Charge Lithium cells using Buck/Boost converters?
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- čas přidán 15. 07. 2024
- Website: www.bigtronixs.com/
Contents:
0:00 - Introduction
1:46 - Buck/Boost Converter Overview
3:43 - Output Voltage of SMPS
4:33 - Setting Output voltage in buck converter
5:37 - Connecting Buck Converter to the Battery
8:27 - Charging 12V Battery Pack
10:19 - Boost Converter
11:31 - Charging 24V Battery Pack
We are going to take a look at how to charge lithium cells using the buck and boost conservators.
Buck is a Step down module
Boost is a Step up module
We are using an SMPS supply to either step up or step down the voltages. When ever you use any of these modules make sure that you get the one in which you can control the current.
Note: Always use a fuse in series with the circuit.
Disclaimer: Working with AC electricity can be dangerous, please take utmost precaution before handling these modules. We are not responsible for damages that one might encounter. Please try it at your own risk.
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-- - Věda a technologie
Hello from Las Vegas! I haven't yet perused your channel but if you have more content like this, I will be devouring it in short order. Thank you for sharing your knowledge with an ol' tinkerer like me. Actually, the tinker bug didn't hit me till covid lock-downs started and that's when my love of gadgetry and making stuff converged. I am the one everyone in the family comes to with computer problems, but really it didn't go too much further than that. Also, I discovered I had a knack for fixing things during lockdowns. Once I reconciled that the item was useless in its broken state, and I was sure I couldn't do more damage or even if I could, it wouldn't matter because I wasn't going to pay to have it fixed, I no longer was apprehensive about tearing things down. At the very least, I would learn something about how it worked.
And for my husband who hates having to fix shit (particularly plumbing LOL) this was a bonus, because I hate cooking and that's his happy place, so we traded. That year, I was also gifted a 3D printer and a cnc style die cutter. So down the rabbit hole I went, never to return. LOL
I am looking to restore an electric scooter my neighbor was going to toss and if I have learned anything these last few years, it's that people don't know how to or even that they CAN fix things. Which, when you think about how things are made to break in certain ways, and your ability to work on them is proactively being hindered by the product design (IE., Glass backing glued to your cell phone so you cannot replace the battery easily, even breaking parts in the process) or by denying access to OEM parts, it's not a big jump to assume it's probably not worth the cost and hassle to repair. In those instances, I end up with all kinds of cool second hand gadgets, or worst case scenario, a bunch of cool parts I can salvage. Motors are a fun one for me. Electric ones anyhow. I can work on my car, and often do, but I hate getting greasy. However, I like saving money more. but this scooter is all new to me, so I am in the info gathering phase, which brought me here.
Long story even longer (haha), I have what looks like 60 18650s in both parallel and series. Since we don't use 220v here in the US, I am guessing it's 2 series packs of 30, and all its charging tech is in-built. Just a standard 3 prong 110 cable plugged directly into the wall to charge it. I haven't yet done this because I needed to know what was going on inside and wanted to check the batteries individually if possible to make sure there are no dead cells and parallel charging them back to life. The problem is its pcbs have all been back filled in what looks like epoxy or something, which I get since it's rated as being ip65 water proof, but makes it hard to sus out. I only just started taking it apart the other day, but I found a pretty big fresh crack in the aluminum frame which creates a new opportunity to get the welder out, but if I had to guess, that's why it was on the curb. Lucky me. If I can't use the scooter like it is, The tire motors will be fun on some other frankensteined device. A motorized ice chest, perhaps. Rear wheel drive with some micro controller magic. And ws2812s lol Ape hangers! 😂
Anyway, thanks again for confirming a lot of my suspicions and showing me a couple new things. Inline fuses. Brilliant. Sorry for the novel.
Thanks for the short and concise video. Answered most of my questions. I still have a query though which i hope you will be able to answer. I intend to leave the battery permanently connected to the output end of the converter. Does it drain any current from the battery when not charging?
Nice informative video.
I have a boost converter of 150watts with minimum input voltage of 10volts and maximum output voltage of 35 volts with provision of only voltage adjustment pot.
Now, Can I charge 3S Li-ion batteries with this module ?
Kindly advise me.
Thanks.
hi bro need your help to make a something which can convert vaiable voltage current to CVCC for my lithum phoste battery which is 12v which one you will suggest
...ANOTHER GREAT VIDEO!!!!!
When you charged the 24V LiFePO4 battery, where did you set the current control pot??
Thanks much!!
--daLe
Nice video. Could you please help me. I have exactly the same (15A) buck converter as you. Input is power supply 180W 20V, output is 3S li-ion battery. I've preset 12.6V and 8A on the output. Once I connect battery, input and output voltage and current start jumping to different values from 0 to around 9V (for voltage) and red LED is blinking.
What can be the problem?
so 20V 9A power supply? attempting to step down to 12.6V 8A? Thats about 100 watts. I can almost guarantee that you're using a Chinese power supply and they are all liars about specs. Your power supply is probably 90W max
Do the modules have anti-backflow when the battery is connected without first connecting the module to a power supply?
Yes I have never had any problems.
Do you have a shop in Swaziland
I know of a seller with EVE cells grade A if you want to get some good cells for your collection because you might have some problems using used cells.
Hello sir,1800w dc to dc boost converter charger having auto charging cutoff and reverse protection
No charging cutt-off but only small to no reverse current.
How do you know when the battery is done charging with the buck boost converter?
Probably you will buy some simple power meter between buck and battery, if the power will be 0 than you're done charging
Can I charge 7.4v lithium-ion battery with mobile charger (5v dc output) using step up module
if you can find a boost converter that supports 5v input and 8.4V output. 8.4 is your max charging voltage. Be aware many of the small ones only support 1A or 2A. If it says max 3A, it really means max 1.5A. Adding a fan can help a little.
The only risk of using buck/boost converters without current limiters, which are cheap and ubiquitous. Lithium batteries can and will pull maximum current and you can get run-away heat build-up. Be sure to size your buck/boost converter appropriately or get one with current control that actually works...or you risk melting something. It's the same issue people run into when using a buck/boost converter to run high-powered LEDs. I know from experience.
how much time take 24v lifepo4 cell battery pack ?
that purely depends on the charge that you use.
@@diyIndia I have 24v 80ah two batteries in parallel for inverter. Inverter is taking more power to charge it. It is taking 1400-1500w. And time 7-8 hours.
@@rupeshrathod8123 1920wh per battery, so total of nearly 4000wh. Normal charging time should be 4-5 hours at 1500w because the charge current goes down in CC CV charging. its not as simple as saying 4500wh battery with 1500w charger means 3 hours.
But yes, you do have an unusually long charge time. Either terrible efficiency or something else. You need to put a watt meter before the inverter and after the inverter/before the battery
@@ericklein5097 pls answer my question and help me🙏 I have an 8S LiFePO4 battery pack for my ebike project which I tried to charge using my suspicious lithium battery charger. The charger applied a voltage slightly higher than the battery voltage at any moment to charge it along with 1.5 A of current. For example, if the battery was at 26.2 V the charger applied 26.5 V and 1.5 A, and the voltage increased in the same proportion as the battery voltage increased. This was constant current charging.
The thing is, the charger cut off the charging while my battery was only 85-90% charged(26.6V) and never intiated the constant voltage charge. I just read somewhere that I need a charger which applies a constant voltage of 29.4 V to fully charge a 24 V LiFePO4 battery.
Did I damage my battery by charging it through a charger that doesn't fully charge my battery and give out constant 29.4 V? I may be just paranoid but it could be a serious thing. Can I continue using this charger in the long term which never initiates the CV charging? I'm fine with not utilising the remaining 10% SOC. I just want to make sure this kind of undercharging and this charger doesn't harm my battery in any way.
And what I'm more concerned for is that i also heard that many bms' tend to start balancing the battery when it reaches a certain VOLTAGE (full charge voltage), if this is true..... doesn't it mean that my battery can become unbalanced in the long run as the bms may never balance the cells?
Can charging an 8S LiFePO4 battery pack using a charger that never initiates constant voltage charging and doesn't fully charge the battery to 100% cause damage to the battery, and can this lead to cell imbalance if the BMS only balances the cells at full charge voltage?
@@electricalA.K. You can safely charger with the charger you have without damaging to the battery. Now a days most of the BMS uses active balancing algorithm in that the balancing happen while charging and discharging the battery. But I don't know the specification of your BMS you can keep an eye on your bike range (KMs) after full charge if the cells gets disbalanced you will notice a huge change in the range drop. That means your BMS not doing active balancing. The solution would be get a LFP charger with max voltage of 29.4 V. And choose the Amps depending on your battery capacity. You mentioned balancing happens at after full charge that always happens for the lead-acid batteries, they simply overcharge the battery once in every month or so for balancing the cells as lead-acid batteries don't have a BMS.
Very very great job on this video. You need to practice pronouncing your letter "v". I keep hearing "woltage. Very distracting.
Do the modules have anti-backflow when the battery is connected without first connecting the module to a power supply?
Yeah that's what I'm wondering. Doesn't look like he's answering comments.
I guess it probably needs a diode or something like that in place.
I have experience with the smaller two buck converter modules and both of them have back power flow problem which you have mentioned. But can avoid that by adding a suitable Schottky diode in series in the output terminal. I have not used the other bigger boost conver module but planning to get one to charge my EV battery.
@hikundu Appreciate this tip. I was just fiddling with this today and watching the fancy lcd screen on my little meter jump all over the place. Schottky diode. killer...