20 volt dewalt drill battery not charging

#20 volt dewalt drill battery not charging how to

For a DC 20V charger, the desired charge rate would have worked out to 1/16 = 0.1A and 120 Ohms. They are really only exposed to 1.6 watts. This gave me about 3.0Watts of power dissipation using 0.5W resistors-Because I used an AC charger, the 3.0W capacity is more than enough, because the resistors get to rest during the negative AC half cycle. I used a set of 6 resistors to get near my 60 ohms. 2.4Watts / 2 (because of AC tranformer ) = 1.6Watts. 12V * 0.2A = 2.4Watt of heat that will be generated. 20V charger - 8V battery = 12V difference. The fully discharged voltage of a NiCd cell is 0.8V. The nominal voltage of a fully charged NiCd cell is 1.2V. 1.6Amp hour capacity / 8 = 0.2A charge rate. Use 1/16 in the math for DC chargers, or it will kill your packs or maybe start your house on fire. Because mine is an AC output transformer, I had to double that to 1/8th. I aimed for a nice, slow 1/16th C charge rate (capacity divided by 16). I used an AC output pack, so the charger outputs effectively half that of a DC wall transformer.

BATTERY PACKS WILL ACCEPT EXCESS CHARGE CURRENTS WHILE REMAINING COOL UNTIL THEY ARE FULL-AT THAT POINT THEY WILL START TO OVERHEAT AND MAY CATCH FIRE OR EXPLODE. THIS COULD BURN DOWN YOUR HOUSE, PERHAPS SETTING OFF A CHAIN REACTION OF FIRES THAT BURNS DOWN YOUR WHOLE TOWN. MISTAKES IN SELECTING COMPONENTS CAN START A FIRE.

#20 volt dewalt drill battery not charging how to

If you have any doubts on how to do this, consult an expert on the topic or quit. A diode, an LED, and a few resistors are required to make sure the battery pack is charged at a safe rate.