Hi.... yhat cutter uses the Gen1 40 volt battery that is wired in a fairly odd manner. You can't quantify the complete voltage between any two focuses on the battery terminals. All things being equal, a completely energized battery should gauge roughly 24 volts between terminals C and + and between terminals Omega and +. Since you are just getting around 13 volts, the battery is most likely not appropriately charged. At the point when you push down the test button on the battery, the number of green LEDs do you see ? Each of the four LEDs ought to enlighten when the battery is completely energized. In the event that the two batteries won't charge, the issue could be with the charger.