Electrics: More power – Victron’s battery-to-battery charger now delivers up to 70 amps
Hauke Schmidt
· 16.06.2026
The Orion XS 12/12-70 charges a service battery from the starter battery – typically whilst the engine is running and the alternator is supplying power to the starter battery. The battery-to-battery charger precisely regulates voltage and current to charge the service battery optimally, even when the alternator is supplying only a low voltage or long cable runs cause voltage drops. With a charging current of 70 amps, the unit is suitable for larger battery banks or systems with high energy requirements.
The existing Orion XS models (12/12-50 and XS 1400) do not require a fan – they rely on passive cooling via the aluminium circuit board and the housing. The high efficiency of 98.5 per cent ensures low power dissipation, so heat generation remains moderate. However, passive cooling is no longer sufficient for the new 70-amp model. Victron has therefore fitted an external fan to actively cool the electronics.
Detecting engine shutdown, understanding the smart alternator
A key feature of this battery-to-battery charger is its automatic engine status detection: the device detects whether the engine is running or has been switched off without the need for an external sensor. As soon as the input voltage drops below a defined value (typically below 13 volts in 12-volt systems), the charger switches off. This protects the starter battery from discharging.
Four-stage charging algorithm and unlimited parallel connection
The battery-to-battery charger uses a four-stage charging algorithm (bulk, absorption, float, storage), which can be configured for different battery types: lead-acid, AGM, gel or lithium. The charging currents for input and output are adjustable in 0.1-amp increments – this protects weak alternators from overloading and allows for precise adjustment to the service battery.
Another key feature: unlimited parallel connection is possible. If you require more than 70 amps, you can connect several Orion XS units in parallel. The units synchronise automatically via the VictronConnect app or a GX unit with DVCC (Distributed Voltage and Current Control).
Still no bidirectional charging
The Orion XS 12/12-70 charges in one direction only: from the starter battery to the service battery. Bidirectional charging – i.e. charging back from the service battery to the starter battery – is not possible. This function is offered, for example, by newer battery-to-battery chargers from Sterling Power or the the latest models from Mastervolt. Bidirectional charging can be useful when the service battery is being charged via solar panels or shore power whilst the engine is not running, and the starter battery needs to be recharged at the same time. With the Orion XS, charging is strictly unidirectional.
Not quite as waterproof as it used to be
The existing Orion XS models (12/12-50 and XS 1400) are fully IP65-rated: dust-tight and protected against water jets from all directions. They can be installed in damp environments such as engine rooms without the need for additional protection.
The situation is different with the Orion XS 12/12-70: the power electronics themselves are still enclosed to IP65, but the external fan reduces the overall protection rating to IP20. IP20 means: protection against solid foreign objects larger than 12 millimetres, but no protection against water.
For marine applications, this means that the battery-to-battery charger must be installed in a location protected from direct splash water. A dry installation location is essential. For crews requiring a fanless, fully weatherproof charger, the Orion XS 12/12 remains the better choice.
Integration into the Victron system
The battery-to-battery charger communicates with the VictronConnect app (iOS/Android) via Bluetooth and can be configured and monitored through it. It also features a VE.Direct port, which enables connection to a Victron GX device (Cerbo GX, Ekrano GX). When used in conjunction with a GX device, the charger supports DVCC – the system then centrally coordinates all charging sources (solar controller, shore power charger, alternator via the Orion XS) to charge the battery optimally and safely. The Victron Orion XS 12/12-70 costs around 480 euros. By way of comparison: the 50-amp model (12/12-50) costs around 350 euros, the flexible XS 1400 model (12/24 volts, up to 58 amps) around 600 euros.
Further information is available at the Victron website.
Technical specifications:
Orion XS 12/12-70:
- Input voltage: 9–17 V
- Output voltage: 9–17 V
- Maximum charging current: 70 A (adjustable from 1 A in 0.1 A increments)
- Maximum power: 980 W
- Efficiency: up to 98.5%
- Charging algorithm: Four-stage (bulk, absorption, float, storage)
- Protection class: IP65 (electronics), IP20 (complete unit with fan)
- Cooling: Active (external fan)
- Communication: Bluetooth, VE.Direct
- Parallel connection: Unlimited possibilities
- Bidirectional charging: No
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Hauke Schmidt
Test & Technology editor
