Camper inverter or battery charger faulty? Here's how to tackle it

It's a familiar scenario: you're in a beautiful spot, you plug the camper into the mains and... nothing. Or the leisure battery isn't charging even though you're connected to the mains. The culprit is often the inverter or the battery charger, but before you rush off to a specialist, it's worth checking a few things yourself.

First, the difference: inverter versus battery charger

An inverter converts 12V DC from the leisure battery into 230V AC for your sockets. A battery charger does the opposite: it charges the leisure battery when you connect external 230V. Some campers have a combined unit or an EBL (Elektroblock) that manages both functions. So know which unit you have, because the symptoms and checks differ.

Inverter cuts out or doesn't provide 230V

Does the inverter switch off or fail to start? Then check the following:

• Battery voltage: Measure the voltage on the leisure battery. If it's below about 10.5V, the inverter switches off as a safety measure. Charge the battery first or check if the solar panel is providing enough power.
• Overload: Too many appliances connected at once? The inverter has a maximum power rating, often 300W to 2000W. Switch off heavy consumers and try again.
• Fuses: There are fuses both on the inverter itself and in the 12V supply line. A blown fuse is a classic. Only replace with the same type and rating.
• Earth connection: A poor earth (negative) connection from the inverter to the chassis can cause strange faults. Disconnect the connection, clean the contact point to bare metal, and tighten everything securely.

Battery charger not charging or charging too slowly

If the leisure battery isn't charging while you're connected to 230V, look at these points:

• 230V supply to the charger: Check that there's power at the charger. Sometimes the plug in the camper has come loose or the residual current device has tripped.
• Charger fuse: Many chargers have their own fuse on the output or input. Consult the manual for its location.
• Measure charging voltage: Use a multimeter to measure the voltage across the battery terminals while the charger is on. A healthy charger usually gives between 13.8V and 14.4V. If the voltage stays below 13V, the charger may be faulty.
• Connections and cables: Corrosion on the battery terminals or a loose cable can significantly limit the charging current. Clean the terminals and tighten everything.

If you can't find the problem or the measurements point to a faulty internal component, repair is often possible but not always cost-effective. The cost of a new inverter or charger varies widely, depending on power and brand. Sometimes a second-hand or reconditioned unit is an affordable alternative.