As the cranking speed of my 1959 Austin Healey's starter was getting very low, I drove round to Halfords and asked them to test the battery. Their meter said ‘battery unserviceable', so I shelled out £75 for a new one. This made no difference, so I replaced the starter motor with a spare I had in the garage. Starting was now instant. Meanwhile (while I was restoring the spare starter motor), the old battery sat uncharged in the garage for a month, and never dropped below 12.56v. I took it back to Halfords and asked them to test it again. It still came up ‘unserviceable', which was not true because the problem was the starter motor. The staff declined to offer any compensation.

I asked them what the meter was actually testing, but they had no idea. One of them said it tested each cell, which it could not do as the cells are connected in series. So I put the old battery back in the car and checked the voltage drop on cranking. It dropped to 10.6v, when an acceptable figure would be 9.6v. Obviously it was in rude health. So I emailed Halfords' customer services with the story, including the magic words ‘Trading Standards'. Within 24 hours they had refunded the £75 and given me a £10 voucher for my trouble. The engine continues to start instantly on the old battery. As usual, the moral of the story is ‘caveat emptor'.