BQ29209: Overvoltage condiction disable also cell balancer

Stefano Sivera

Part Number: BQ29209

Hi guys,

In my application I have CB_EN in low continuous condition and during charging the balancer mosfets are controlled properly. If the battery voltages are more different, the balancer is unable to perform balancing and one battery reaches overvoltage condition and the OUT pin becomes high.

When OUT becomes high, the charger is disabled to avoid extra charges, but CB_EN continues to be low while the balancer mosfets are both turned off.

What does this mean ? In overvoltage condition also the balancer is disable
Thank you
Best Regards
Stefano

over 2 years ago

0 Luis H. S. over 2 years ago

TI__Mastermind 42060 points

Hello Stefano,

The recommended cell balancing range seems to be between 3-V and 4.2-V (per cell). It may be that in OV, it disables cell balancing, although this is not described in the datasheet. Unfortunately this is an older part and the people who worked on the part are no longer in the company, so I cannot easily confirm this at the moment.

I can try testing this on Monday with one of our boards to see if I see the same behavior. I will be able to confirm it then.

Best Regards,

Luis Hernandez Salomon

0 Stefano Sivera over 2 years ago in reply to Luis H. S.

Prodigy 221 points

Hi Luis,
ok, I understand you for the problem. Your confirm is very useful for me, I will wait your test

Stefano

0 Luis H. S. over 2 years ago in reply to Stefano Sivera

TI__Mastermind 42060 points

Hello Stefano,

I did test with our board. I can confirm that cell balancing stops when OVP is reached.

The device cell balances before this threshold and it continues to cell balance after getting out of OVP.

Best Regards,

Luis Hernandez Salomon

0 Stefano Sivera over 2 years ago in reply to Luis H. S.

Prodigy 221 points

Hello Luis,

I see, thank you for test

Best Regards

Stefano Sivera

Power management

Power management forum

BQ29209: Overvoltage condiction disable also cell balancer