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Multi-Battery LiPo Monitoring and Charging

Other Parts Discussed in Thread: BQ29412, BQ24735, ISO1541, BQ24610, BQ34Z100, BQ77908A, BQ20Z65

Hi,

I have a complex smart battery system to design. Before I start a more thorough evaluation I wanted to make sure I had covered all the bases that need covering. I can upload copies of the various circuits that I have designed for clarification if need be. 

The first battery is a 2Cell LiPo. For this I was planning on a combination of the BQ20Z95+BQ29412 for monitoring, balancing, and protection and the BQ24735 for charging. The BQ20Z95 and BQ24735 communicate via the SMB and the BQ20Z95 communicates the battery status to an exterior uC. 

The second is a 6Cell LiPo (isolated from the first battery). For this I selected the BQ34Z100 for monitoring, BQ77908A for protection and balancing, and the BQ24610 for charging. None of these systems talks to one another, but the BQ34Z100 talks to a uC through an ISO1541. 

1. Will these five chips, in these configurations, fulfill my needs? I had hoped for two systems of similar topologies to monitor each battery, but this seems unavailable. 

2. Will the BQ29412 behave badly (or not at all) if I dont use the fuse? I would like these two battery systems to be similar in functionality, and as the 6Cell wouldnt contain a fuse I would prefer the 2Cell not to either. 

Thank you

Sam

  • Sam,

    These devices should work well for your applications. You may want to consider using the bq20z65 instead of the bq20z95, since it is a newer generation device. What would be the purpose of using a 2nd level protector, if you do not use a fuse? How would it disable the pack?
    Regards

    Tom