I want to replace my 300 mAh Chinese tablet battery with a 3000mAh new one, My old battery has 3 wires red , black and White, the white one connect to a point on tablet board named "T" which I have been told is a temperature measuring thermistor connection.. but my new one has only 2 black and red.. I connected the red and black wires of the new battery to + and - poles .leave the "T" pole on the board unattached .. The tablet worked with the new battery just fine .. BUT the problem is that I can not charge the new battery .. I connected the charger for one hour but the battery charge level never increase even 1% I think this is because the "T" spot on the board is not connected to battery .. what can I do ?
There is a convention that the "T" wire is connected to ground via a 10kOhm NTC, as mentioned for example on this thread on AnandTech. Replacing it with a 10k fixed resistor should enabling charging, but on your own risk. The sensor is used to prevent charging when the battery is too cold or too hot (possibly caused by environment temperature) to avoid damaging the battery. Also it can be used as an emergency cutoff if the battery gets too hot during charging. A fixed resistor will disable these safty functions.
I know this is an old topic, but I thought I would throw this in so that those who stumble on this topic through Google have a solution. I had the same problem. I purchased a two wire battery, installed the battery, then found that the tablet ran fine but would not charge. To solve this, I soldered the white wire to the black wire. Seems to be charging now.