- Rating ★★★★☆
- RRP £25
- Buy one at Halfords.com
OWNERS of old cars will at some point have sat in their pride and joy, and turned the key, only to hear the dreaded clunk of a reluctant starter motor. The culprit is usually the battery, which runs down over time if the car sits idle.
Even a brand new battery can run flat over a couple of weeks as vehicles draw a small amount of power even when switched off, and repeatedly being left to go flat will shorten both the battery’s working life and the owner’s temper.
The solution, as old hands will know, is to connect a maintenance charger to keep the battery topped up. However, its not always desirable or even possible to run a mains cable outside the house to keep the unit plugged in. The answer could be a solar-powered maintainer, according to Halfords.
We tested the new Halfords 2.4W Solar Battery Maintainer on a 2-litre petrol car that will, fairly reliably, drain its battery to the point that it won’t start within about 10 days. For the owner — me — it is a frequent cause of frustration.
Using the supplied suckers, the panel sticks neatly inside the windscreen but it could also lie on the dash. If the car has a permanently live 12V lighter socket it is possibly to plug in there but in cars that disconnect the socket after the car is switched off, clips can clamp directly onto the battery.
The panel is water proof so it could be fixed outside a garage or wall, where theft is not a concern.
A plug to connect via the on-board diagnostics (OBD) port can be bought separately (£10 at time of writing).
So how did it perform? Even on cloudy days the Halfords 2.4W Solar Battery Maintainer produced a good supply of free (and “green”) power, keeping the car’s battery at a healthy 12.5V or above, and after two weeks’ use the car started briskly on the first flick of the key.