Unlucky! Got hold of a battery for £34, went to take the negative terminal off and there was small spark/fizz, thought hang on it shouldn't have done that from a nudge...tried the ignition, lights on, car started normally! Did a wee bit more fiddling, the terminal is loose! But the nut has siezed so can't tighten it, but it's been fine for ages! But I did notice that it was generally looking grubby so a bit of a clean and some copper grease and seems okay so far! Took the battery back unopened for a refund, happy with that!