BQ76940: BQ78350+bq76940+bq76200+12S,fail to set the charge current

user5811580

Part Number: BQ76940
Other Parts Discussed in Thread: BQ78350, BQ76200, , BQSTUDIO

I just made a BMS made up of BQ78350+BQ76940+BQ76200+12S.

However, I can not set the charge current.

The bqstudio is listed as below. I have set the charge current to 300mA(for test), however, the charge current is still higher than 1000mA.

What's wrong with me?

over 6 years ago

0 user5811580 over 6 years ago

Intellectual 700 points

I just change the fast charge current in charge algorithm.
Is it ok to set the charge current this way?

0 Matt Sunna over 6 years ago in reply to user5811580

TI__Guru* 81034 points

Hi Wu,

I think you are setting the charge current correctly. However, the BQ78350 cannot directly control the charge current. The information in the 'Charge Current' setting is read by a smart charger. Is the charger being used a smart charger that will read this value on the SMBus and adjust based on this setting?

Thanks,
Matt

0 user5811580 over 6 years ago in reply to Matt Sunna

Intellectual 700 points

Smart charger?
No, I do not use a smart charger.
I think BQ78350 and BQ79640 can support smart charging.
Now, I just want to know the way of charging for BQ78350.
It can not control the charge current at all, can it?
I must use another smart charger for this BMS?

0 Matt Sunna over 6 years ago in reply to user5811580

TI__Guru* 81034 points

Hi Wu,

The BQ78350 and BQ76940 is a gas gauge and monitor. The devices are not chargers. A gauge can provide information to a smart charger IC based on the conditions of the battery (temperature and cell voltage), but it does not do charging.

Matt

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BQ76940: BQ78350+bq76940+bq76200+12S,fail to set the charge current