Battery switched on or off during charging?

This seems odd to me, but maybe it's a simple explanation. My previous battery didn't have a switch. Separate charge and discharge connectors. My new battery also has separate charge and discharge connectors, but has an on/off switch as well. I usually check the charging progress by viewing the voltage display on my cycle analyst.

I have my charger set to 57.75V to charge to ~90% on my 14S pack.

Here's what I observe with the new battery:
If the battery is off (CA off), and I plug the charger in, the CA comes on and displays the voltage, from the discharge conductors. The battery will charge until the charger cuts out, presumably at 57.75V. If I unplug the charger, and turn on the battery, the CA shows 57.2V.

I have not checked the accuracy of the CA voltage display yet, however, when the charger cuts out, as described above, and I turn on the battery, with the charger still plugged in, the display voltage drops from the 57.75V cutoff voltage, down to 57.2V, AND the charger will kick on. With this behavior, it looks like I should always charge with the battery switch turned on. I'm also guessing that some of these behaviors may be unique to the type of BMS used.

Any thoughts on what's going on, and whether the battery should be on or off during charging?

my ca shows 0.4v lower than my dmm, i figured that 0.4v was because my system was on, kind of like volt sag. youre charger/bms seems to be sensing what your system is using while turned on then pumping amps into the bms to be burned off? id leave it turned off while charging otherwise you might overheat? the bms?? or can you adjust the kick on setting in the bms

goatman said:

my ca shows 0.4v lower than my dmm, i figured that 0.4v was because my system was on, kind of like volt sag. youre charger/bms seems to be sensing what your system is using while turned on then pumping amps into the bms to be burned off? id leave it turned off while charging otherwise you might overheat? the bms?? or can you adjust the kick on setting in the bms

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That's interesting that it's off about the same as what I'm seeing. I'm charging now with the switch on, so I'll test with my DMM when the charger shuts off. I already know that when I have it switched off, the output voltage is lower than what the charger is stopping at.

EDIT: The charger kicked off and I measured the battery discharge connection directly, and it turns out that the CA is spot on. I'll need to remember to keep the switch on during charging. Still not sure what makes the difference though.

On my e bike bicycle manual says off.And then plug to the wall.Aostirmotor Bicycle 750 w. 48 v 13 ma baterry.

Josecolin said:

On my e bike bicycle manual says off.And then plug to the wall.Aostirmotor Bicycle 750 w. 48 v 13 ma baterry.

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Thanks. My concern with the way mine appears to be working is that if I ever do charge to 100%, the charger would kick off before the battery reaches 58.8V and never balance.