Victron 20A 24V→12V DC Multi-Stage Battery-to-Battery Charger | 4Boats

Compact isolated DC‑to‑DC charger for charging a 12 V battery bank from a 24 V source; multi‑stage, Bluetooth‑configurable and designed for vehicle and marine use.

• Function: automatically charges one 12 V battery or battery bank from a 24 V battery/bank (e.g. engine starter or solar‑charged bank) at up to 20 A using intelligent multi‑stage charging and full overcharge protection. Identical units may be connected in parallel to increase output for larger systems.
• Bluetooth connectivity: inbuilt Bluetooth lets you monitor charging and change settings via the VictronConnect app without accessing the installation location.
• Safe unattended charging: built‑in protections against overload, overtemperature and reverse polarity ensure secure operation.
• Continued charging during battery/load use: the charger will continue to operate at full power while energy is drawn from the target battery or load.
• Compatibility with other charging sources: suppression filter allows safe parallel charging from alternator, solar or mains charge controllers.
• Remote on/off control: switch on/off with a hard‑wired switch, external relay or via the VictronConnect app; allows integration with vehicle battery management systems.
• Vehicle battery optimisation: compatible with smart alternators and designed to protect vehicle alternators while optimising charging.
• Galvanic isolation: input, output and case are isolated up to 200 Vdc to prevent stray currents into metal boat hulls and other conductive structures.
• Additional features: LED indicators show target battery charging status.
• Technical specifications: Input voltage 16–35 V; output current 0–20 A; max power output 280 W (25°C) / 240 W (high temp); under‑voltage shutdown 14 V; under‑voltage restart 15 V; output voltage adjustable 10–15 V (12.2 V nominal); output tolerance ±0.2 V; output noise 2 mV RMS; no‑load consumption <100 mA; standby <1 mA; max cable cross‑section 16 mm² (AWG 6); dimensions 125 x 186 x 70 mm (4.9 x 7.3 x 2.8 in); weight 1.3 kg (2.9 lb); humidity max 95% RH, no condensation.

Suitable for 12 V and 24 V lead‑acid or lithium batteries. Supplied with a 5‑year manufacturer warranty; user manual and data sheet (VOS2412‑20I) available for download.