Why does my ePRO+ show the wrong polarity (current is negative when charging, etc)?

If your ePRO+ is showing the wrong polarity, meaning that current is negative when charging and positive when discharging, then you have installed your shunt in the wrong direction. When installing your ePRO+, it is important that you connect the negative battery cable to the side of the shunt marked "BATTERY" and that all other negative cables go to the side of the shunt marked "SYSTEM". The image below shows where the "BATTERY" and "SYSTEM" markings can be found.