Cordless drill charger what does letter T mean next to + and -

Thread Starter

diesalweasel

Joined Aug 28, 2010
36
Hi got a mystery here I'm trying to dianose a dewalt charger. I noticed there is letters on it and it in between the + and - example +T- what does the T function do. Does it.look for resistance or does it look to see if a battery is there

The problem i have is when there is no battery in i will get an out put of around 24v the red light will be lit

But as soon as i put a battery in the red light will go off and not to be seen again i own 3 battery

The power pack shorted on me i found a burnt out resistor and a shorted mosfet i swapped them and the short has not gone

Thank in advance
 

Marley

Joined Apr 4, 2016
476
The third terminal is for a thermistor that measures the temperature of the battery (so "T" for temperature sensor). This is important to prevent over-charging and to regulate the charge depending on ambient temperature.
 

Thread Starter

diesalweasel

Joined Aug 28, 2010
36
Many thanks for your reply. Why were on the subject of letters. On a bosch charger 4 pin out put i noticed this had a letter C so for example + c t - what would this guy tell the charger?
 

LahrenD

Joined Oct 28, 2019
1
Thanks to you, I was able to figure out where the thermal sensor went in an 18v battery I acquired. The charger didn't recognize it without the thermal sensor.
The third terminal is for a thermistor that measures the temperature of the battery (so "T" for temperature sensor). This is important to prevent over-charging and to regulate the charge depending on ambient temperature.
 
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