my project is to use a 5 watt solar panel and arduino(nano) to charge group of batteries with different voltages (between 1,5 to 5 volt)

how to auto detect battery voltage and charge it
without overcharging

 

There are dedicated IC's to control the charge of batteries. Some are limited to a single battery chemistry (which dictates the charging strategy) but I've seen some that can be programmed for different battery chemistries. If you haven't seen it yet, I suggest a visit to the Battery University.

Detecting voltage is a poor strategy unless you are charging lead-acid.

If you want a do-it-yourself solution, you should limit yourself to a single battery type. Otherwise it will be very complex.

 

There are dedicated IC's to control the charge of batteries. Some are limited to a single battery chemistry (which dictates the charging strategy) but I've seen some that can be programmed for different battery chemistries. If you haven't seen it yet, I suggest a visit to the Battery University.

Detecting voltage is a poor strategy unless you are charging lead-acid.

If you want a do-it-yourself solution, you should limit yourself to a single battery type. Otherwise it will be very complex.

ok no problem i want to charge a single type but with different voltages

 

Take a look here and see if anything sounds good.

 

Take a look here and see if anything sounds good.

thank u
i need an arduino project like this http://www.instructables.com/id/ARDUINO-SOLAR-CHARGE-CONTROLLER-Version-20/?ALLSTEPS

with voltage range from 1.5 volt to 5