Electric Skateboard: The Li-Po Battery Dissection

My Li-Po battery broke! I first noticed when I went to charge it and the intelligent battery charger only detected 7 cells rather than the 8. Looking at the balance lead lines, the battery voltage between leads 7 and 8 (reading from black/ground) read 0 volts! The worrying thing is that both leads were still electrically connected to the circuit, indicating that it not simply and loose lead or dry joint.

After pulling it apart, I confirmed my fears, the balance leads haven’t broken, one of the li-po cells is at 0V. This pretty much means it screwed. This Li-Po was a new one made by Turnigy and sold by Hobby King. It is the second time it’s ever been charged! Unimpressed! As a last ditch effort I manually tried to charge it, but no luck! The dead cell drew up current without the cell voltage increasing by any significant amount. I passed up to 1.5A through it for a few minutes with no more than 40mV on the terminals. I didn’t want to push this technique too hard for risking blowing up the cell…