Charging a LiPo battery with load

Question

I have built my own BMS (Battery Monitoring System) that can control the SOH (State of Health) and SOC (State of Charge) of a LiPo battery. It can control every cell voltage (with passive cell balance), temperatures and current.

This BMS is powered by its LiPo battery and also gives supply to a Raspberry Pi (Control circuit) and gives supply to a load (Power circuit).

During the battery charge, I disconnect the power circuit. But the problem is that I don't want to disconnect the Raspberry Pi while it's charging because it does the cell balancing.

I want to buy a battery charger that gives me enough power and gives me the CC/CV curves too but doesn't do the cell balancing (my BMS does it). This charger lets me program this curve via USB.

Is it ok if I connect the charger to the battery directly with the Raspberry Pi connected? The charger has enough power for both, but I don't know if the CC/CV curve survives. Then:

1: Is the RaspberryPi a problem to the battery charger? (I can program the curve)

2: Is it a problem in general, for battery chargers, to charge a LiPo battery with a load attached?

3: What would be the best solution to this problem?

Thank you for your time.

Answer 1

BMS usually connect to battery pack the whole time. The problem that bms might cause is its consume current can effect CC CV algorithm depend on charge current and bms consume current. If bms current too low compare to charging current then we can connect int with battery. If it not, we should power bms with power supply before charger.

Power supply -> Charger (CC-CV) -> Battery

Then we must auto select source to switch to power supply during charge