Mains charging

If you spend time on campsites with electric hookup, or you charge your leisure battery at home before a trip, a mains charger is the simplest and most reliable way to top up your battery. It plugs into a standard 230v socket and does the work automatically.

What a mains charger does

A smart mains charger delivers power in controlled stages — known as multi-stage charging. It pushes in as much current as the battery can safely take until it reaches around 80%, then slows down to bring it to 100% without stressing the cells, then drops to a low maintenance voltage to keep it topped up. You can leave it connected and it will look after itself.

Choosing the right charger for your battery

This is the most important decision. Mains chargers are not universal — different battery chemistries require different charge profiles, and using the wrong one causes real problems.

• Charging a lithium battery on a wet lead or AGM profile will result in a slow, incomplete charge. The battery will never reach full capacity.
• Charging a wet lead-acid battery on a lithium profile is dangerous and risks damaging the battery or worse.

Some chargers can be configured to switch between profiles, which makes them a flexible long-term investment if you plan to upgrade your battery type in the future. If your charger is fixed to a single profile, make sure it matches your battery chemistry before connecting it.

Sizing it right

Match the charger output to the battery size. A rough guide is 10 to 20% of the battery's capacity:

• 100Ah battery: 10 to 20A charger
• 200Ah battery: 20 to 40A charger
• 400Ah battery: 40 to 80A charger

A bigger charger means a faster charge, which matters if you are on a short campsite stay and want to make the most of the hookup time.