Victron Phoenix 24V/2 Bank + 1Aux Battery Charger

The Victron Phoenix Battery Charger is a professional-grade, industrial-quality automatic charger designed to simultaneously charge two main 24V battery banks and maintain a third auxiliary (starter) battery — all from a single unit. Available in two output current ratings — 24/16A and 24/25A — both models feature a microprocessor-controlled adaptive four-stage charging algorithm, universal AC input, two full-rated main outputs, and one 4A trickle charge output, making them an ideal solution for marine, RV, and off-grid installations with multiple 24V battery banks.

The adaptive charging algorithm automatically optimises the charge process based on how the battery is being used. After a deep discharge the absorption time is automatically extended to ensure a full recharge. After only a shallow discharge the absorption time is kept short to prevent overcharging. BatterySafe Mode gradually raises the applied voltage to the absorption set point to protect batteries from damage due to excessive gassing during rapid charging. Storage (All Season) Mode reduces float voltage after one day of float charge to minimise water loss during long periods of inactivity, with a weekly repeated absorption cycle to keep batteries in condition.

Both main outputs (Output +1 and Output +2) share the full rated bulk charge current — meaning the total available charge current is distributed between the two banks based on their demand. The third trickle charge output delivers up to 4A continuously to maintain a starter battery or small auxiliary battery at full charge without risk of overcharging. An external Phoenix Charger Control remote panel (optional) connects via RJ45 and allows remote monitoring of charge status and temporary current limiting from up to 100 metres away.

A factory-supplied temperature sensor connects directly to the charger and mounts on a battery terminal, providing temperature-compensated charge voltage adjustment throughout the entire charge cycle. Voltage sense terminals allow the charger to compensate for DC cable voltage drop, ensuring accurate charge voltage at the battery terminals regardless of cable length or resistance. The blue aluminium IP21 enclosure is suitable for floor and wall mounting in engine rooms, battery compartments, and electrical panels.

Features

Adaptive Four-Stage Charging Algorithm

The microprocessor-controlled adaptive charging system automatically adjusts absorption time based on actual battery usage — keeping absorption short after shallow discharges to prevent overcharging, and extending it after deep discharges to ensure a complete recharge every cycle. Bulk, Absorption, Float, and Storage stages are all included.

BatterySafe Mode — Prevents Excessive Gassing

When a high absorption voltage has been set for rapid charging, BatterySafe Mode gradually increases the applied voltage to the absorption set point rather than applying it instantly — preventing battery damage from excessive gassing during the transition from bulk to absorption charging.

Storage (All Season) Mode — Reduces Battery Water Loss

After one day in float charge, the charger automatically reduces float voltage to 26.0V to minimise electrolyte water loss during long-term storage. A user-configurable repeated absorption cycle (default every 7 days, 1 hour) ensures batteries remain fully charged and sulphation-free throughout the storage period.

Two Full-Rated Main Outputs and One 4A Trickle Output

Both main battery bank outputs share the full rated bulk charge current — with distribution based on battery demand — while a dedicated third trickle charge output delivers up to 4A continuously to maintain a starter battery or small auxiliary battery. The third output uses a separate connection terminal and independent fusing.

Temperature-Compensated Charging with Voltage Sense

The included factory-fitted temperature sensor mounts to a battery terminal and continuously adjusts charge voltages based on actual battery temperature. Voltage sense terminals compensate for cable voltage drop, ensuring the battery receives the correct charge voltage regardless of cable length or resistance.

Universal AC Input — Worldwide Operation

Operates across a 90–265V AC input range at 45–65 Hz without any adjustment — maintaining full rated output current from 187V upward, with a graduated derating below 187V down to 90V minimum. The power factor correction first stage ensures a near-unity power factor (≈1) across the full input range, minimising reactive power draw on the shore supply.

Remote Panel and RS-485 Interface

An RJ45 connector on the charger accepts the optional Phoenix Charger Control remote panel — enabling remote monitoring of charge stage LEDs and temporary charge current limiting from up to 100 metres away. The same RS-485 interface allows connection to the Victron MK2-USB interface for full parameter configuration via VEConfigure software.

Aluminium IP21 Blue Enclosure — Floor and Wall Mountable

The blue aluminium RAL5012 epoxy powder-coated enclosure with IP21 protection is rated for installation in marine engine rooms, battery compartments, and electrical panels. Suitable for floor and wall mounting — vertical orientation recommended for optimum cooling. Noise level is below 45 dB(A).

Specifications

Datasheets and Manuals

Datasheet

Product Manual