it feels a bit sketchy when not having the knowledge :D My battery was 500mah and i charged it at 0.5a tho but now i know to lower that! My voltage setting was not set by specs, more based on some quick basic values i found online that semt to correlate somewhat to the battery type. I did have in consideration that the battery could go poof while trying this.
Hey Dave, can you do a video on how to “revive” a flat lipo pack? I see other CZcams videos from others but it would be good to get your explanation on how or why this works.
Thanks for uploading this. This made me finally charge my Canon camera LP-E6 battery with a constant current on 650mA and when reaching the maximum voltage of 8.4v i changed over to constant voltage and see exactly the same where the current starts dropping! Wow, i really need the camera tomorrow and you made me do it! Best youtuber EU! (i know you're not in the EU)
I was thinking if you calculated the right resistor, you could rig a transistor in there so that once the current goes too low (the cut-off point), the transistor breaks the connection to the battery.
3.25V is not always a dead battery, that depends on the specific cell. I have cells that won`t die untill around 2.5V resting voltage.. (18650 high drain cells, both my sony`s and samsungs can live at 2.5 and 2.75V respectively, as long as they don`t SIT at that voltage over any period of time. I regularly have them down to 3.4..)
Hi, actually using lab power supply can be little bit tricky - if your power supply can also sink current (like mine does) it could easily damage your battery - in case of (even brief) AC power failure the power supply defaults to 0V/0A and sinks current from the battery down to 0V and destroying it. Yes, I can program it to default to 4.2V/0.01A but this can be dangerous if you forget about it and work on something sensitive afterwards. For charging liion cells I use simple boards from ebaywith IC TP4056. I bought like 5 of them for $2. Input is 5V from USB and output 1A (lower currents configurable by changing single resistor). It also properly terminates around 10% of set current.
Out of everything on my bench the Rigol DP832 power supply is the most sensitive to power surge and flickers. I've seen it reboot were the scope and bench DMM stayed up. My house has a lot of power flickers, constantly resetting clocks, DVR not recording the whole show. That's why I run UPC APC 1500VA backups at my bench and entertainments system. I use a laptop to collect data from my equipment so it stays running on its own battery, but nothing worse then trying to trend something over 24 hours and see temperature change effect and have a power flicker screw up all the data and have to start over.
@@EEVblog Hi Dave, my supply wont operate in CC mode with a series diode. Will utilizing the remote sensing feature of my Kikusui PMC 18-5A solve this issue?
I'm about to buy my first power supply. I will be charging the occasional cell with it and powering amplifiers and small circuits. Should I be looking for Linear or Switching?
WARNING: With Channel 1 OFF. I connected a 26V Lithium battery pack to channel 1 of the DP832 and it damaged the PSU. In Daves words "Magic smoke time". With the channel off the PSU can sink current from a connected battery and this blows something in the power supply. Over current protection was on, so probably that. In contrast, just the day before I had been charging 12V Lithium batteries with no problems at all. Afterwards the display gave the error message “Charge overcurrent protection. Disable the output of CH1”. Now Channel 1 doesn't supply any power but luckily the rest are working. After some more research I found this Rigol doc on the Batronix website about not connecting active loads www.batronix.com/files/Rigol/Labornetzteile/DP8_DP1_ActiveLoads.pdf. Apparently with the DP800 and DP1000 the channel output is not turned on with a relay so the over current protection / control circuitry is still active even with the channel off. They recommend using a protection diode in series with the battery to charge. The main manual has this, which I don't fully understand and says it can damage the powered device not the Power supply. Do Not Provide Power for the Active Load. In order to avoid the anti-irrigation current which leads to the power control loop out of control and damages the powered device, this power supply can only provide power for the pure load without the current output function.
Hey would you do a strip down of any "vaporizer" regulated battery modules? They generally use 18650 batteries to heat a coil which vaporises liquid. I think it's interesting from an EE perspective because these mods measure the resistance of the coil, and use some kind voltage stepper to allow you to select a wattage for powering the coil.
I bought this same power supply because Adafruit suggested it. I'm glad to see someone else using it. I love my power supply, and yes I do remember when Dave bought this with the upgraded software. It's still nice to see someone else using it. Can someone quickly tell me how to set the low current cut off that he didn't want to show in the video?
I'd love to get that supply, but it's way too rich for my blood. I have the $50 ebay special,which also can do this but it's a lot more of a bugger to set exact values on.
as far as i can tell, he was talking about setting a cutoff timer after x hours. I don't have the supply myself, but there's a timer button visible on the front- maybe that can help. Or just read the manual :)
I have experimented with using python via telnet and VBA (in excel) via VISA to DP831 to status and control. Works very well. DP831 (DP832 would be almost the same to control) is very open and relatively straightforward to control via ethernet. Suspect USB would also be an option. Python would be my first option for battery charge control. Could also add safety shutdowns by monitor for weird battery behaviour like increasing current over time and OFF the output. There was some clever front panel tricks hinted at in the manual that may help with with battery charging but I glossed over these as I figured programmatically would be the most flexible fastest approach for me.
My electric drill/flashlight battery charger charges to 4.0V, so that's like 3 times more longevity or even better. Great for the environment for sure. I also charge my phone up to 75% for the same reason (only possible if rooted).
There is a warning about charging batteries with a DP832 because it isn't designed to handle voltage sources on its output. The supply can't work in second or fourth quadrant (meaning it will become unstable if an external voltage tries to discharge through the supply). Wasn't this on another one of your videos reviewing this supply? Thanks to Róbert Valdimarsson for posting this warning from Rigol about connecting batteries to the DP832 output: www.batronix.com/pdf/Rigol/DP8_DP1_ActiveLoads.pdf Be very careful not to allow the PSU voltage to be set below the battery voltage.P.S. Why the hell does IE wreck the formatting of a comment whenever you try to edit it?
I do recall similar warning from another forum re other PSU. Quote "You want to be very very careful hanging large batteries across power supplies. Astron has a 723 based design, which has a crowbar on the supply output. The intention is that the crowbar will prevent equipment damage if the pass transistors short or the regulator goes high. What happens with batteries on the output is that it also shorts the batteries, and may cause a fire. Always put a fuse between PS output and the battery!."
Its cool but the smart chargers for these are incredibly cheap on ebay/aliexpress these days, the days of the 80 dollar smart chargers is over. I use a liitokala, also measures capacity with a charge/drain test.
I have a confusion.. While you say the charging current should be 1/2c.. so for a 3400mah , it is set at 1700ma But what about when charging a power Bank made out of say 2 of these.. What should be the charging current then.. And, if the constant current is set at lower than 1/2c, i understand it will take longer to charge, but does it have any effect on its life span? Also, at some point you said that the constant voltage phase reduces life cycle..so does that mean we should omit it ? At what percentage of battery capacity does that constant voltage phase usually start? So is there a range in which there is a maximum life span? Is it the recommended 20-90 percent?
Hi Dave, could you please comment on the document from Rigol "Active loads and the RIGOL DP800 and DP1000 Series". It says "an external diode should be used to prevent the flow of current into the supply and prevent damage of the power supply".
thank you for talking about slowly rising voltage when in constant current mode but i saw something when i charge the battery with constant current mode . the voltage drop across battery was 4.2 v or around that. and voltage across the cell before charging was around 3,8 . so why is it behave like this. isnt it should be 3,8 v across the cell while charging it with constant current and slowly rise the voltage naturally like you show in the video ?
Have done this with one battery no problem, but if I do the same with 8 batteries in parallel, I still only get the same current as if I would charge one battery. So it will take 8 times longer to charge them together rather then one at the time. Why is that? It doesn't make sense.
"you don't want to actually uh trickle charge or float charge lithium-ion batteries like this because it can actually uh build up or plate the uh lithium inside the metallic lithium inside the battery and yeah you don't want to do that they're not designed for that there are um there are chipsets designed for float charging and they use like a pulse uh a slow pulse" -- Is the same true of the trickle charge for a dead cell?
On the topic of the charging voltage being 4.20V +/- 1%: Couldn't I just play it safe and not exceed, say 4.1V? I would sacrifice some capacity, but that should be enough to get the battery quite near its nominal capacity, give me plenty of tolerance for my power supply and mitigate the overcharging issue.
If you do that you will even increase the number of charging cycles before the battery capacity falls down considerably. The only penalty is lower charged capacity (when charging to 4.1V instead of 4.2V), but not much cca. 15% lower. Source: batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
I do not want to advertise , but for those interested in a universal charger with good value for money I suggest you use imax v2 B6AC I bought to recycle many 18650 retrieved from the laptop battery packs . Many 18650 batteries such as Sanyo or lg , reach their maximum capacity if charged at 4.30 volts as the data sheet says .
Great video bro, but at the beginning of the video you tell that you don't know the cut-off current, albeit it is written clearly on the datasheet and you will reference it later.
No. Always keeping a li-ion cell at or near its maximum voltage can greatly reduce its life span. For long term storage, they should be at about 3.6v. If you are going to charge it up, use it
The bottom and top 20% of li-ion capacity should not be used, as it destroys the batteries prematurely. At the expense of losing Wh/kg (and thereby Wh/$), you can increase the meaningful lifespan of any li-ion battery. This is what is done in electric cars, where longevity is actually expected (unlike a laptop, where people sort of expect the battery to be complete shit in 2 years time)
"The cut off point is 175mA for example, it doesn't show that here" Nobody reads the datasheets for the data am I right? :) _Charge: CC-CV 0.5C (max) 4.20 (Blaze it), _*_65mA cut-off_*_ at 25 Celsius_
Think you should have mentioned why the cells cannot be charged in series (@8.4 - 12.6 etc). Also i thought a single was a "Cell" and more than 1 "Cell" is a Battery (which makes this a cell) ? Good work though.
Why some people say that this can damage the power supply cause the battery will try to "charge" the power supply after the charging is done? They suggest using a diode and then it can be done.
LiPo Batteries? Never heard of that abbreviation. So I guess you can call completely discharging a LiPo battery a LiPoSucktion? :) Great video btw. I always thought you needed complex electronics to monitor the temperature and internal resistanance very accurately or otherwise your battery would explode on overcharging or completely brick it when discharged below a certain level. But I have to stand corrected.
You can do the same, with different voltages and currents for NiCd, NiMh batteries. I've been recharging 1.5V _alkaline_ cells as well with my PSU, works great (1.7V, 150mA). Doesn't work on 9V batteries, though. :(
Since cells vary, how do "smart chargers" determine the proper rate for different cells? Are they all similar enough that they can just use a conservative value?
That's pretty much the case. If you're sure you'll always be charging an 18650, you can use a low charge current such as 500mA and most of the time that will be fine since nearly all batteries of that size are at least 2000mAh in size, except for those cheap Chinese rip-offs. The charging current could be too high for some of those. On the other hand, some of the tiny flat cells can be as low as 150mAh, so you'd need a charger which goes as low as 75mA to safely charge those. It would take ages to charge an 18650 at that current, so there's no such thing as a truly universal lithium charger with a fixed charging current. "Smart" chargers generally either assume you'll be only charging a certain physical size of battery or rely on you to set the charge current.
Nice video! How about batteries with multiple cells in series? Is there a way to guarantee they are balanced using a power supply given the batteries have that additional connector they come with?
I didn't hear you mention the 'precharge' part of the cycle... If the cell voltage is below a critical value (usually around 3.2 volts) it's supposed to be bad to whack lots of current in at first... datasheets I've read say to trickle it up to nominal voltage, and _then_ go to the main constant current charge mode. I'm not sure of the exact chemistry reason, (may be a LiPo thing more than LiIon) but the feature's built into charger chips at a hardware level, so it's probably important. Not usually an issue unless you run batteries flat and then forget about them for months. But isn't that what happened here?
1 what is the red line on the graph in the data sheet 2 when you go to constant voltage, how, why does the current drop. Its pretty clear what happens in the constant current phase, but then what is the magic
A question. Say that you wanted to charge a battery while it's in use. Similar to how a laptop charges it's battery with the power on. I take it that all you would need is a battery charger in parallel with the battery that is capable of putting out enough current both to power the device as well as top up the battery. Since the charger would limit voltage to 4.2 and reduce amperage as the battery charges, this should work right? I want to convert a remote control vehicle to be able to self charge with a dock and always be on, for a security robot.
The battery specs seem to be really conservitive on the charge rate, 0.5c . 4 hours though seems really long for charging at 0.5c though. at 1 c the charge time should be around 1 hour. Though maybe these cells have much higher internal resistance than higher performance batteries. My RC helis can charge safely at 2c which takes about 40 minutes. But those batteries can be discharged at 35c so internal resistance is fairly low. As an added safety note, lipo batteries should not be left charging unattended. Just checkout rcgroups thread lipi fires are real!! for plenty of stories about lipo fires. with higher capacity batteries the fires can start very fast and grow large in short periods of time. Very large batteries will burn furiously for over 30 minutes on its own without any other combustable materials nearby.
I have some questions. When at the phase of Constant current. Your lab power supply will force the current deliver to always stay at 1.7 A, right ? While the voltage from your PSU does not matter as long as does not pass 4.2V limit. And when the the voltage is at 4.2, your lab power supply will maintain the voltage at 4.2 from your PSU and let the current sinking?
I'm a bit confused.. Why does it say 3.7V on the battery but we charge it to 4.2V? ...Even the datasheet says to charge it at 4.2V but the "nominal voltage" of the battery is 3.6/3.7V
Have you played with some MPPT solar charge controllers? I'm wondering if there is one useful solar charge controller that can charge a pack of 18650 equipped with a BMS? The only one that I could find and can be programmed via their software on a PC is ProStar MPPT from MorningStar and it's like $480, Some other manufacturers charge a $150 fees on top for factory programing.
Thanks nice tutorial. Few questions, 1.In cc mode if voltage supply exceeds 4.2 v does it damage battery before it reaches cv mode? 2.Can u plz explain how ev dc fast charging works? 3. Also how charging efficiency is managed. Thanks a lot Dave.
Thank you for this and what you do. I'm still learning EE for personal projects. Instead of an egg timer, watch, or smartphone alarm. Wouldn't it be ok to just plug the power-supply into an outlet-timer?
Says short video, keeps it a little under 14 minutes. Says he's not doing an tutorial channel and manages to be a top resource to go to. Pure gold! You can almost get 20 years worth of EE experience just by listening to Dave going into all the little minutia. You can actually get a "feel" for this stuff and feel confident enough to do build your own charging circuit just by watching this video.
them gatekeepers
Making use of the czcams.com/users/postUgkxcJ22tnHH9l1vjdIdEIG27iOG55P7LXI8 reconditioning plan, I just saved 2 auto batteries from being completely junked. The guides were very simple to follow. I wish I would have found this years ago! You may use the guide to recondition any battery type
Sorry for the re-uploads, I wanted to remove most of the the voltage drop stuff to avoid confusion and constant emails and messages and comments for the next 5 years.
What was the problem?
🖒
And i thought youtube does not like your videos anymore ;-)
+Fermioncool Fermioncool I assume the voltage drop could be seen as a extra security, at the batteries emd you will never go beyond 4.2, again I assume.
Dave, maybe this is a small video, but the topic is very popular in recent times, and every mistake can be noticed and stigmatized that it is not repeated.
I have been charging 18650 cells on my lab supply for years. Set the current to 1A and the voltage to 4.2v per cell. Stop charging once the current is reduced to 100mA. Sometimes I charge overnight with a current limit of 250mA and again stop the charge when the current reaches 100mA. I have started experimenting with TP4056 modules which automatically stop the charge which is quite handy for unattended charging.
what aliexpress supply can do this stuff?
max is 1C
Thank you! I spent $400 on a drone, and didn't buy a lipo charger because I thought I had one. This will get me buy until Amazon gets one to me!
Rigol actually has an app note, warning you not to hook up batteries, without at least a diode as protection, since the DP832's inputs are apparently very sensitive to being fed with voltage or current.
Thanks, I was looking for that. I was sure Dave mentioned this in a previous video. He must have forgotten.
I liked how you repeated certain parts of the video Dave. Like when discussing the graph. This is really really helpful for people like me who struggle to learn these ideas.
You could put your power supply on a cheap outlet shut-off timer if you didn't have a fancy expensive power supply.
3:20 I'm commenting on that 3.5-inch digital multimeter again.
Watch out for that first step, it's a doozy.
Thanks for the idea, 100% gunna use that one
It's been mentioned, but military tech only charges lithium batteries to 3.9v. Maybe 80% of the capacity, but close to 5 times more charge cycles.
Yes, at a "storing" voltage... exactly right
Nice video. I've got a Rigol DP832, no doubt because you've shown/reviewed/talked about it here. A video showing how to use some of the advanced features would be useful to me! Many of these devices are similar....the concepts would transfer to other makes and models...
The safe max charging V for that Panasonic cell = 4.25V
The recommended charge cut-off A = 65mA (which is 0.02C, not 10% of the CC).
Thanks for sharing.
p.s.: If you want to get max cycle life out of the cell, it is recommended to charge it to a max V of 4.1V & not discharge it more than 20% when using it. >= 50% DOD really creates a significantly shortened cell life.
A B Buying a cell to discharge it no more than 20%....no thanks.
OrbitalSP2:
Well, your power needs may be quite different than someone who wants optimal cell life--which is fine--you'll just consume more cells & pay more $ for your power needs than a person seeks optimal cell life.
A B I know what you say is true. But i just avoid discharging more than 80%. I mean discharging only 20% only, I can't even see in what aplication that might be useful. 20 minutes runtime in a flashlight?
+OrbitalSP2
A flashlight that isn't used much or often is a perfect example. I have a high power flashlight that I use occasionally around the house & I rarely use it for longer than 5 minutes in a day.
A remote control that is placed on a wireless charging mat when not in use would be another good example.
A B they degrade with time, even by doing nothing with them. So I'd rather use them from 20 to 90% or 20 to 100%. Unless you live in a very very cold country, the ambient temperature is killing them anyways...
Nice video! Thanks!!
Any chance you could do a follow up or give a base explanation of how to charge a Lithium ion pack with cells in series and parallel?
Also do a how to safely discharge video please, cheers !
I remember when Chris Boden of The Geekgroup kicked me out of their IRC for explaining how you do this. According to him it's insanely dangerous and should never be done. He seriously knows fuck all about a lot.
Why it is dangerous? This is Li ion not LiPO battery. So the explosive is not in the equation. Also Li Ion already has built in BMS or PCB nowadays to protect battery from overvoltage or undervoltage.
Any specific information about how do you kick from IRC? He should explain why it is dangerous and the explanation behind it.
You ask him.. He apparently knows more than anybody else in this world. He's also the guy who claimed that Corning optical USB cables don't work because "USB is a fussy bitch" ? Fake it till you make it..
These cylindrical li-on cells are safe, even these without afterparty protection circuits, because cell has inside safety pressure valve, fuse, and CID button(opens circuit when overheated).
But if you will smash positive side(where all these protections are) battery may turn into flamethrowner or even explode if overloaded, overheated or overcharged.
USB is indeed a fussy bitch! Implementing an interrupt or iso endpoint by hand in USB 1.1 and 2.0 gives me massive shivers.
But something interesting happened. Earlier USB protocols were limited by cable length because of latency issues. USB 3.0 apparently has ways of working around that.
Also i have a slight hunch of how some re-synchronization could be implemented for earlier protocols to offset latency of signal-converting electronics. But it would take a person a million times better than me to actually accomplish that.
But who is this Chris Boden person anyway? Never heard of them.
Electricguy Well, as long as you know what you're doing (and disconnect the battery at or near the cutoff current), it's fine. I'm not sure if I'd want complete amateurs attempt something like this though....
Wanna hear a joke?
Batteriser.
Lab power supplies aren't the same as batteries. Batteriser proved it!
FUCK OFF! .... in a ten minute video they CONTRDICTED THEMSELVES SEVERAL TIMES. Boost converter is ALREADY EXISTENT IN MOST (>90%) DEVICES THAT COST MORE THAN 10$. Also their claims are unfounded SINCE THE POWER CAPABILITIES OF ALKALINE BATTERIES DETERIORATE. EVEN IF YOU INCREASE THE VOLTAGE THE CURRENT WON'T BE ENOUGH due to rapid increase of internal resistance after 1.25 V. Anything more powerful than 2 Watts cannot benefit from a boost converter after that voltage. Claims that typical alkaline batteries use about 20% of their available energy ARE PURE BULLSHIT. BATTERISER, if it works optimally and does squeeze every last drop out of alkaline batteries (and does so safely), is probably going to increase typical battery life by about 20%, not 800%
HERE IS THE MINIMAL VOLTAGES THAT COMMON CHEAP DEVICES REQUIRE:
autofocus camera with flash: 1.3v
halogen flashlight: 1.3v
regular flashlight: 1.2v
headphone/CD player: 1.2v
portable LCD TV: 1.2v
pencil sharpener: 1.2v
AM/FM radio: 1.0v
electric shaver: 1.0v
quartz clock: 1.0v
remote control: 0.8v
Microsoft cordless optical mice have a cutoff voltage of 0.6v, and Logitech mice of 0.8v
ALL YOU NEED TO DO IS SWAP THE BATTERIES TO A DEVICE THAT CAN USE THE REST OF THE AVAILABLE CAPACITY
+Krasimir Ivanov Dude, it was a joke. Calm yourself.
I thought you were serious. WHEN IT COMES TO SNAKE OIL PHYSICS I NEED TRIGGER WARNINGS.
@Phil Weatherley You catch more flies with vinegar! I was pissed. LOL
I did read that Lipo batteries are more dangerous to charge without a specific "balancing" charger . Then may be some balancing circuitry exists in my battery pack, not only a heat sensor and constant current constant voltage circuitry (?) I did unsold it from the batteries to be sure of what happens) thank you
can I suggest a second video where you explain the problem of the original?
If you use a low charging current, you can get away with a very simple circuit. I have a 5v solar cell that puts out 300 ma at 3.5 volts, down to 25mA or so at 4.2 volts. I determined the current values empirically for my setup (expected illumination conditions) before proceeding. Works perfectly on this kind of cell, it just takes a day or so. I can leave the cell connected indefinitely with this setup. Works great if you're not in a hurry for that charge. I use a number of cells that I cycle through.
Well - as long as you 5V solar cell really never goes above 4.2 V that is.
getting the cell to 4.3 v a single time might already destroy it completely.
ABaumstumpf Its a new setup, about 10 days old now. The solar cell only puts out a trickle of current maybe one hour a day, when the battery is full. I will be watching it closely for a while. You are right in that it is an iffy setup. A bit of an experiment, which, so far, appears to be working.
I use a similar set-up, but I always use either protected cells or cells to which I've added a protection circuit. That ensures that once the cell has received a full charge, it won't over-charge and also once it discharges too low, the output will cut off.
It's so simple, but I've never thought about it! Thanks)
The thing today is reviving a dead battery back. Personally to me the method used by many is to zap the pack, with a like good battery by connecting the packs in parallel for seconds, is haphazard.
While it is politically not proper for the consumer to rejuvenate a pack, having to scrap a pricey pack within months of purchase is a waste.
The pack I rejuvenated is a 18v, 36AH Hoover Links vacuum cleaner. It consists of 5 18650 cells in series and with a large circuit board. Each cell measured 0.14v except one, that one cell was 0.010v. This cell I charged at 15mA with the supply set at CC. The corresponding voltage was 0.5v and CV set to the same. Once the supply switched from CC to CV, I gradually, increments, set the CV higher while keeping the CC the same. Initially the supply took about an hour to switch from CC to CV, this change caused the current of 15mA to go 0.0mA. Eventually ended the charge on each cell at 4.0v with CC at 200mA, once the cell voltage reached 4.0v the charge current will drop to 0mA.
The pack appears to work OK now but unknown as to life compared to non rejuvenated pack. The battery packs appear to run at high drain because the vacuum only runs for 15 minutes when the motor goes noticeably slower and the power low battery indicator flashes. I suggested to the users of the vacuum to stop using when the indicator flashes/or sound of motor becomes weak. Do not run until it dies.
you are missing a heavy schottky diode on the charge circuit (like a SR360) to protect the supply from reverse polarity on the Li battery.
cant remember where but somewhere I read a while back that if they drop below 2.5v for any real length of time (a few months+) a chemical reaction takes place that can cause sudden internal partial/total shorts and possible fire/severe heat and venting, hence why the protection circuit will not allow you to charge a cell if it drops below about 2.5v. You can usually tell if a cell has a problem as it gets warm as you charge it... and a very good reason not to use unprotected cells...
That is an old wives tall (I have charged a battery that was at 1.4V for a few years without it heating up or swelling), the main damage comes from when the cell voltage is reversed.
The capacity graph in the data sheet says it switches from cc to cv at about 80-90%, not 50%.
It can be quite chemistry/manufacturer dependent.
Actually, it should say when the charger should switch from CC to CV. not when the cell does.
Tyvm for good a explanation. I don't know anything about electronics but i recently did this a couple of times with a homebuilt powersupply/lab. I only charged it for short periods tho and monitoring it while doing so but it feels a bit sketchy when not having the knowledge :D My battery was 500mah and i charged it at 0.5a tho but now i know to lower that! My voltage setting was not set by specs, more based on some quick basic values i found online that semt to correlate somewhat to the battery type. I did have in consideration that the battery could go poof while trying this.
Hey Dave, can you do a video on how to “revive” a flat lipo pack? I see other CZcams videos from others but it would be good to get your explanation on how or why this works.
Thanks for uploading this. This made me finally charge my Canon camera LP-E6 battery with a constant current on 650mA and when reaching the maximum voltage of 8.4v i changed over to constant voltage and see exactly the same where the current starts dropping! Wow, i really need the camera tomorrow and you made me do it! Best youtuber EU! (i know you're not in the EU)
I was thinking if you calculated the right resistor, you could rig a transistor in there so that once the current goes too low (the cut-off point), the transistor breaks the connection to the battery.
you gotta try this with your phone's battery. No danger of cheap wall usb chargers and faster charging.
That would be an interesting arduino project : LiPo smart charger.
Thankyou for this simple to understand tutorial. I now understand, mystery revealed :)
3.25V is not always a dead battery, that depends on the specific cell.
I have cells that won`t die untill around 2.5V resting voltage..
(18650 high drain cells, both my sony`s and samsungs can live at 2.5 and 2.75V respectively, as long as they don`t SIT at that voltage over any period of time. I regularly have them down to 3.4..)
Nice one again Daveo, totally trusted content. The absolute best.
Hi, actually using lab power supply can be little bit tricky - if your power supply can also sink current (like mine does) it could easily damage your battery - in case of (even brief) AC power failure the power supply defaults to 0V/0A and sinks current from the battery down to 0V and destroying it. Yes, I can program it to default to 4.2V/0.01A but this can be dangerous if you forget about it and work on something sensitive afterwards. For charging liion cells I use simple boards from ebaywith IC TP4056. I bought like 5 of them for $2. Input is 5V from USB and output 1A (lower currents configurable by changing single resistor). It also properly terminates around 10% of set current.
Out of everything on my bench the Rigol DP832 power supply is the most sensitive to power surge and flickers. I've seen it reboot were the scope and bench DMM stayed up. My house has a lot of power flickers, constantly resetting clocks, DVR not recording the whole show. That's why I run UPC APC 1500VA backups at my bench and entertainments system. I use a laptop to collect data from my equipment so it stays running on its own battery, but nothing worse then trying to trend something over 24 hours and see temperature change effect and have a power flicker screw up all the data and have to start over.
A series diode should solve this? Maybe put the sense wires after the diode to account for the forward drop?
Very few bench PSU's are 4 quadrant. This can be overcome with a series diode if you have remote sensing to compensate.
@@EEVblog Hi Dave, my supply wont operate in CC mode with a series diode. Will utilizing the remote sensing feature of my Kikusui PMC 18-5A solve this issue?
I'm about to buy my first power supply. I will be charging the occasional cell with it and powering amplifiers and small circuits. Should I be looking for Linear or Switching?
Marshall Smith Are there any adjustable linear power supplies on the market?
WARNING: With Channel 1 OFF. I connected a 26V Lithium battery pack to channel 1 of the DP832 and it damaged the PSU. In Daves words "Magic smoke time". With the channel off the PSU can sink current from a connected battery and this blows something in the power supply. Over current protection was on, so probably that. In contrast, just the day before I had been charging 12V Lithium batteries with no problems at all. Afterwards the display gave the error message “Charge overcurrent protection. Disable the output of CH1”. Now Channel 1 doesn't supply any power but luckily the rest are working.
After some more research I found this Rigol doc on the Batronix website about not connecting active loads www.batronix.com/files/Rigol/Labornetzteile/DP8_DP1_ActiveLoads.pdf. Apparently with the DP800 and DP1000 the channel output is not turned on with a relay so the over current protection / control circuitry is still active even with the channel off. They recommend using a protection diode in series with the battery to charge.
The main manual has this, which I don't fully understand and says it can damage the powered device not the Power supply.
Do Not Provide Power for the Active Load.
In order to avoid the anti-irrigation current which leads to the power control loop out of control and damages the powered device, this power supply can only provide power for the pure load without the current output function.
Hey would you do a strip down of any "vaporizer" regulated battery modules? They generally use 18650 batteries to heat a coil which vaporises liquid. I think it's interesting from an EE perspective because these mods measure the resistance of the coil, and use some kind voltage stepper to allow you to select a wattage for powering the coil.
I bought this same power supply because Adafruit suggested it. I'm glad to see someone else using it. I love my power supply, and yes I do remember when Dave bought this with the upgraded software. It's still nice to see someone else using it.
Can someone quickly tell me how to set the low current cut off that he didn't want to show in the video?
I'd love to get that supply, but it's way too rich for my blood. I have the $50 ebay special,which also can do this but it's a lot more of a bugger to set exact values on.
You press the button underneath the display labeled "current", and dial in the setting the same way you do for voltage.
That's setting the current limit. I'm talking about shutting it off when the current gets too low.
as far as i can tell, he was talking about setting a cutoff timer after x hours. I don't have the supply myself, but there's a timer button visible on the front- maybe that can help. Or just read the manual :)
I have experimented with using python via telnet and VBA (in excel) via VISA to DP831 to status and control. Works very well. DP831 (DP832 would be almost the same to control) is very open and relatively straightforward to control via ethernet. Suspect USB would also be an option.
Python would be my first option for battery charge control. Could also add safety shutdowns by monitor for weird battery behaviour like increasing current over time and OFF the output.
There was some clever front panel tricks hinted at in the manual that may help with with battery charging but I glossed over these as I figured programmatically would be the most flexible fastest approach for me.
My electric drill/flashlight battery charger charges to 4.0V, so that's like 3 times more longevity or even better. Great for the environment for sure.
I also charge my phone up to 75% for the same reason (only possible if rooted).
How do I change my power supply screen to a video monitor like you have in the thumbnail? I could really use that.
Wow, lol.
This will most likely be done in Photoshop, GIMP or some other image editing tool in post-production.
Thanks, Nice and beneficial Video, do you have a video about the rate discharge measurement of the Li ion battery?rate
There is a warning about charging batteries with a DP832 because it isn't designed to handle voltage sources on its output. The supply can't work in second or fourth quadrant (meaning it will become unstable if an external voltage tries to discharge through the supply). Wasn't this on another one of your videos reviewing this supply? Thanks to Róbert Valdimarsson for posting this warning from Rigol about connecting batteries to the DP832 output: www.batronix.com/pdf/Rigol/DP8_DP1_ActiveLoads.pdf Be very careful not to allow the PSU voltage to be set below the battery voltage.P.S. Why the hell does IE wreck the formatting of a comment whenever you try to edit it?
I do recall similar warning from another forum re other PSU.
Quote "You want to be very very careful hanging large batteries across power supplies.
Astron has a 723 based design, which has a crowbar on the supply
output. The intention is that the crowbar will prevent equipment
damage if the pass transistors short or the regulator goes high. What
happens with batteries on the output is that it also shorts the
batteries, and may cause a fire.
Always put a fuse between PS output and the battery!."
Awesome video Dave!
Well done.
Its cool but the smart chargers for these are incredibly cheap on ebay/aliexpress these days, the days of the 80 dollar smart chargers is over. I use a liitokala, also measures capacity with a charge/drain test.
:-D liitokala = flying fish in finnish
Äijä mittaa jollain kalalla kapasiteettia. :D
I have a confusion..
While you say the charging current should be 1/2c.. so for a 3400mah , it is set at 1700ma
But what about when charging a power Bank made out of say 2 of these.. What should be the charging current then..
And, if the constant current is set at lower than 1/2c, i understand it will take longer to charge, but does it have any effect on its life span?
Also, at some point you said that the constant voltage phase reduces life cycle..so does that mean we should omit it ?
At what percentage of battery capacity does that constant voltage phase usually start?
So is there a range in which there is a maximum life span?
Is it the recommended 20-90 percent?
Super Video Dave !
@8:10... "PING" --- we have ALL been waiting for that y'know... LOL HAHAHAHA!!!
Hi Dave, could you please comment on the document from Rigol "Active loads and the RIGOL DP800 and DP1000 Series". It says "an external diode should be used to prevent the flow of current into the supply and prevent damage of the power supply".
But the problem with a diode... the voltage drop depends on "forward" current. I think it will be hard to apply precise 4.2V to the battery.
Brill. Thanks Dave.
Rigol DP 832 get out of my dreams and onto my work bench...
Hi, it was a beautiful dream, has it already happened? Owon ODP3033 will get out of my dreams on my work bench next week :)
thank you for talking about slowly rising voltage when in constant current mode but i saw something when i charge the battery with constant current mode . the voltage drop across battery was 4.2 v or around that. and voltage across the cell before charging was around 3,8 . so why is it behave like this. isnt it should be 3,8 v across the cell while charging it with constant current and slowly rise the voltage naturally like you show in the video ?
Have done this with one battery no problem, but if I do the same with 8 batteries in parallel, I still only get the same current as if I would charge one battery. So it will take 8 times longer to charge them together rather then one at the time. Why is that? It doesn't make sense.
Cool video! Thanks Dave!
Funny thing is I only recently received my DP832 bench power supply and have used it to charge a couple 18650 batteries.
"you don't want to actually uh trickle charge or float charge lithium-ion batteries like this because it can actually uh build up or plate the uh lithium inside the metallic lithium inside the battery and yeah you don't want to do that they're not designed for that there are um there are chipsets designed for float charging and they use like a pulse uh a slow pulse"
-- Is the same true of the trickle charge for a dead cell?
Why not just use a mains timer to turn of the PSU after 4 hours?
That could work, assuming the dead PSU won't begin to discharge the battery after it loses power.
I needed this video. It helped me thanks.
On the topic of the charging voltage being 4.20V +/- 1%: Couldn't I just play it safe and not exceed, say 4.1V? I would sacrifice some capacity, but that should be enough to get the battery quite near its nominal capacity, give me plenty of tolerance for my power supply and mitigate the overcharging issue.
He literally says exactly that in the video, at 6:28 ...
Yes you could, as I mentioned in the text overlay. 4.1V is a common safe value.
He actually put a note at the top of the screen about exactly this at 6:26. (increased cycle life at the expense of less charge capacity)
EEVblog Thank you Dave. My bad. Classic case of asking too soon :)
If you do that you will even increase the number of charging cycles before the battery capacity falls down considerably. The only penalty is lower charged capacity (when charging to 4.1V instead of 4.2V), but not much cca. 15% lower.
Source: batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
You little ripper! Love it!!
It's like you read my mind. I would also like to know the differences between charging LiFePO and this one.
Woud like to have seen you put the battery under a discharge tester to prove the success of the charge.
Wasn't this already uploaded already?
It was, in moment when I was typing very long and informative comment and then it gone... :
Wasn't already said already? Love your vids clem :)
I do not want to advertise , but for those interested in a universal charger with good value for money I suggest you use imax v2 B6AC I bought to recycle many 18650 retrieved from the laptop battery packs . Many 18650 batteries such as Sanyo or lg , reach their maximum capacity if charged at 4.30 volts as the data sheet says .
Sorry, but i can't help but notice your grammar is like some Chinese salesman selling products for cheap (but still more than they're worth)
Please check grammar; is it ok now? Sorry for that.. my language is Italian.
Great video bro, but at the beginning of the video you tell that you don't know the cut-off current, albeit it is written clearly on the datasheet and you will reference it later.
That's because I didn't see early in the video when I recorded that.
I was hoping you were going to do a bench supply charging video!!!!
What if one decides to undercharge the cell (to 4.0V say), can you keep the power supply connected indefinitely?
No. Always keeping a li-ion cell at or near its maximum voltage can greatly reduce its life span. For long term storage, they should be at about 3.6v. If you are going to charge it up, use it
thank god for eev. have you see some of the other videos out there....
The bottom and top 20% of li-ion capacity should not be used, as it destroys the batteries prematurely. At the expense of losing Wh/kg (and thereby Wh/$), you can increase the meaningful lifespan of any li-ion battery. This is what is done in electric cars, where longevity is actually expected (unlike a laptop, where people sort of expect the battery to be complete shit in 2 years time)
"The cut off point is 175mA for example, it doesn't show that here"
Nobody reads the datasheets for the data am I right? :)
_Charge: CC-CV 0.5C (max) 4.20 (Blaze it), _*_65mA cut-off_*_ at 25 Celsius_
Think you should have mentioned why the cells cannot be charged in series (@8.4 - 12.6 etc). Also i thought a single was a "Cell" and more than 1 "Cell" is a Battery (which makes this a cell) ? Good work though.
which are suitable power supplies to charge Li ion batteries , and which power supplies are a ""NO-GO "" ?
torches havent been used since electric was invented.... we use flashlights now :P
flashlight is called electric torch XD
lol
They don't flash though
Flashlight/torch is the same thing. Depending on what country, USA say flashlight but UK say torch.
What else can you expect from a nation that calls a liquid "Gas".
Why some people say that this can damage the power supply cause the battery will try to "charge" the power supply after the charging is done? They suggest using a diode and then it can be done.
Great video and explanation!
I'm really interested in the model of the wrist watch this fine gentleman is wearing. I cannot find it on the internet...
Good explanation 👍
LiPo Batteries? Never heard of that abbreviation. So I guess you can call completely discharging a LiPo battery a LiPoSucktion? :)
Great video btw. I always thought you needed complex electronics to monitor the temperature and internal resistanance very accurately or otherwise your battery would explode on overcharging or completely brick it when discharged below a certain level. But I have to stand corrected.
You can do the same, with different voltages and currents for NiCd, NiMh batteries. I've been recharging 1.5V _alkaline_ cells as well with my PSU, works great (1.7V, 150mA). Doesn't work on 9V batteries, though. :(
Since cells vary, how do "smart chargers" determine the proper rate for different cells? Are they all similar enough that they can just use a conservative value?
That's pretty much the case. If you're sure you'll always be charging an 18650, you can use a low charge current such as 500mA and most of the time that will be fine since nearly all batteries of that size are at least 2000mAh in size, except for those cheap Chinese rip-offs. The charging current could be too high for some of those.
On the other hand, some of the tiny flat cells can be as low as 150mAh, so you'd need a charger which goes as low as 75mA to safely charge those. It would take ages to charge an 18650 at that current, so there's no such thing as a truly universal lithium charger with a fixed charging current.
"Smart" chargers generally either assume you'll be only charging a certain physical size of battery or rely on you to set the charge current.
Nice video!
How about batteries with multiple cells in series? Is there a way to guarantee they are balanced using a power supply given the batteries have that additional connector they come with?
Thank you, sir!
I didn't hear you mention the 'precharge' part of the cycle... If the cell voltage is below a critical value (usually around 3.2 volts) it's supposed to be bad to whack lots of current in at first... datasheets I've read say to trickle it up to nominal voltage, and _then_ go to the main constant current charge mode.
I'm not sure of the exact chemistry reason, (may be a LiPo thing more than LiIon) but the feature's built into charger chips at a hardware level, so it's probably important. Not usually an issue unless you run batteries flat and then forget about them for months. But isn't that what happened here?
I did briefly mention it and covered it in my previous tutorial video linked in.
Yep. Many charging IC's do a soft start at 10% of their normal charge current if the cell voltage is
EEVblog Ah, sorry. My bad. Must had missed it. I watched the first one ages ago.. clearly I forgot/missed it there too.
We can use a timer on the Wall plug for 4h then cuts of the charger
1 what is the red line on the graph in the data sheet
2 when you go to constant voltage, how, why does the current drop. Its pretty clear what happens in the constant current phase, but then what is the magic
A question. Say that you wanted to charge a battery while it's in use. Similar to how a laptop charges it's battery with the power on. I take it that all you would need is a battery charger in parallel with the battery that is capable of putting out enough current both to power the device as well as top up the battery. Since the charger would limit voltage to 4.2 and reduce amperage as the battery charges, this should work right? I want to convert a remote control vehicle to be able to self charge with a dock and always be on, for a security robot.
I charged it with my voltage supply, like you said.
But now I measure the cell delivers 4.14 volts, instead of 3.8
Nice!!! this is the video i needed!!Nice explain!!😁TKS
very informative. thanks.
The battery specs seem to be really conservitive on the charge rate, 0.5c . 4 hours though seems really long for charging at 0.5c though. at 1 c the charge time should be around 1 hour.
Though maybe these cells have much higher internal resistance than higher performance batteries.
My RC helis can charge safely at 2c which takes about 40 minutes. But those batteries can be discharged at 35c so internal resistance is fairly low.
As an added safety note, lipo batteries should not be left charging unattended.
Just checkout rcgroups thread lipi fires are real!! for plenty of stories about lipo fires. with higher capacity batteries the fires can start very fast and grow large in short periods of time.
Very large batteries will burn furiously for over 30 minutes on its own without any other combustable materials nearby.
on a simpler power supply just use a timer plug to auto shut down
I have some questions.
When at the phase of Constant current. Your lab power supply will force the current deliver to always stay at 1.7 A, right ? While the voltage from your PSU does not matter as long as does not pass 4.2V limit.
And when the the voltage is at 4.2, your lab power supply will maintain the voltage at 4.2 from your PSU and let the current sinking?
I'm a bit confused.. Why does it say 3.7V on the battery but we charge it to 4.2V?
...Even the datasheet says to charge it at 4.2V but the "nominal voltage" of the battery is 3.6/3.7V
Have you played with some MPPT solar charge controllers? I'm wondering if there is one useful solar charge controller that can charge a pack of 18650 equipped with a BMS? The only one that I could find and can be programmed via their software on a PC is ProStar MPPT from MorningStar and it's like $480, Some other manufacturers charge a $150 fees on top for factory programing.
You can now get solar charge controllers which can be switched between modes to charge either lead-acid batteries or lithium batteries.
In before the next reupload :)
So the voltage with which the battery is charged should always correspond exactly to the voltage that the battery has at exactly that point in time?
how the hell do you manage to make everything interesting?
Keep up the good work Dave!
Thanks nice tutorial.
Few questions,
1.In cc mode if voltage supply exceeds 4.2 v does it damage battery before it reaches cv mode?
2.Can u plz explain how ev dc fast charging works?
3. Also how charging efficiency is managed.
Thanks a lot Dave.
Dangerous? Like Note 7 charging dangerous? :)
Excellent! Thanks.
Thank you for this and what you do.
I'm still learning EE for personal projects.
Instead of an egg timer, watch, or smartphone alarm. Wouldn't it be ok to just plug the power-supply into an outlet-timer?
Absolutely. And I think he actually mentioned that in the video.