BQ4050: Charging bq4050 based battery pack with external balance charger

Amit Raushan

Part Number: BQ4050

I don't want to get into designing the charger for my bq4050 based battery pack (4S1P). So, I want to use easily available balance charger for that.

Can we charge the battery by keeping the battery cell leads connected to bq4050 as well as connecting the same leads to balance port of balance charger and main port to the pack out of the

battery management system? Would that affect the measurement of cell voltages or capacity measurement or any other functioning of the battery pack?

PFA the rough sketch of the design.

over 4 years ago

0 Abraham Rashid over 4 years ago

TI__Expert 3030 points

Hi Amit,

Does this balance charger charge individual cells directly? If so, then current will not go through sense resistor of the gauge, then gauge cannot calculate energy.

0 Amit Raushan over 4 years ago in reply to Abraham Rashid

Prodigy 160 points

No, charger does not charge individual cells but my concern is once balancing will start then how would bms behave? Will it calculate the energy appropriately? I have already attached the wire diagram in original post.

0 Abraham Rashid over 4 years ago in reply to Amit Raushan

TI__Expert 3030 points

Hi Amit,

If balance current does not flow through sense resistor but through charger, gauge might overestimate RemainingCapacity. You can try to disable balancing if possible.

Best Regards,
Abraham

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BQ4050: Charging bq4050 based battery pack with external balance charger