Battery chargers 12V to 220V

A 12V battery charger connected to the 220V mains supply is what keeps the battery bank in good working order when there is no sun or alternator: in a motorhome plugged into a campsite, on a boat in port, or in any setting that requires a backup charging source.

How many amperes do I need?

As a general guide, the charger current should be between 10 and 20 % of the battery bank’s capacity. For a 100 Ah battery, a charger of 10 to 20 A; for 200 Ah, between 20 and 30 A.
Undercharging means spending whole nights plugged in without the battery ever fully charging. Overcharging doesn’t damage a lithium battery — it can handle high currents — but it does make the equipment unnecessarily expensive, and in lead-acid batteries it can cause overheating. If your battery bank is lithium and you have limited time connected to the mains, then it’s definitely worth increasing the amperage.

220V to 12V charger for motorhomes

In a van, the mains charger works alongside the other two power sources: the MPPT solar controller and the DC-DC booster from the alternator. All three can be connected to the same power supply provided they are set to the same load profile.
For use in a vehicle, you’ll need a charger with a high IP rating: there’s vibration, damp and dust. The Victron Blue Smart IP65 and IP67 models are designed precisely for this purpose, whilst the IP22 models are intended for permanent installation in a cabinet.

Lithium or lead: the charging profile is not the same

A LiFePO4 battery and an AGM battery require different absorption and float voltages. Charging a lithium battery using a lead-acid profile won’t cause any immediate damage, but it leaves the battery bank not fully charged and shortens its lifespan. Every charger we sell allows you to select the charging profile, and Victron Blue Smart chargers let you do this via your mobile phone using Bluetooth.
If you have 12V lithium batteries, also check that the charger has a recovery function for deeply discharged lithium batteries: not all of them will start up if the BMS has cut them off.

What else to watch

Multiple outputs if you also need to power the starter battery, a timer or a programme for off-peak charging, and a temperature sensor to adjust the voltage in winter and summer.
We also have 24V chargers y 48V. Tell us the capacity of your battery and its chemistry, and we’ll tell you the correct amperage. Free advice and dispatch within 24–48 hours.