drill battery pack charging control

Discussion in 'The Projects Forum' started by peter354, May 8, 2012.

  1. peter354

    Thread Starter New Member

    May 8, 2012
    dont know is anybody can help

    replacing the batteris in my drill pack and found that it has what looks like a thermistior??? to control chaging temp(third connection). unfortunatly when dismantling I shorted it out to + and i believe blew it. i need to renew it as it looks like it feeds relay in charger to switch when fully charged (its a 1 hour fast charge) however dont know what it is . it appear to be connected in series with a resistor ???(again not sure can up load a photo if it helps)
    the thermistor is 2 wire and marked M20 tp118/c 02c if that helps, the resistor 05u-045G
  2. t06afre

    AAC Fanatic!

    May 11, 2009
    A picture would help. Says more than 1000 words. All battery packs must contain some sort of fuse. So I will guess your mystery part is a polyfuse. http://en.wikipedia.org/wiki/Resettable_fuse Can not be sure then. As the battery pack may also contain a thermal switch normally closed. Without proper safety. Your battery pack may be converted to a delayed-action bomb.
  3. #12


    Nov 30, 2010
    Measure it again now that it has cooled off. Some of these are auto-reset.