Hi. Thanks for your effort in doing the video: and your patience in following up questions. Couple quesions if you please. (1) You said "I have been able to get 7+ years out of my batteries using this method". So have you done this a few times? I thought this was just the once, on this one? Why I'm asking, is that as I understand it, a sulfated battery is due to a mistake in operation (no offence). But something like diwcharging it too low, then leaving it like that for too long. So that the sulphate deposites grow, and impede current flow. Unless you have a fleet of cars, surely after the first case, it doesn't happen again? (2) You aloso said, "I never had luck with Epsom salts. I just don't care to deal with pouring out acid.... at least not yet". I understand not wanting to drain the acid, but when you said "never had luck with Epsom salts", have you tried that? I ask because I have a few dead batteries, dead from a van standing around not being used, and I was thinking of trying Epsom Salts. But they are sealed, so is much harder to drain and replace the acid. Thanks
I haven't tried the salts. I have multiple cars, so I've done the process more than once. Yes, sulfation occurs when a battery is left drained. That is true. It also occurs naturally over time. Sulfation builds up on the plates and increases the resistance. A desulfator removes this, at least in theory.
@@stem_saving1644 Hi: thanks for the reply. Yeah, I also have a bit of a collection of "Dead Soldiers", i.e. abused lead acid batteries fro aseries of vans ane motorbike. I haven't tried to revive them before: I was always a bit dubious about the whole process. But I'm going to try it now. I also don't think the Epson Salts is likely to work very well: and especially not in a sealed/low maintenance battery as all mine are. And even in a vented/open one, I think it's the wrong direction to go. As long as you have a reasonable amount of electrolyte in the battery, and it's within the desired density (concentration) range, then that's all you can really do. Because you don't want to to mess with the sulphates that are crystalised on the plates: you just want to gently dissolve them, but without damaging the lead underneath. I think the best method is to use high voltage pulses of current, and to limit the intensity and duration so as not to heat the battery too much. You're going to create some H2 & O2 at the plates at anything above around 2.3 V/cell (13.8 for 12V battery) but as you say, you just need to vent that, and top up as needed. That's trickier in a sealed cell: the comments I've seen say that few if anyone has had success in trying to replace water lost to outgassing. And none of the manufacturers say it's a good idea to try it: but of course, it's not in their best interests to make it easier to revive a dead battery....:-0 Maybe one can monitor how much it bubbles, and adjust how aggressively you can adjust you desulphonation by that. A sealed cell is under some pressure due to the valves, and it will only vent if you exceed the valve resistance. It's hard to find actual values for the set-point of the relief valves: I'll try asking Yuasa what they use on theirs. Battery University claims it's often 5psi/35 kPa both vented as well as "other" batteries ("other" = AGM??). And some special designs (Hawker) go up to 345kPa (50 psi) they say. And there's an EXCELLENT posting by a company called Abertax that gives details of their valves. As well as says what pressures theirs tend to work at (17 - 20 kPa). AND even BETTER, they give a nice graph showing the difference in water loss between a valve operating at low pressure of 3.0 kPa and theirs at 170 kPa. They say after 200 charging cycles, it results in +/- 13% MORE electrolyte loss in the lower pressure cell. And they continue to say that for a cell with an 8.0 kPa valve, that it is degassing for the last 10 hours of a 17 hour charge cycle. Whereas with a 20 kPa valve, it only degasses in the last hour. Which explains the reduced loss of electrolyte with a valve pressure > 17 - 20 kPa. If it's 20kPa, then that's equivalent to a head of water of 2.0m ( Pressure = density x gravity x water depth). To test this, you could attach a longer hose to the gas venting port (most have a way to attach a rubber tube to them to vent any H2 in a safe(r) spot). And then put that tube into a transparent tube of water (say a length of perspex tube). If the valve truly DOES open at 20Pa (3psi for our American friends), then as you stuck it deeper than 2.0m, then the bubbles should stop, because the valve has shut. I doubt the valve is set at much higher than that for standard vehicle batteries, because the case is only made of plastic, and too high a back pressure might split it. And for EXTRA marks..... Since the valve is a one-way valve, then the actual opening pressure of the valve also depends on the pressure that the battery was sealed at (let's say 1 Bar), and the AMBIENT pressure. Because I doubt these valves are pressure compensated. Therefore, at higher altitudes, the valve will open easier, due to less ambient pressure, so at 3,000m (about the highest anyone's going to drive a standard car), the ambient pressure is 90 kPa (down from 101 kPa at sea level). And THAT would suggest a VRLA valve might well NOT open before the case started to see too high a pressure. In which case, aircraft might have an issue with sealed VRLA batteries, especially if the fly high. As in, the lower pressure would stop the valve from opening, and the hydrogen would build up inside, until the plane descended to lower altitudes. I dunno if that's considered though, because I looked at the US military spec for airplane batteries that are used in jets (MIL-8565) and it doesn't say ANYTHING About the required valve pressure. It only says that at ROOM pressure, there cannot be any great release of hydrogen. And last... In theory one should be able to inject a bit of water into AGM's to make up the loss if you get a lot of gas evolution. Maybe can drill a hole and thread it to take an inspection bolt. Can add an o-ring. And that way you could masure the pressure as you charged/desulponated. Dang, even automate it with a digital pressure sensor with an Arduino logging it....:-0
I can't speak for the supply, but as long as it can supply a higher voltage than the battery and drive the small low resistance load.... in theory, it could work. Need to carefully watch the currents, voltage, and temps. Current ratings need to be fairly high for the supply.
Excellent work, good job please let me know in details like how man amps and volts should i give it to batteries like 65AH,100AH,150Ah,200Ah,250AH capacity for 15 minutes and also do i need to set the voltages if yes please tell me how much set the voltages for 65AH,100AH,150Ah,200Ah,250AH batteries also if bigger the battery desulfation time should be increase or 15 minutes for all of these batteries 65AH,100AH,150Ah,200Ah,250AH are enough i am waiting for your reply thanks
There isn't a one size fits all setting. I don't want to give that impression. There are many factors to consider.... amount of sulfation, age of battery, battery voltage, cabling....etc. Make sure you disconnect the battery from the circuit before you attempt this and monitor temperature very closely. Each battery potentially has it's own profile so you need to experiment with what works. Some heavily sulfated batteries need multiple cycles and higher voltages to work. Hope that helps
Hi, it's been a year since you made this video. I wonder if the battery you saved is still in service? I read elsewhere that the way you did is basically using high voltage to loosen up the sulfate deposits on the + plates of the battery. There are chemical ways of using Epsom salt (MgSO4·7H2O) and/or EDTA to desulfate the battery, and I heard sometimes it could bring back well over 90% of the original capacity and CCA of a battery. Perhaps you could get better results if you combined the physical way and chemical way.
It was until recently. It developed a short internally. I never had luck with Epsom salts. I just don't care to deal with pouring out acid.... at least not yet. I have been able to get 7+ years out of my batteries using this method.
The acid profile should theoretically stay the same. Water is the only thing that should really be replaced, during the process. Only with deionized water.
Could you explained theoretically this trick you made with this short circuit in order to measure the battery's capacity? Was it a kind of measurement of a voltage drop on the battery's internal resistance and inferring from that a capacity? You could explain it not only theoretically actually, but practically too since it is not visible on the video how your equipment has been hooked up (and what this piece of copper metal does in the short circuit). By the way, isn't it too short a time of such a short circuit to measure any voltage on an ordinary voltmeter?
It's called a current shunt. It measures current in terms of voltage. It was used not for capacity, but to show instantaneous cracking amps and the ability to bring back a sulfated battery.
@@stem_saving1644 Still don't quite understand. Was this "piece of copper" a low resistance resistor, across which you have hooked up your mV-meter in order to estimate the highest current one can draw from the battery? If so, how does this relate to estimating the ability to bring back a sulfated battery? I guess although you can estimate the highest current (a cranking current) roughly in this way, you won't be able to say much about the chances of bringing the battery back to life, will you?
Your correct. The shunt is for all practical purposes a low value wire that has a resistance. Which you can determine the voltage based on current. When a battery sulfates, it's internal resistance goes up which causes its power output to go down. This manifests itself in reduced or no cracking amps. As you desulfate Resistance goes down and current output goes up. As you desulfate the amount of current you source should increase as well as how long it can be sourced. At least in theory anyway... If you were to take the battery and connect it to a load tester. It's CCA should go up as well as capacity. I didn't take it that far though.
@@stem_saving1644 Thanks. Could you please explain what CCA means? Do you mean constant current discharge or this thing which I don't quite understand which one can see on some manufacturer's discharge graphs and is called CA?
@@allegrofallegrof CCA = cold cranking Amps. As far as I know thats the maximum current running through the wires when you short-circuit your battery. The higher the internal resistance of the battery, the lower the CCA is.
@@stem_saving1644 And what were the criteria of ending a cycle (disconnecting the battery)? The temperature of the battery or the "sulfation" voltage's stop in decreasing? If the temperature, how high and why? Thanks for the video.
@@stem_saving1644 Thanks. It is not clear what you mean by the "sulfation" voltage and how it was measured. Was this "sulfation" voltage simply voltage on the battery's terminals while charging?
Yes. It's really just the extra voltage due to the internal resistance of the sulfation on the battery. As the battery desulfates, the voltage will decrease to the batteries nominal voltage.
Hi. Thanks for your effort in doing the video: and your patience in following up questions.
Couple quesions if you please.
(1) You said "I have been able to get 7+ years out of my batteries using this method".
So have you done this a few times?
I thought this was just the once, on this one?
Why I'm asking, is that as I understand it, a sulfated battery is due to a mistake in operation (no offence).
But something like diwcharging it too low, then leaving it like that for too long.
So that the sulphate deposites grow, and impede current flow.
Unless you have a fleet of cars, surely after the first case, it doesn't happen again?
(2) You aloso said, "I never had luck with Epsom salts. I just don't care to deal with pouring out acid.... at least not yet".
I understand not wanting to drain the acid, but when you said "never had luck with Epsom salts", have you tried that?
I ask because I have a few dead batteries, dead from a van standing around not being used, and I was thinking of trying Epsom Salts.
But they are sealed, so is much harder to drain and replace the acid.
Thanks
I haven't tried the salts.
I have multiple cars, so I've done the process more than once.
Yes, sulfation occurs when a battery is left drained. That is true. It also occurs naturally over time. Sulfation builds up on the plates and increases the resistance. A desulfator removes this, at least in theory.
@@stem_saving1644 Hi: thanks for the reply.
Yeah, I also have a bit of a collection of "Dead Soldiers", i.e. abused lead acid batteries fro aseries of vans ane motorbike.
I haven't tried to revive them before: I was always a bit dubious about the whole process.
But I'm going to try it now.
I also don't think the Epson Salts is likely to work very well: and especially not in a sealed/low maintenance battery as all mine are.
And even in a vented/open one, I think it's the wrong direction to go.
As long as you have a reasonable amount of electrolyte in the battery, and it's within the desired density (concentration) range, then that's all you can really do.
Because you don't want to to mess with the sulphates that are crystalised on the plates: you just want to gently dissolve them, but without damaging the lead underneath.
I think the best method is to use high voltage pulses of current, and to limit the intensity and duration so as not to heat the battery too much.
You're going to create some H2 & O2 at the plates at anything above around 2.3 V/cell (13.8 for 12V battery) but as you say, you just need to vent that, and top up as needed.
That's trickier in a sealed cell: the comments I've seen say that few if anyone has had success in trying to replace water lost to outgassing. And none of the manufacturers say it's a good idea to try it: but of course, it's not in their best interests to make it easier to revive a dead battery....:-0
Maybe one can monitor how much it bubbles, and adjust how aggressively you can adjust you desulphonation by that.
A sealed cell is under some pressure due to the valves, and it will only vent if you exceed the valve resistance.
It's hard to find actual values for the set-point of the relief valves: I'll try asking Yuasa what they use on theirs.
Battery University claims it's often 5psi/35 kPa both vented as well as "other" batteries ("other" = AGM??).
And some special designs (Hawker) go up to 345kPa (50 psi) they say.
And there's an EXCELLENT posting by a company called Abertax that gives details of their valves. As well as says what pressures theirs tend to work at (17 - 20 kPa). AND even BETTER, they give a nice graph showing the difference in water loss between a valve operating at low pressure of 3.0 kPa and theirs at 170 kPa. They say after 200 charging cycles, it results in +/- 13% MORE electrolyte loss in the lower pressure cell. And they continue to say that for a cell with an 8.0 kPa valve, that it is degassing for the last 10 hours of a 17 hour charge cycle. Whereas with a 20 kPa valve, it only degasses in the last hour. Which explains the reduced loss of electrolyte with a valve pressure > 17 - 20 kPa.
If it's 20kPa, then that's equivalent to a head of water of 2.0m ( Pressure = density x gravity x water depth).
To test this, you could attach a longer hose to the gas venting port (most have a way to attach a rubber tube to them to vent any H2 in a safe(r) spot). And then put that tube into a transparent tube of water (say a length of perspex tube). If the valve truly DOES open at 20Pa (3psi for our American friends), then as you stuck it deeper than 2.0m, then the bubbles should stop, because the valve has shut.
I doubt the valve is set at much higher than that for standard vehicle batteries, because the case is only made of plastic, and too high a back pressure might split it.
And for EXTRA marks.....
Since the valve is a one-way valve, then the actual opening pressure of the valve also depends on the pressure that the battery was sealed at (let's say 1 Bar), and the AMBIENT pressure. Because I doubt these valves are pressure compensated. Therefore, at higher altitudes, the valve will open easier, due to less ambient pressure, so at 3,000m (about the highest anyone's going to drive a standard car), the ambient pressure is 90 kPa (down from 101 kPa at sea level). And THAT would suggest a VRLA valve might well NOT open before the case started to see too high a pressure.
In which case, aircraft might have an issue with sealed VRLA batteries, especially if the fly high. As in, the lower pressure would stop the valve from opening, and the hydrogen would build up inside, until the plane descended to lower altitudes. I dunno if that's considered though, because I looked at the US military spec for airplane batteries that are used in jets (MIL-8565) and it doesn't say ANYTHING About the required valve pressure. It only says that at ROOM pressure, there cannot be any great release of hydrogen.
And last...
In theory one should be able to inject a bit of water into AGM's to make up the loss if you get a lot of gas evolution. Maybe can drill a hole and thread it to take an inspection bolt. Can add an o-ring. And that way you could masure the pressure as you charged/desulponated. Dang, even automate it with a digital pressure sensor with an Arduino logging it....:-0
Could you use a TIG welder as the power supply as it puts out DC voltage?
I can't speak for the supply, but as long as it can supply a higher voltage than the battery and drive the small low resistance load.... in theory, it could work. Need to carefully watch the currents, voltage, and temps. Current ratings need to be fairly high for the supply.
Excellent work, good job please let me know in details like how man amps and volts should i give it to batteries like 65AH,100AH,150Ah,200Ah,250AH capacity for 15 minutes and also do i need to set the voltages if yes please tell me how much set the voltages for 65AH,100AH,150Ah,200Ah,250AH batteries also if bigger the battery desulfation time should be increase or 15 minutes for all of these batteries 65AH,100AH,150Ah,200Ah,250AH are enough i am waiting for your reply thanks
There isn't a one size fits all setting. I don't want to give that impression. There are many factors to consider.... amount of sulfation, age of battery, battery voltage, cabling....etc.
Make sure you disconnect the battery from the circuit before you attempt this and monitor temperature very closely. Each battery potentially has it's own profile so you need to experiment with what works. Some heavily sulfated batteries need multiple cycles and higher voltages to work. Hope that helps
very good! but why dont take out the battery from the car avoiding spelling acid and fire risk?
You can, but if you watch it closely and know what you're doing.....
Hi, it's been a year since you made this video. I wonder if the battery you saved is still in service? I read elsewhere that the way you did is basically using high voltage to loosen up the sulfate deposits on the + plates of the battery. There are chemical ways of using Epsom salt (MgSO4·7H2O) and/or EDTA to desulfate the battery, and I heard sometimes it could bring back well over 90% of the original capacity and CCA of a battery. Perhaps you could get better results if you combined the physical way and chemical way.
It was until recently. It developed a short internally. I never had luck with Epsom salts. I just don't care to deal with pouring out acid.... at least not yet.
I have been able to get 7+ years out of my batteries using this method.
Would adding a little phosphoric acid help in the desulfidation process?
The acid profile should theoretically stay the same. Water is the only thing that should really be replaced, during the process. Only with deionized water.
How long to have each cycle running, i.e. how long to keep the charger connected each time ?
It's dependent on chargers output. I did 15min and then let the battery cool off.
Could you explained theoretically this trick you made with this short circuit in order to measure the battery's capacity? Was it a kind of measurement of a voltage drop on the battery's internal resistance and inferring from that a capacity? You could explain it not only theoretically actually, but practically too since it is not visible on the video how your equipment has been hooked up (and what this piece of copper metal does in the short circuit). By the way, isn't it too short a time of such a short circuit to measure any voltage on an ordinary voltmeter?
It's called a current shunt. It measures current in terms of voltage.
It was used not for capacity, but to show instantaneous cracking amps and the ability to bring back a sulfated battery.
@@stem_saving1644 Still don't quite understand. Was this "piece of copper" a low resistance resistor, across which you have hooked up your mV-meter in order to estimate the highest current one can draw from the battery? If so, how does this relate to estimating the ability to bring back a sulfated battery? I guess although you can estimate the highest current (a cranking current) roughly in this way, you won't be able to say much about the chances of bringing the battery back to life, will you?
Your correct. The shunt is for all practical purposes a low value wire that has a resistance. Which you can determine the voltage based on current.
When a battery sulfates, it's internal resistance goes up which causes its power output to go down. This manifests itself in reduced or no cracking amps.
As you desulfate Resistance goes down and current output goes up. As you desulfate the amount of current you source should increase as well as how long it can be sourced. At least in theory anyway...
If you were to take the battery and connect it to a load tester. It's CCA should go up as well as capacity. I didn't take it that far though.
@@stem_saving1644 Thanks. Could you please explain what CCA means? Do you mean constant current discharge or this thing which I don't quite understand which one can see on some manufacturer's discharge graphs and is called CA?
@@allegrofallegrof CCA = cold cranking Amps. As far as I know thats the maximum current running through the wires when you short-circuit your battery. The higher the internal resistance of the battery, the lower the CCA is.
How long were the active charging cycles?(time the battery was connected to the power supply)...thanks,good video otherwise
About 15 min.
@@stem_saving1644 And what were the criteria of ending a cycle (disconnecting the battery)? The temperature of the battery or the "sulfation" voltage's stop in decreasing? If the temperature, how high and why? Thanks for the video.
I did temperature to about 120. Need to be vigilant in watching this. Every battery is different.
@@stem_saving1644 Thanks. It is not clear what you mean by the "sulfation" voltage and how it was measured. Was this "sulfation" voltage simply voltage on the battery's terminals while charging?
Yes. It's really just the extra voltage due to the internal resistance of the sulfation on the battery. As the battery desulfates, the voltage will decrease to the batteries nominal voltage.