Charger issue

[Djinn]

I have a 4 button lipo nimh combo charger.
It is saying that my 2s lipo cell voltage is way out of balance and will not charge.

Here is the weird part I test with my lipo tester and both cells are the same and at if I remember right 3.8 (I am not at home)

Bad charger?

 

[Djinn]

Got home tonight and checked the battery both cells are the same, plugged it in the charger started to charge went well for about an hour then giving me the same thing.

I might have found the solution and problem.
It has been warm here and the charger might have been over heating. Put a fan on the charger and battery charged to full.

Going to run this pack out and test the theory.

Back after I have some fun

 

[Dustin Mustangs]

Be careful with this until you get it figured out. Lipo fires are serious business and anytime weird stuff happens when charging is cause for concern. It is more important, for your safety, that the cells come off the charger at the same voltage and never more than 4.2v. The battery, charge leads, and charger could all be suspect.

Can your charger measure internal resistance? If so, what does it show??

 

[Djinn]

Yes I understand that they can be dangerous,that is my concern.
Funny thing is the battery is balanced and never over even when it errors out.

By measuring resistance do you mean showing the volts per sell as it charges?

 

[Dustin Mustangs]

IR is a quick and easy way of measuring a packs health in terms of resistance as measured in milliohms. It is kind of a useless number unless you have something very similar to compare it to, like the other cells in the same pack or an identical one. If your cells are balanced before and after charging, it is pretty reasonable to rule out the lipo.

 

[Djinn]

I balanced my pack again this time with the fan on the charger and battery the whole time.

Not a problem at all, I am thinking that the charger was over heating and creating the error. I am going to take it apart and put in a fan for the summer months.