Drill battery charger outputs.

[braniff]

1) With an old Hilti charger, TCU12/24M - according to the label, input 240V, output voltage is 12V. I have no battery to try it with and I've never actually used the charger. I just want to see whether its serviceable.

Anyway - green light comes on. It has five terminals in the hole. Voltmeter across various combinations of terminals gives either a few mV, or 5.61 V (five point six).

Is this because the charger doesn't raise the output until a load is sensed? i.e. a battery is inserted?

2) With a 14.5 V DeWalt charger, which is in frequent use and works fine, when I put a voltmeter across the two terminals I get a reading of 51 V (fifty one). Can this be normal?

Thanks very much.

 

[SammyInnit]

51v sounds irregular.

5.6 over 2 pairs will give you nominal 12v probably for cell balancing and the 5th terminal will be some kind of communication such as temp sensor or overload, cut off etc.

 

[braniff]

Thanks Sammyinnit.

I just measured my other DeWalt 14.5 volt charger - it also reads 51 volts!