Instructables
Picture of Crank Charger recycle
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This crank charger died after a few days. To open it there are 4 screws on the back side. After opening it turned up that charging setup is quite good. Good gears, motor, and rectifier circuit. The problem was in the rechargeable battery. The manufacturer used a cheap low quality battery which dies after a few charge rounds..(even a normal battery can perform a few charge rounds, but do not try that because some may explode or leak)...Lucky that I have so many rechargeable a batteries of different sizes. One from an old Motorola Bluetooth headset. It came perfect size to sit in place of the old battery. I did not snap a picture of the older battery before I throw it away in the battery recycle area. 
One interesting observation is that you van reverse the use of this charger by using it as a geared motor. It has a good gear setup inside it, so if we connect 3.7-5 volts DC direct to the motor we can get a good movement by the crank lever to open a chicken feed door, or can entry ...etc.
Another worthwhile note is when you have any rechargeable item that broke or dies, do not throw simply. Shavers include a motor and battery to take. also chargers, cordless drills, Bluetooth sets, old cellphone...the harvest is worthwhile.
rimar20002 years ago
Good repairing work!

I have one of these crank torch/charger, but it has a super capacitor instead of battery. I have it since 8 years ago, and it have not wasting signals.
pfred22 years ago
I got one of these for free because a resistor had burned out in it rendering the whole unit inoperative. I replaced that but I think there still might be something else wrong with the unit because one of the 3 LEDs still doesn't light up. Mine also has a lithium coin cell in it that fails to take a charge. Now if I crank the handle 2 of the LEDs light up. That is more than it did when I got it. After reading your article I'll have to keep a look out for a rechargeable battery to replace it with.