How to charge a cordless screwdriver??


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Old 01-28-06, 05:31 AM
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How to charge a cordless screwdriver??

Hi, I want to ask you, how can I charge a cordless screwdriver? Without its original charger, I mean... It is an old model of Black & Decker, KC9019. It works on 3,6 Volts. Can I use a GSM charger at similar volts, or some other kind of charger/adapter, in order to charge it?

Also, does someone have that model, what is written on the charger? /about volts and etc./ Also, the batteries are 3,6 Volt - and what about the Ah?? Thanks in advance!
 
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Old 01-28-06, 06:12 AM
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You need a charger that is matched to the particular batteries involved. It must match both voltage, current, temperature sensor, and battery chemistry/charge termination. Using an incorrectly matched charger will in the very best case charge the batteries and 'work', but over time cause the batteries to lose their water and become useless. In the worst case, an incorrectly matched charger will cause the batteries to explode or ignite.

If you match the polarity and keep the current low enough, then you can be pretty certain of having the first sort of failure mode, which is actually fine for many applications. Any supply limited to about 30mA and 5V should be able to charge this screwdriver. (I am guessing that the battery is something between 250 and 500 mAh.)

Whatever you do, don't try to adapte a 'smart' or 'fast' charger for this application. Slow chargers will _slowly_ cook the batteries if not properly matched, fast chargers _must_ be carefully matched to the battery.

There are general purpose chargers that can be adjusted for different batteries. They require considerable knowledge of the batteries involved, and cost more than the screwdriver that you are trying to charge.

-Jon
 
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Old 01-28-06, 06:35 AM
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Thank you very much for your reply!!! Managed to find a little more information, ithis model is dscribed to have power 3.6V 1.0 Ah. The batteries seem to be Cadmium-based /there is the "No Dustbin" sign and letters Cd on them/.

So, 3.6V 1.0 Ah cadmium batteries - does this help determine the charging method?
 
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Old 01-28-06, 06:40 AM
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If you buy one of the adjustable smart chargers, you can just input that information, slap the temperature sensor on the battery, and charge it.

If you go the simple trickle charge approach (the one that will _slowly_ cook the batteries) then the 1000mAh number tells you that you could safely use a 50 to 100mA current limited charger.

-Jon
 
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Old 01-28-06, 07:14 AM
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Once again, thank you very much Jon! Meanwhile found one owner of a complete set, screwdriver and charger. And according to him the original charger is marked:

OUTPUT 5V---1.25W

MODEL YD-DC-5-250mA
 
 

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