160W Buck/Boost solution

Hi there. I have two LiIon batteries. The main battery has a 10s2p configuration with 18650 cells. The extender battery has 8s2p configuration. I use both batteries in the full range. The main battery from 42V after charge down to 28V after full discharge. The extender battery from 33.6V down to 22.4V. I want to charge the main battery with a constant current in the range of 2 to 4 A (not fixed yet) from the extender battery. This should work in any state of charge of the two batteries. E.g. The main battery is empty and the extender battery is full --> buck. The main battery is almost full and the extender battery is almost empty --> boost. I think the 4 switch topology is well suited. I had a look into the MP8860, but obviously it doesn’t fit because of the voltages. Is there a possibilty to use a similar chip but with external FET’s?
What could you recommend?

Hi Erich,

Thank you for contacting MPS. We may have a buck-boost controller that could work for your application, but I may need a little more information about your application. Can you tell me what input voltage you are working at as well? Please email me at mpsnow@monolithicpower.com and I can help you out.

Brendan Schoemehl
Field Applications Engineer
Monolithic Power Systems | MPS Now