Flat Battery Woes

Problem

You know that sound when your car won't start - the battery manages to turn over the starter motor slowly but the engine just won't fire up. You might also hear a rapid clicking noise from the starter motor. Yes, your battery's flat and your car's going nowhere until you fix the problem.

This happened to me a few days ago, so I jump started the car and drove it around for about half an hour to charge up the battery. Problem solved - not. The following morning it wouldn't start again. The obvious suspect was the battery, but I didn't want to splash out on a new one without being sure that it was the cause of the problem.

Diagnosis

The most obvious possibility was that something was draining the battery, e.g. lights left on. After checking the visible interior and exterior lights, it was necessary to ensure that there were no lights stuck on in places like the glovebox, but how? 1) open the glovebox and note that the light comes on 2) start taking a video picture with a mobile phone or a compact digital camera. 3) Put the camera into the glovebox, close it and wait a few seconds, 4) remove the camera and watch the video. If it goes dark when the glovebox is closed, you know the light has gone out; if not - you might have found your problem. This handy little technique can be used to check lights in the boot, under the bonnet, to find out if the light goes out in your fridge, etc.

Another possibility was that the battery wasn't charging. With the engine running, the voltage across the battery terminals should be higher than when the engine is not running, so I tested this using a Multimeter from Maplin and concluded that the battery was being charged.

Perhaps the most important part of my diagnosis was the phone conversation I had with Tim from Fishers Volvo in Gloucester, who ran through a checklist of possibilities with me and confirmed that the problem was almost certainly that my battery had come to the end of its useful life - thanks Tim!

Solution - Buy a New Battery

Not wishing to pay the exorbitant prices demanded by local suppliers I looked on the internet and found a few potential suppliers. The one that looked best was Advanced Battery Supplies, who responded quickly to an email question that I asked about the vent pipe from the battery. I ordered the battery online (£65 including VAT and delivery - a significant saving on local prices) and it was delivered the following day complete with some more help about the vent pipe - great service!

KL 28th June 2010