I have this battery out of a Samsung Galaxy Note 10.1

Photo of battery markings

and this battery has 5 wires; 2 black, 2 red and 1 blue wire. I assume that the red wires are positive and the black wire negative charge.

Photo of battery wires

I've searched all over the internet, but no solution. Could someone tell me what the blue wire is for? The battery is a SP3637B1A(1S2P) 7000 mAh from Samsung.

  • \$\begingroup\$ Check this here: electronics.stackexchange.com/questions/10588/… \$\endgroup\$ – Eggi Dec 17 '18 at 10:13
  • \$\begingroup\$ I think the blue wire is for sense lead for charging. \$\endgroup\$ – pantarhei Dec 17 '18 at 10:13
  • 1
    \$\begingroup\$ My guess: the blue wire connects to a temperature sensor, often a resistor which changes its value over temperature. When the battery gets too warm or too cold the charging current must be limited so this way the charge controller has infomation about the battery's temperature. \$\endgroup\$ – Bimpelrekkie Dec 17 '18 at 10:29
  • 2
    \$\begingroup\$ Li-ion and Li-poly are very sensitive to temperature, so I would guess it was a thermistor to monitor the temperature of the cell. Easy way to test would be to measure resistance between that lead and the black one, and that lead and the red one at room temperature, and then after left in the fridge for an hour or so. \$\endgroup\$ – Puffafish Dec 17 '18 at 10:29