Battery woes

[Martin Butler]

Originally Posted by SD1too

For how long had your spare battery been standing since it was fully charged? As you probably know, a car battery will slowly discharge itself even when not connected to anything. Your report that the engine didn't fire immediately suggests that your spare was, in fact, partially discharged.

Regarding the first battery being only a month old, did you charge it immediately after delivery? And what use has it had since then? If it's been starting the engine frequently without being taken on a long run, that could be the explanation.

Simon

Yes i put it on charge as soon as i got it, it was only about 50 per cent charged, the old one i charged up two days before it was needed, The tester shows no weak cells, but at about 3 might even be older years, it was on the car when i bought it, it might be coming towards the end of its life, batteries do start to fail at about 4 years