In my case it's a flashlight and a camera that uses 4 AA batteries.
A bit of theory. Batteries are chemical current sources, but in contrast to electroplating chemical reactions occurring during the battery life, are reversible. Battery, who gave electricity (a process called discharge), can again provide the initial amount of electricity by charging it. For proper operation of the battery is discharged and recharged up to 1000 times.
Now there are many devices offering accelerated high current charging the battery than the standard charge, and even exceeding it, but once again, only at the recommended charge current of the battery will last longer. In my capacity 1000mAh battery is written: Standard Charge 16Hrs at 100mA (16 hours of charging current of 100mA).
If you have another battery capacity, charge current, you can define or recommendations on the element itself or by the formula suitable for any type of battery:
I = 0,1 / C
where C - the battery capacity in ampere hours.
Actually a schematic diagram of our device:
The main element of the IC LM317T, use in source mode. The input voltage depends on the number of batteries, it must be greater than the voltage at 4V rechargeable cell or the amount of stress a few items. I: 4pcs * 1.2 = 4.8 V, 9-4,8 = 4.2.
To our source gave us the necessary current to 100mA to calculate the resistance of R3 defining this current. According to the formula:
