My kids got a new toy for birthday They were very disappointed with the performance of original battery 700mA which i suspect that is much lower. I decided to cheer them up by fixing their toy
Step 1: Creating the charger
I used old HTC charger 1Amp and old USB keyboard. I connected with the improvised connector with Black and Red wire. Since batteries are 4V i use 5 Volt standard charging (for mobile). Its very important to use 1Amp charger not less (since many cheap products mislead costumers).
Step 2: Parts
My fathers laptop battery died. I purchased new one but decided to see what in the old battery. When opened i saw an electronic chips (which probably regulates voltage input and output) with 6 batteries. Batteries where arranged in series of 3 series of 2 parallell batteries. In short every battery has 4 volts x 3 series to make an output of 12v ( or 11.8 ).
In picture you see 2 of 3 batteries pack extracted from the llaptop battery . Other battery is original one (700mA) .
Step 3: Result
Last and not least.. Laptop battery electronic chip protects battery from overcharging. Be carefull not to charge beyond their voltage. In my case, after disconnecting from charger i check the voltage of batteries with multimeter. If it is around 4.0V its OK.
I tested the car myself for an hour...The results are impresive. Even my kids don't have nerves to discharge the battery.
Never throw away llaptop batteries. They are very high quality and can be useful for anything