Thinkpad 10 1-gen battery

[__jacenty__]

Hello.

I got thinkpad 10 1-gen battery which has "unknown state". I got it with discharged battery.

I was able to charge it via +- pins of its connector. Condition of two internal naked li-pol aku is very good ( I tested it after removal plastic bands from battery ). Strange is behaviour of - pin in connector . It seems it is not directly connected to - pins of naked aku. There is voltage about 0.3V between -pin of connector and -pin of naked aku(s). So output voltage on connector is about 3.84V ( after full charge ) instead of 4.14V.

There are 3 additional pins in connector . I do not know what are they for. Maybe tablet itself do something with it ( during pressing power on button ) and it "removes" mentioned 0.3V.

I do not want to open my tablet to check this battery in circuit because I am afraid I damage plastic hooks. Maybe someone know application of this battery outside the tablet so that to check it is damaged or not ?

Regards