Tried and tested: Healtech Thunderbox review

Healtech Thunderbox
Healtech Thunderbox

One of the issues if you run a collection of electrical accessories – sat-nav, heated kit, phone charger, spotlights – is remembering to turn it all off when you get to your destination and hop off the bike. However there’s a device called the Healtech Thunderbox that helps out in this situation.

While some will go with you, heated gloves, for example, some may stay on the bike. These devices could slowly drain the battery, leaving it dead when you come back to it.

While some riders fit auxiliary fuseboxes that can be powered by relays or directly from the battery, the Healtech Thunderbox is a handy device that does away with all that. It will supply power to your gadgets only when the engine is running and charging the bike’s battery.

There are two versions available: one with a total capacity of 16 amps over four outputs (TB-U01) and one with a capacity of 32 amps over eight outputs (TB-U02). Both work on the same principle; the Thunderbox connects to the bike’s battery and remains ‘closed’, i.e. it does not send power to its outputs until it reads a voltage across the battery terminals of 14.4 volts, i.e. the engine is running and charging the battery.

Once the engine is shut off and the voltage drops to the usual resting 12.8V, or thereabouts, the unit switches its outputs off to prevent any connected accessory from draining the battery.

There is an LED lamp on the body to indicate its status, and there is also a third input wire that can be connected to an ignition-switched live, so the unit powers up as soon as the ignition is turned on instead of when it registers the battery charging or if connected to the black (earth) connector, to render the unit inert.

Stripped wires ready for connection to Healtech Thunderbox

The Thunderbox also has built-in overload and short-circuit protection, so that the accessories don’t have to have separate fuses installed (though many will prefer to keep them for extra protection).

If an overload or short circuit occurs, the unit will automatically disconnect the power and then re-connect it. If this happens three times, it will effectively shut the power off to the accessories until the problem is resolved and it is reset (disconnected from the battery for five seconds).

There are two connectors on the 16A version – one live and one earth – and four on the 32A (two of each) and they are very easy to use, though they do need accessory cables to have any pre-fitted terminals removed and wires stripped bare. Sprung-loaded clips hold the wiring in place, with banks of four live connections and four earth connections.

Wires connected to Healtech Thunderbox block

In use, it’s very easy; connect to the battery and forget all about it. When you fit a new accessory, simply connect to the plugs and you’re ready to go. Firing the engine up, the Thunderbox takes a handful of seconds before it kicks in and activates your accessories. It takes a little longer after turning the engine off until devices are disconnected.

Related: Top electronic motorcycle gadgets and diagnostics

Not once has it failed to power up or down and I know with it in place, the bike’s battery will always be ready to start the engine, and all accessories and wiring will be protected.


This is an easy way to wire accessories to the bike’s battery while ensuring that it will never get drained if you inadvertently leave them on. The in-built protection is also useful, as some devices can come without inline fuses and this will offer protection in that case.

Healtech Thunderbox tucked away near motorcycle battery

It does mean you need to chop-off ring terminals when supplied, but if you are moving accessories from one bike to another, it’s no hardship to either refit terminals or just move the Thunderbox wholesale, with connections intact. Easy.


  • Ensures accessories only run when battery is being charged by the engine
  • Provides built-in overload or short-circuit protection
  • Available in two capacities – 16A and 32A


  • Means you need to chop off pre-fitted terminals on accessory wiring

Electronic motorcycle accessories:

Rrp: £299.95

Price: £249.69

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