Battery Trouble

[Donovan]

Yesterday one of my lipos somehow got down to 4 volts. So I tried to charge it on "Fast Charge" because it would give me a low voltage error if I tried to charge it on any other settings. Well... that wasn't such a good idea because now one cell is at 3.2v and the other is at 4.7v. I think if I can somehow discharge the one that is at 4.7v I might be able to balance it. Got suggestions?

 

[gotnitro]

Drop it in a salt water bucket and pull out the wallet. No point in playing with that anymore.

 

[Sandracer_NL]

You could try using the ‘discharge’ setting on your charger. Monitor the cell values on the screen to see if the 3.2v isn’t getting lower.
Keep in mind you may need to buy a new lipo.
Unless in an absolute hurry always balance charge instead of fast charging.

 

[loryriga]

If you have a good charger it should be able to balance it since now both cells are above 3.0V.
Some chargers also have a "balance only" function.
Anyway, if a cell went up to 4.7V it's likely to be toasted. Be careful, overcharged lipos can end up in flames!
If it happens another time, try to recover it by using the Ni-Mh charge function with the smallest possible current until the cells reach 3.0V each. That's the standard practice

 

[Donovan]

You could try using the ‘discharge’ setting on your charger. Monitor the cell values on the screen to see if the 3.2v isn’t getting lower.
Keep in mind you may need to buy a new lipo.
Unless in an absolute hurry always balance charge instead of fast charging.

I am afraid the 3.2v one will discharge too much if I try the discharge setting. I only used fast charging because I was getting a low voltage error with the other settings.

If you have a good charger it should be able to balance it since now both cells are above 3.0V.
Some chargers also have a "balance only" function.
Anyway, if a cell went up to 4.7V it's likely to be toasted. Be careful, overcharged lipos can end up in flames!
If it happens another time, try to recover it by using the Ni-Mh charge function with the smallest possible current until the cells reach 3.0V each. That's the standard practice

Is there any way to discharge only the 4.7v cell? Also, I have an Imax B6 charger.

 

[loryriga]

Not sure if the b6 can start balancing a overcharged battery. Of you want to discharge just the 4.7V cell and have a couple of connectors laying around you can make yourself a cable that takes the voltage from the lipo balance connector, only from that cell and goes to a power connector, so you can discharge it as a 1s lipo.

 

[Donovan]

Not sure if the b6 can start balancing a overcharged battery. Of you want to discharge just the 4.7V cell and have a couple of connectors laying around you can make yourself a cable that takes the voltage from the lipo balance connector, only from that cell and goes to a power connector, so you can discharge it as a 1s lipo.

View attachment 290440

Cool! I'll give it a try!

 

[RedOctobyr]

Or discharge it as NiMh, etc. Using a LiPo mode, if you tell it it's a 1S battery, it may error out, since it should never be >4.20V.

4.7V is WAY too high. I would store this battery outside for now, and do the charging operations outside. Assuming that things are reading correctly (which I guess I'm a little bit skeptical of), then that cell is wildly over-charged. To get one cell only back to 3.2V, and the other to 4.7V, sounds strange. Even if both cells started at 0V, one cell has only been charged very-little (10-20%?), and the other has been charged well-past 100%.

If you ever run into a case of it being too-discharged to charge as a LiPo, do as @loryiga said, select a low charge current (like 0.5C tops), and do an NiMh charge for just long enough to get both cells over 3.0V. Then stop it, and do a balanced LiPo charge from there.

But please, treat this battery very carefully, the risk of a fire is much higher than normal. I think the safer thing would be to discharge it to close maybe 1V overall, and throw it away. But at least be very careful until getting it back under 4.2V/cell.

 

[LibertyMKiii]

I have had some way out of balance and been able to bring them back from what I thought was "the dead".
You just have to give them lots of time to balance out. Then discharge and re charge to get it back on track.

 

[Donovan]

Or discharge it as NiMh, etc. Using a LiPo mode, if you tell it it's a 1S battery, it may error out, since it should never be >4.20V.

4.7V is WAY too high. I would store this battery outside for now, and I do the charging operations outside. Assuming that things are reading correctly (which I guess I'm a little bit skeptical of), then that cell is wildly over-charged. To get one cell only back to 3.2V, and the other to 4.7V, sounds strange. Even if both cells started at 0V, one cell has only been charged very-little (10-20%?), and the other has been charged well-past 100%.

If you ever run into a case of it being too-discharged to charge as a LiPo, do as @loryiga said, select a low charge current (like 0.5C tops), and do an NiMh charge for just long enough to get both cells over 3.0V. Then stop it, and do a balanced LiPo charge from there.

But please, treat this battery very carefully, the risk of a fire is much higher than normal. I think the safer thing would be to discharge it to close maybe 1V overall, and throw it away. But at least be very careful until getting it back under 4.2V/cell.

Good to know.

I keep all my batteries in an empty metal filing cabinet.

 

[Donovan]

I was able to drain the battery with the method loryriga suggested. Trying to balance now.

 

[loryriga]

Nice! Be extra careful with that lipo for the first usages anyway, check that there is no leaking or puffing and that it doesn't overheat, otherwise trash it

 

[Donovan]

Nice! Be extra careful with that lipo for the first usages anyway, check that there is no leaking or puffing and that it doesn't overheat, otherwise trash it

I think I might have to get rid of it anyway because it got puffy.

 

[RedOctobyr]

I will freely admit that I'm chicken. But it's been WAY over-charged, it puffed enough to break the hard-case, and it looks to be under $20:
https://www.amazon.com/Zeee-5200mAh-Battery-Vehicles-Airplane/dp/B08DD38XKV

I would discharge this battery (to like 1-2V total) and throw it away.

 

[Donovan]

I will freely admit that I'm chicken. But it's been WAY over-charged, it puffed enough to break the hard-case, and it looks to be under $20:
https://www.amazon.com/Zeee-5200mAh-Battery-Vehicles-Airplane/dp/B08DD38XKV

I would discharge this battery (to like 1-2V total) and throw it away.

Yeah, I've had a few batteries that did that and their all in the trash. This one is only a few months old.

 

[Donovan]

The battery is currently charging and balancing nicely. Am I crazy if I keep using it? And will the swelling ever go down?

 

[Pinepig]

And will the swelling ever go down?

Only if you quit playing with it.