Victron installation motorhome

Updated - October 28, 2025

The following is an example of a Victron installation in a motorhome. The circuit diagram is photorealistic to make it clearer and easier for laypeople to understand.

This installation example assumes a 200W PV system with 200 Ah LiFePo4 batteries with integrated BMS and a 1,200 VA inverter. A larger installation with 1,150 W PV, 1,120 Ah LiFePo4, 400 W external BMS and 1,200 VA inverter is here described.

Components

The components shown, such as residual current devices, fuses and batteries, are for illustration purposes only. Manufacturers, data and Cable cross-sections must be adapted to your own requirements.

Short distances

The shortest cable routes and large cross-sections are particularly important when connecting the batteries to each other and the charging booster and inverter to the auxiliary battery. All connections must be made using proper crimp connections.

Wire end ferrules are to be used for screw connections, tubular cable lugs for battery connections.

230V wiring in the motorhome is 2.5 mm² rubber cable, the wire ends of which must be fitted with wire end ferrules.

How it works

Power generation via PV modules

When there is sufficient sunlight, the MPPT controller switches the power supply from the solar panels to the auxiliary batteries and charges them.

Power generation via DCDC converter and alternator

While driving, the alternator generates energy to charge the starter battery and supply the vehicle systems, and, if there are power reserves, to feed this energy into the DCDC converter. This compensates for possible line losses and ensures that the voltage is adjusted according to the charging characteristics of the connected battery type. In this way, the charging energy from the alternator can be used for the auxiliary batteries while driving - in addition to the PV modules.

Power generation by charger

If, as is the case in most cases, the body (LiFEPo4) and starter batteries (AGM) are of different types, a separate charger is required for each type when using shore power, unless only the body battery(ies) are to be charged. Therefore, two chargers are integrated in the circuit diagram.

The charger connected to the external 230V CEE plug, after the residual current device and fuse box installed on board, supplies the starter battery with its AGM-typical charging characteristics on the output side, while the on-board charger supplies the on-board battery with the charging characteristics for LiFePo4 batteries.

Inverter

The inverter is used to supply 230V AC consumers when shore power is not available.

The chargers can of course also be used, especially for the starter battery. If, contrary to expectations, the chargers have run out of power overnight - for no reason at all, of course - you have an emergency solution on board and, if there is still enough capacity in the auxiliary batteries, you can at least recharge the starter battery using the inverter and charger.

It is understandable that you cannot charge the on-board batteries using the on-board charger by plugging its 230V plug into the inverter socket: the energy required would be higher (due to the converter losses) than the energy ultimately fed in. In other words, the on-board battery would not be charged, but discharged.

circuit diagram

parts list

The universal parts list therefore includes, apart from the PV modules, batteries and fuses, such as connection sockets/cables:

• 1x MPPT controller
  The MPPT controller must be designed according to the total power of the PV modules and for the maximum voltage applied, e.g. Victron SmartSolar 75 ... 250 V at 10 ... 100 A
• 1x charge booster
  The charging booster must be selected according to the capacity of the alternator, e.g. Victron TR Smart 15 / 17 / 30A
• 1x inverter
  The inverter must correspond to the voltage of the surface-mounted battery (12 .. 48 V DC) and its maximum power output must be adapted to the given capacity of the surface-mounted batteries, e.g. Victron VE.Direct 250 ... 1,600 VA, or Victron MultiPlus (II) 800 ... 5,000 VA, or 3,000 ... 15,000 VA
• 1x 230 V AC charger (Construction-battery), e.g. Victron Blue Smart IP 22 Charger
• 1x 230 V AC charger (Starter-battery), e.g. Victron Blue Smart IP 22 Charger

Prices are deliberately not stated, as experience has shown that they fluctuate and may therefore no longer be up to date at the time you read this article. Price comparison portals provide up-to-date price information.

- Attention -

All electrical installation work must be carried out by qualified personnel in compliance with applicable regulations. When working on electrical installations, they must always be kept safely disconnected from the power supply!
To inform uninvolved third parties, appropriate information signs must be attached to the shutdown devices during the work.
The above information is intended as a suggestion and makes no claim to completeness, compliance with relevant regulations, standards, etc.. Any liability is excluded.