Is my Em3ev charger balancing my pack when using 80% setting

[leelorr]

(question from a Noob that has read here a lot)

I hadn't thought of this until I was reading a discussion here today.
I have one of Paul's (EM3EV) chargers that he has customized for his packs to have 3 charge settings: 50%, 80%, 100%
I have one of his 25R 14s packs (with BMS) and plan on charging to 80% normally for longevity.
When the charger is set to charge to 80% and I leave it on and connected for a while after it has signaled that charging has finished will it continue to balance the pack? Or will balancing only work when I am charging to the 100% level?
Now that I think about it, it seems that the BMS would not know to balance the pack at the lower charge level.
I could send Paul email and ask him, but I imagine he gets TONS of email and thought I would be nice to him. :^)

Thanks

 

[dnmun]

that charger has a latching output that turns off when the charger reaches final voltage. it does not provide a balancing current at all and will not balance your battery pack through the BMS. it can be hacked to repair the problem if you wanna try that.

 

[cal3thousand]

that charger has a latching output that turns off when the charger reaches final voltage. it does not provide a balancing current at all and will not balance your battery pack through the BMS. it can be hacked to repair the problem if you wanna try that.

Doesn't it stop once it reaches a certain current threshold in the CV stage?

 

[dnmun]

no, it stops when it reaches the final voltage set point. it turns off and there is no CV stage. therefore no balancing current.

 

[leelorr]

What about if charged to the 100% level?

 

[999zip999]

Yes.

 

[dnmun]

Yes.

zippie,
if you have one of these chargers will you open it up and take some pictures of the rear end where there are several transistors clamped to the side of the case? then we can explain how to hack it so it will retain the balancing phase at final voltage.

 

[leelorr]

Thanks for the help everyone, I think I will just charge to 100% every once in a while and leave the charger running a bit to balance the pack in case it needs it.

 

[dogman dan]

That sounds like it will do. If possible, occasionally confirm by checking each cell group, to see if balancing is really happening.

I have one pack I cannot easily check. But if it fully charges, and then holds that charge a few hours, then I know for sure the bms has not discharged a high charged cell. It must have gotten pretty balanced. If the charge stopped way early because of one or two high cells, the bms would have pulled them down, lowering the whole pack voltage a detectable amount.

Or, if you get pretty much the full rated ah from a pack on discharge, it must have been balanced that cycle.