The Victron Energy 100A Buck-Boost DC/DC Converter is a non-isolated converter for mobile, marine and off-grid systems that need a stable output voltage from an input that varies or does not match the load. It suits dual-battery setups, vehicle-to-load charging and any installation where the input can sit above, below or equal to the output.

Key features

• Output current, 100A continuous, for high-demand DC loads and battery charging.
• Buck-boost topology, output voltage can be set higher, lower or equal to the input, unlike a simple buck or boost converter.
• Non-isolated design, efficient conversion with minimal heat loss compared to transformer-based alternatives.
• VE.Direct interface, connects to GX devices or VictronConnect for monitoring and configuration.
• System voltage, suits 12V and 24V architectures.
• Housing, aluminium enclosure weighing 4.1 kg, for permanent installation in vehicles, vessels and fixed enclosures.

How it works

A standard DC-DC converter can only step voltage in one direction. This buck-boost unit regulates the output to a fixed target whether the input sits above or below it, which matters when a starter battery sags under load or an auxiliary lithium bank rests at a higher voltage than a lead-acid one. At 100A, it can handle substantial charging currents or supply DC loads directly. The negative rails are shared between input and output, standard for most vehicle and marine wiring, so installers should confirm this suits the earthing arrangement before fitting it.

Connected to a GX device such as a Cerbo GX via VE.Direct, the converter shows up in the system overview alongside other Victron equipment. Configuration and firmware updates run through the VictronConnect app.

Applications

• Dual-battery charging in campervans, motorhomes and HGVs from the alternator.
• Marine systems needing a regulated DC supply to a secondary bank at a different voltage from the house bank.
• Off-grid cabins and mobile power systems with variable input voltage.
• Vehicle-mounted equipment needing a fixed DC voltage independent of chassis battery state.
• Renewable systems combining solar and alternator inputs across mixed battery chemistries.

Installation notes

Fitting should be done by a qualified electrician or experienced system integrator. Because input and output negative terminals are common, check this against the earthing scheme of the vessel or vehicle first. Follow applicable NMEA or flag-state wiring standards on boats, provide adequate ventilation or heatsinking for the rated current, and fuse both input and output cables close to the source in line with the cable ratings used.

What's in the box

• 1x Victron Energy 100A Buck-Boost DC/DC Converter (ORI303100000)