Electrical/Battery Problem
Discussion
Had my first breakdown in the VX220 yesterday,and was after some advice. Car started fine, maybe a touch slow in cranking over, but it hadn't been started for a few weeks. I was driving for about 30 mins with a stop for petrol in between when I had to stop again to pick someone up. When I tried to start again, it wouldn't! Sounded like a flat battery, hardly cranking over at all, with the alarm turning itself on after trying to start. Called out the AA, who got it going straight away with a jump start pack, and then checked the voltage which he said was spot on, so was diagnosed as a duff battery. Been out today and got a new one, went to fit it and thought I'd just try to start the car before I swapped them, and it started!
Have put the new battery on anyway(nasty job), went and got the old battery tested the following day, and although it was only reading 11v, they said it didn't show signs of a dead cell. I have charged it up, which went fine on the Optimate, and it has held it's charge over the last 3 days okay(13v straight off charge, down to 12.5v after), just sitting there not connected to anything.
Does this mean that I might have an electrical fault elsewhere, a bad earth, or could a faulty battery work intermittently?
Have put the new battery on anyway(nasty job), went and got the old battery tested the following day, and although it was only reading 11v, they said it didn't show signs of a dead cell. I have charged it up, which went fine on the Optimate, and it has held it's charge over the last 3 days okay(13v straight off charge, down to 12.5v after), just sitting there not connected to anything.
Does this mean that I might have an electrical fault elsewhere, a bad earth, or could a faulty battery work intermittently?
I find it hard to understand how if the charging circuit is working properly, which is presumably what the AA man meant by the voltage, how any battery could be worse after a 30 minute run than immediately after being left sat for a few weeks. You'd expect a run to at least put enough charge into it for a few starts even if it's not a very good battery. I'd check your charging voltage again. Usually about 14v or a bit more.
Pumaracing said:
I find it hard to understand how if the charging circuit is working properly, which is presumably what the AA man meant by the voltage, how any battery could be worse after a 30 minute run than immediately after being left sat for a few weeks. You'd expect a run to at least put enough charge into it for a few starts even if it's not a very good battery. I'd check your charging voltage again. Usually about 14v or a bit more.
Yep, the AA man meant the charging voltage. He measured it, then got me to turn the headlights on to see if it dropped, which it didn't apparently.Pumaracing said:
I find it hard to understand how if the charging circuit is working properly, which is presumably what the AA man meant by the voltage, how any battery could be worse after a 30 minute run than immediately after being left sat for a few weeks. You'd expect a run to at least put enough charge into it for a few starts even if it's not a very good battery. I'd check your charging voltage again. Usually about 14v or a bit more.
Check the connections between alternator and battery for corrosion. What is the ratio between distance run, number of starts and time between starts? It can take a while for an alternator to top-up a battery especially if the vehicle is being used on short trips (engine often at low rpm / idling) with high electrical load (heater blower, wipers, headlights).When it didn't start, it had had a 30min run with headlights, stereo on, including a stop for petrol. After the AA got it started again, it was a straight 30 min run home without stopping, again with headlights on. Then left overnight before I tried it again just before putting the new battery in.
stevieturbo said:
Could be a bad earth or connection somewhere.
this... i had some strange issues when I was overseas in my Noble a few years back, struggled to start, lost its charge but seemed fine when tested... turned out to simple be a loose connection on the earth... once located didn't have another tissue 
Bit of an update, after leaving the battery unconnected after charging, it is gradually dropping its voltage. After taking it off charge at the end of Feb and it being 12.5v, it has now dropped to 12.35v. Seems to be losing about 0.01v a day, so hoping it was a duff battery after all.
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