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BUCKBOOST-SERIES Buck-Boost DC Converter

  • Suitable for all types of batteries
  • Buck-Boost converter can be fully programmed
  • Input voltage 10-30Vdc
  • Output voltage 2-30Vdc (12/24Vdc variable settings)
  • Current: 25A and 50A
  • Adjustable current limiter
  • Temperature monitoring
  • Automatic activation when engine running
  • LED status indicators
  • Battery monitor by means of 2 RGB LEDs
  • M8 connections
  • Output for activation/deactivation of loads
  • USB for configuration/monitoring
  • Built-in Lithium battery for low-voltage protection
  • Two converters can be connected parallel when the settings are identical

Buck-Boost DC Converter

Product Overview


Buck-Boost DC-DC Converter 25A and 50A

The Buck-Boost DC-DC Converters  from Victron Energy will charge a 12V or  24V service battery in vehicles with a smart alternator.  The converter charges the auxilliary battery with a pre-set charge voltage, eliminating  high voltages (e.g Mercedies: 15.4V) and low voltages. 

The Applications  are the controlled charging of the service battery, and the automatic activation and deactivation of electric devices in vehicles controlled by a unique engine running detection protocol (no annoying cables).

Fully Programmable  the converter can be fully programmed by means of a simple and user-friendly PC application (USB type A male to USB type B male cable needed).

One product for 12V, 24V and 12/24V systems  The converter can be fully programmed to charge a 12V or 24V auxilliary battery from either a 12V or a 24V alternator and starter battery.

Engine running detection The converter has a unique engine running detection system. This prevents the converter from discharging the starter battery if no power is being supplied by the alternator.  The converter turns ON when the engine is running and the input voltage exceeds the pre-set voltage. 

Charge current limiter The output current is determined by the following factors.

1) Setting: The maximum required change current is set via the USB connection (with the Windows Converter/Monitor application)

2) Temperature: The internal converter temperature attains the maximum termperature setting, the charge current is automatically limited so that the internatl temperature never becomes impermissibly high.

3) Input current: The maximum input current is set via the USB connection (with the WIndows ConverterMonitor application). The maximum input current setting prevents the stater battery and/or the alternator from being overloaded.  This also facilitates the choices of cable diameter and fuse.    


Buck-Boost DC Converter
Input voltage range

7 - 35V

Undervoltage shutdown


Output voltage range

2 - 30V

Maximum Charge Current

12V: 25A, 24V: 15A

12V: 50A, 24V: 25A

Power Consumption

Converter off, LEDs off

7mA (power save mode)

Converter/Monitor PC
Monitor live values

Input voltage

Output voltage and current


Set parameters

Output voltage

Maximum input and output current

Maximum Temperature

Power save mode timer

Battery levels

Motor detection settings

How the 2 input/output pins are used

PC Monitor screenshot See technical illustrations
The converter has three M8 bolt connectors for in- and output power, a two wire connector that can be useful as inputs or outputs and a USB connector to connect to a computer to configure the device


Converter input (dynamo/starting battery)


Ground (chassis)


Converter output (additional battery)

Pin 1

Input/output (purple wire)

Pin 2

Input/output (green wire)

LED Indicators
The Buck-Boost converter has two RGB LEDs

The IN LED status

Green: Converter ON, by the engine running detection system or by voltage on pin 1

Yellow: Converter OFF, the input voltage is lower than the set low voltage shut down threshold

Red: Converter Off, over temperature

Blue, quick flash: the engine running detection is active, the converter will turn ON after a delay.

Blue, slow flash: The converter is Off and activation is blocked due to low input voltage

The OUT LED status

Green: Converter OFF, battery voltage normal

Yellow: converter OFF, battery voltage low

Red: converter OFF, battery discharge or not connected

Purple: converter on


Operating Temp range

-25 to +80C

Ambient termperature

Max current up to 40C


25A: 1kg

50A: 1.1kg




Technical Illustration

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