Here 4 alkaline batteries used R20 who came from a flashlight. Their voltage is dropped to less than 1,1 volts each and torch was no longer capable of illuminating enough. By connecting these 4 batteries in series a voltage of about 4,4 volts is obtained, then connecting these batteries 4 R6 to a battery via a resistor, these batteries will provide forty milliamps for fifteen hours is ie they will fully charge the battery. And these batteries are still able to fully charge several batteries while they were good for recycling!
Remarks:
- It is essential to use a resistor between the batteries and each battery to limit the load current because a current excessive load could damage the battery.
- In the case of 4 R20 batteries and a battery R6, a resistance of about 75 ohms to limit the current 40 / 50 milliamps. The ideal is to use a constant current source for each battery.
- Do not put in series that the same type of batteries with the same level of wear if the voltage too old batteries will collapse especially if the load current is high, the polarity can be reversed and even the load will be interrupted .
- You can use different types of batteries such R5 x 6 1 R3 to charge and the batteries can provide enough power can charge several batteries simultaneously. Logically we use several large batteries to recharge one or two smaller batteries, the important thing is to respect the load current.
