Top balance problem

[Coaldust]

I have 4 100ah lifepo4 cells that are new and within .5v per cell. I hooked them all in parallel and left them for
21/2 weeks and now all are way out of balance, from 2.9 to 3.2 volts. What is going on??
Any help would be greatly appreciated.

 

[DIYrich]

What voltage did you charge them at?
How long did you wait after stopping charging before taking them out of parallel?
How long after that did you wait to read voltage?

 

[meetyg]

That's not top balancing. Look at the forum resources for top balancing properly.

 

[BentleyJ]

Based on those cell voltages, it seems like there was no current flowing so there was no charging or top balancing happening.

 

[Lt.Dan]

I have 4 100ah lifepo4 cells that are new and within .5v per cell. I hooked them all in parallel and left them for
21/2 weeks and now all are way out of balance, from 2.9 to 3.2 volts. What is going on??
Any help would be greatly appreciated.

If they went from .5v before to .3v after, then it helped a little. But .3v is 300mV. thats ALOT.

You need to put them all in parallel and then charge them to 3.65v.