It only has 2 balance wires, number 1 & 2, GND & 3 are jumpers from the battery connection pads, but the negative battery connection goes via the ground tab to the top left ground point on the board and the positive is wired. So as I said above there is a possibility the GND balance connection is higher resistance and why I asked if it is common that cell1 is the low one.[/QUOTE] Sorry Vaping, i'm not so "technical", does it mean that i have to send it back (if Wismec reply me) or i can do something to fix it by myself?