Dodgy 12v battery?

[demag]

Well the car is running great after nearly three months of ownership. On this tankful of fuel I've done 315 miles and it's still showing half full so I'm still well impressed. My son likes it so much he's gone to look at a Lexus hybrid today.😊

The only concern I have is the 12v Battery. Last week we went abroad, when we got back my mpg information on the multifunction display had all reset to zero. We always leave the car at airparks and I know they will jumpstart a car if the Battery is down to move it from the secure compound to the collection area. Also when I originally bought the car the garage had to jump it to start it up. Although I know it had stood a long time

Recently every time I use the car the engine will fire up for a few minutes even in the warm weather. The diagnostic test on the hidden screen showed the Battery voltage to be over 12v but dropping under 12v on load. With the engine running it was charging OK. Does this sound like a dying 12v battery? If so I'll replace it.

Thanks.

[kithmo]

It's probably not the original Battery, the car being 12 years old, but if it's more than 4 years old I'd change it anyway. Letting the Battery stand flat as the garage did doesn't do it any good and the older the Battery is, the less chance of it recovering. If the battery is in good condition then leaving it parked for a couple of weeks when you went on holiday shouldn't have been a problem. I would put the battery on a battery charger/conditioner like the Ctek Mxs 3.8 and see if that improves things.

[drives]

Did you do the diagnostic after the car had sat overnight? If so the Battery sounds ok? Ive just replaced mine , as it was reading just   under 11v, as preventative maintenance but wasnt having any issues 

[demag]

It cut out today at some lights so I've ordered a genuine Battery, will be here tomorrow.