I need to dimension a Buck boost converter to charge two LiPo battery packs 6s 20ah starting from a variable input voltage. Both packs have their own PCB BMS board. This one: http://bestechpower.com/222v6spcmbmspcbforli-ionli-polymerbatterypack/PCB-D165.html
So I just need to charge them at 25.2 volts—being able to adjust the charging current automatically based on the input voltage. And I would like to charge them at 10 amps maximum.
I have a voltage input that may vary between 12 and 25 volts. Usually is fixed to 25 volts.
What I know is that Lipo batteries need constant current and constant voltage to be charged safely but I didn't find many Information about charging them or designing a charger for bigger packs than 2s.
My questions are:
Do I need to limit progressively the current during the charge? If yes, how do I do that?
Do I need a microcontroller to cut the power automatically when the battery voltage reach 25.2 volts?
Are there any control IC's that simplify the design of a 6s Lipo charger?