Reverse Battery Polarity; Reverse Pv Polarity - Victron energy SmartSolar MPPT 75/10 Manual

9.2.1. Reverse battery polarity

Reverse polarity is when the positive and the negative battery cable have been accidentally swapped. The battery negative has
been connected to the positive solar charger terminal and the battery positive has been connected to the negative solar charger
terminal.
Be aware that a red cable or positive labelled cable might not necessarily mean that the cable is indeed a
positive cable. A wiring or labelling mistake could have been made during installation of the solar charger.
The solar charger is not protected against reverse battery polarity and any damage caused by this is not covered under warranty.
Reverse battery polarity will be accompanied by a blown solar charger fuse (located near the battery terminals). With a bit of luck,
just this fuse is blown, and replacing it will be the fix but it could also be that the solar has been damaged. Before replacing the
fuse, first rectify the reversed battery polarity issue. If the replacement fuse blows straight away after power to the solar charger
has been restored, the solar charger is faulty.
Always verify the battery polarity before reconnecting the battery wires to the solar charger.

9.2.2. Reverse PV polarity

In case of reverse PV voltage, the solar charger will not indicate an error. The only way to tell is by the following signs:
• The controller is not charging the batteries.
• The controller is getting hot.
• The PV voltage is very low or zero Volt.
If this is the case check for reverse polarity by ensuring that the positive PV cable is connected to the positive PV terminal, and
the negative cable is connected to the negative terminal.
Page 39
MPPT solar charger manual
VictronConnect – link to "why is the charger off"
Examples of correct and incorrect (reverse) battery polarity
Troubleshooting and Support