Install Victron Energy multi-output battery chargers – complete guide

Step-by-step instructions for correct installation, cable sizing, and configuration of Victron chargers for AGM, GEL, and Lithium batteries.

Victron Energy offers advanced multi-output battery chargers for boats and vehicles. In this guide, we explain how the outputs work, how the charging current is distributed, and how to use them optimally.

What do multiple outputs mean?

The charger's designation indicates the number of outputs, for example, Phoenix Smart IP43 Charger 12/30(3) where the number in parentheses indicates three equivalent outputs. If it says (1+1), it means two outputs with different charging currents, e.g., 27A on the main output and 3A on an auxiliary output for the starter battery.

Optimal charging for different battery types

Today's Victron chargers can be configured for different battery types such as AGM, GEL, or Lithium. This provides maximum charging efficiency and extends battery life.

How multi-output chargers work

• All outputs have the same charging characteristic – if the charger is set to AGM, all outputs are charged with AGM settings.
• For (1+1) type chargers, the distribution is predefined, e.g., 27A + 3A. Check the datasheet for your model.
• For (3) type chargers, the distribution is dynamic – the battery bank that is most discharged receives the most current. If you only connect one output, all charging current goes there.
• It is also possible to connect multiple outputs to the same battery to increase cable area and reduce voltage drop.

NOTE! Do not charge two different battery types with the same charger – instead, use multiple chargers or a DC/DC charger for separate banks.

Smart control and monitoring

Victron Energy Smart chargers are controlled via the Victron Connect app. For calculating cable dimensions, you can use the Victron Toolkit, which we describe in our blog: Which cable dimension should you use?