I am working on a new design that requires monitoring of a 20-cell (~29V max) NiMH battery. We need to charge it, monitor the "fuel level" during discharge and trigger a recharge when it is low. We have been looking at the BQ2040 for the fuel level, possibly the recharge trigger as well (if it can).
The datasheet specifies part values up to 12-cell. Can it handle a 20-cell NiMH battery? If so, I did not see a formula for calculating R11.
Can I configure the BQ2040 to send a digital signal to another IC to start a charge cycle when the fuel level hits a particular (low) threshold?
If there is another chip (or set of chips) that would accomplish this better, I am open to that as well. Our team was also looking at the BQ34Z100/110 as well.
The fuel gauge will be on the main board of the product rather than in a battery pack, if that makes a difference. The battery pack is not user-replaceable.
Fuel gauges are new to me, so forgive me if some of my questions are basic.