Isdt charged cells differently...

[baevans11]

I was charging some 2s lipos and my isdt charger put one cell at 4.35 and one at 4.15 on all three lipos that were on a parallel charging board. I double checked the settings and it was set to charge to 4.2 as it always is. Does anyone k ow why this has happened? Thanks!

 

[HighTechPauper]

If it is on a parallel charge board all the batteries will be exactly the same since they are actually shorted together and the cells will "balance" with their partner cells in the other batteries, that's not the weird part, if your charger was mis-calibrated, which iSDT's often are, then all charging should have this mismatch. Do 3s and higher batteries charge ok? And do they charge to 4.2 roughly? It is possible to calibrate iSDT chargers yourself, but you kind of need a calibrated voltage meter to do it. Don't trust the LED segment on a parallel board, or even a battery checker as they can be way off, check with a voltmeter if you have one to see if they are really that far off.

 

[Captain Nemo]

I also encountered some resistance differences when using parallel charging resulting in cell voltage difference. At least that’s what I thought. Charging single lipo’s solved my cell differences.

 

[baevans11]

If it is on a parallel charge board all the batteries will be exactly the same since they are actually shorted together and the cells will "balance" with their partner cells in the other batteries, that's not the weird part, if your charger was mis-calibrated, which iSDT's often are, then all charging should have this mismatch. Do 3s and higher batteries charge ok? And do they charge to 4.2 roughly? It is possible to calibrate iSDT chargers yourself, but you kind of need a calibrated voltage meter to do it. Don't trust the LED segment on a parallel board, or even a battery checker as they can be way off, check with a voltmeter if you have one to see if they are really that far off.

I just charged a single lipo and both cells were balanced. But it's always balanced the cells nicely when charging up to 6 lipos. It does charge my 4s lipos fine but then again it has always charged my 2s lipos fine too. Here's the really weird thing. Right before this round of charging I charged some lihv 2s lipos. They charged fine @ 4.35 which is what one of the cells on the regular lipos charged to. I know what your thinking, that I left it on 4.35 but I assure that's not the case. I'll be charging again today so I'll post back on how it goes. Thanks for all your help thus far!

 

[HighTechPauper]

I know what your thinking, that I left it on 4.35 but I assure that's not the case. I'll be charging again today so I'll post back on how it goes.

Actually I wasn't thinking you left it on LiHV, since then I would suspect that both cells would have been closer to 4.35, I am not sure what to think actually, but it wasn't that you forgot to change it, more just looking for different charge scenarios to perhaps yield a clue to what could be happening. I think right now I might suspect a bad battery or connection somewhere, perhaps the 4.35 volt charged cells had a bad connection on the balance and that is what allowed it to overcharge because it could not accurately sense the voltage level. I will be interested to see what else you learn since this would be great info for all of us.
Good luck and let us know.