If you are in need of a great battery charger or want to learn some more about how a dedicated power management controller gets configured this project by K.C. Lee is worth a look. It uses the Microchip TC4426A Power Management IC to manage the charging and analyzing of two batteries.
“This is a useful tool for determining the charge/discharge characteristics of batteries which help you reuse or for fixing/maintaining batteries. With your own firmware, this could be used as a programmable dual electronic load/current source/power supply.
* Dual channels. Each channel can operate independently. (Scalable to higher number of channels and/or power)
* Efficient switch mode power supply for charging/discharging reduces cooling requirements
* High frequency (~200kHz) PWM – smaller L&C and less ripple current
* Battery parameters are user programmable for different battery types
* Stand alone or operate from a Windows PC
* Flexible power source – USB or external power supply
* Battery voltage is not limited by external supply voltage
* Reverse polarity protection “