GPS Navigon A12XL not charging.

[thesame]

The unit had a battery replacement , it used to work with a 2200 mah battery that i have found swollen, i have replaced it with a 1500 mah battery( i couldn't find one available at 2200mAh), tested working, after 2 months of beeing used in the car always plugged to the charger the owner sayed that it's not charging, the battery had 3.3 v instead of 3.7 , i have installed a new battery of 1500mAh, the unit powers on , shows 1% battery and it only draws current when the display is on and only shows the charging icon when i first plug the cable in then it stops after 10 or 20 seconds,and if i turn it off it restarts. The battery has 3 wires , i have voltage at battery pins on the board, i have tryed with two different batteries, i can't find a schematic for it, i don't know what else to check, if someone can help with an advice!?

[mon2]

Post clear pics of the original and replaced batteries. These batteries usually feature an onboard bms board to deal with the charging.

[thesame]

In the upper part it's the original one, and the black one is the one that i have replaced it with.

[mon2]

Is the black replacement with 2 leads or 3 ? The original battery contains a BMS board which is the actual charger circuit and supervisor to safely charge the battery. You apply a voltage and usually the 3rd lead is used as a gauge of the battery temperature (feedback). If the battery gets too hot, this thermistor reading will be sensed by the host board to cut off the charging voltage.

As far as I can see the black battery is 2 leads only and is a 'dumb battery'. This type of battery expects to be charged by an external charger circuit. This is only the raw battery packs inside of a hardshell. Check Amazon for a suitable 3 legged battery pack which will contain the BMS board as well.

[thesame]

It has 3 contacts also, i also mentioned that it used to work with it , i have installed now the one that you can see in the picture and it does the same thing.