BQ77216: Utilizing for Vanadium battery

Hi David,

For this Vanadium Redox flow battery, does it actually have multiple cells? Nominal cell voltage is said to be around 1.5V while you mentioned the battery has 40-62V operating voltage and you are considering BQ77216 which is a multi cell protector. 

If there is multiple cells, I think you might want to considering using BQ77915 which has both voltage and current protection. You may need to stack a few of it but it is easily doable with our built in stacking feature.

Best,

Xiaodong

Hi Xiaodong,

It's different from coin cell battery.

there is no cell concept but it's stack concept.

If it compares with Li-ion, one cell voltage is from 40V~65V.

So I thought BQ77216 can be used for this battery with below connection

- V16 to +

- VSS to -

- short VSS to V1, V2 ~V15

Could you let me know below connection is available?

and please suggest proper circuit.

- 3 units stackable

- VC0 of 1st unit to -

- VC5 of 3rd unit to +

- short VC0 of 1st unit to other VCx without VC5 of 3rd unit

You can refer 

Hi David,

In this case BQ77216 would not work since it will look at the voltage difference between VC16 and VC15 not VC16 and VSS. I am wondering if the protection needed here is simply just an overvoltage protector? if so maybe a discrete comparator with a voltage reference providing the OV threshold might be a easiest form. Please let me know if others protections are needed such as UV OC etc.

Best,

Xiaodong

Hi David,

If the customer is ok with the leakage from the divider, I think this solution would work. Thanks.

Best,

Xiaodong