Collection: Battery Support Units (42)

Truckstop Group stocks battery support units for HGV and commercial vehicle use. A battery support unit maintains voltage to the vehicle's electrical system during battery disconnection, diagnostic work, or extended engine-off periods — preventing module reprogramming and data loss that can result from a voltage drop. Essential in any workshop working on modern commercial vehicles with complex ECU networks. Next-day UK mainland delivery or collection from our Midlands branches.

Battery support units in the HGV workshop

Modern HGVs carry a significant number of electronic control modules — engine ECU, transmission control unit, ABS and EBS modules, tachograph, telematics, and cab comfort systems among others. Many of these modules retain data and operating parameters that are reset or corrupted if the vehicle's battery voltage drops below a threshold during a battery change or electrical repair.

A battery support unit provides a stable voltage supply to the vehicle's electrical system via the OBD port or battery terminals while the main batteries are disconnected. This maintains the module supply voltage above the reset threshold and prevents radio codes, ECU adaptations, and stored fault history from being lost during routine maintenance.

On 24V HGV systems, ensure the battery support unit you select is rated for 24V output. Most commercial vehicle battery support units are dual-voltage units that operate at both 12V and 24V. Some also provide a power supply function for extended engine-off use in a parked vehicle — for keeping telematics and refrigeration systems powered in a depot, for example.

Battery support units for workshop diagnostic use should have an output current rating sufficient to sustain the vehicle's electrical loads during diagnostic work. A unit that cuts out under load during a diagnostic session causes exactly the voltage drop it is supposed to prevent.

Frequently Asked Questions

Why do I need a battery support unit when changing a truck battery?

Modern HGV ECUs and control modules can lose programmed adaptations, radio codes, and stored diagnostic data if the supply voltage drops below approximately 9V during a battery change. A battery support unit maintains voltage to the system while the main batteries are disconnected, preventing data loss and avoiding the need for module reprogramming after the battery change.

What voltage does a truck battery support unit need to supply?

HGVs use 24V electrical systems. The battery support unit must supply 24V DC at sufficient current to maintain the vehicle's electrical load during the work being carried out. Many professional battery support units are dual-voltage, operating at 12V for cars and vans and 24V for trucks and HGVs.

Can a battery support unit also be used to jump-start a truck?

Battery support units and jump starters are different products with different designs. A support unit provides a low-current sustained voltage supply for maintenance work. A jump starter is designed to deliver a high current pulse to turn over the engine. Some heavy-duty units combine both functions, but confirm the specification before purchasing if jump-start capability is a requirement.

What is the difference between a battery support unit and a battery maintainer?

A battery maintainer is designed to connect to a battery over extended storage periods and maintain charge through a low-current float charge. A battery support unit is designed to replace the battery as a voltage source during disconnection and repair work. The two serve different purposes and should not be treated as interchangeable.