The charger’s electronics consist of a small 5-V/500-mA solar panel (SP1) linked to a Li-ion battery charger circuit built around the dedicated Li+ charge controller chip MAX1555 ... 1 depicts the ...

[Debasish Dutta] has built a charge controller ... an Arduino. Maximum power point tracking (MPPT) is a method that uses PWM and a special DC-DC converter to match the impedance of the solar ...