Came to start my GS this afternoon after it's been stood for 7 months.
Battery was flat so had to jump start it.
Started and ran with no issues, ran it around town for an hour to charge the battery.
Pulled up at home, went in for a coffee.
Came out after about 20 minutes later and car was !dead! had to use key to open door, steering wheel didn't move. alarm/immobiliser LED didnt flash. NOTHING

I've checked the main fuse - visually
Pulled battery and put it on charge - my very expensive smart charger says its fully charged and in "good" condition.
Pulled ECU fuse and visually checked it, hoping an ECU reset might be needed.
Reconnected after about 90minutes.

Nothing - still dead.

the battery connections appear to be tight, so I'm a little stumped...

I'll be taking my AVOmeter to it tomorrow to electrically test the fuses/connections, but I'm hoping someone can point me straight to the fault

a side issue, which may not be relevant, considering GS started an ran for over an hour/30 miles round town. I used my van to jump start it, and I have an alternator issue with it - it's only putting out about 11V , so I have that to replace as well.
$$$$$$$$$$$$$$$

 

Seems to me you already know the problem Bad alternator and a battery dead for 7 months seems to be a good enough to keep the car dead. Replace them both and all should be good. Your charger may say the battery is fully charged, but doesnt mean it holds the charge.

 

Sorry, alternator on *the van* is bad, dunno about the car.
Suppose I'll have to hook the car up to the van again tomorrowand see if the battery is the problem, or a connection beyond that.
I'll be mildly irritated if it is the battery, as it was replaced just before the car was laid up.

As to the battery - surely if I'm getting 14V(ish) off the battery, there should be enough charge to show *some* life in the car?

 

car ran after you jumped it. alternator is cool. battery is toast. when you store it you should disconnect the battery and you have to cycle it

 

swap batteries with another car. my guess is its the battery tbh 7 months is a long time to have it sitting.

 

thanks for all the comments. I will update tomorrow when I've investigated fully.

 

Not on the GS. Maybe it varies per year, but I know mine doesnt and it was confirmed when I though it was bad and took it in to get checked. Found out it was a completely dead battery. In his case (as well as in mine recently as it happened again) if the battery holds just enough juice, then yes the alternator will sustain, but the car wont run purely on the alternator.

 

true. but it takes a lot to completely dead a battery to that point. ive had changed only 2 batteries in the gs4 since i bought it like 8 years ago. never seen a completely dead battery on it.

 

Indeed. The first time was when my GS was at the paint shop. Somehow they killed the battery like everyday and were recharging it every day till one day it blew up. It was them that put blame on the alternator. This current time was bad connection

 

not had chance to jump start the car today, but put avometer to the battery.

It's TOAST. So much for my expensive intelligent battery charger.

Been a bad week for batteries in my household - new van battery. new carbattery.
AND now I've just been informed my Xbox controller needs a new battery

 

Word of advice, start your car and run a few minutes at least once a week if you plan on letting it sit. This will keep the battery in check. At least its still new, not sure if uk is like here where the warranty will take care of it. Its only a few months old, so you may only have to pay like $20-$30 bucks replace it. BTW, a charger cant put a load hard enough to see if it will hold a charge, maybe a very expensive one, so dont think bad on the investment

 

what battery charger did you use?

 

Sealey electrosmart 300:

I paid just over £120 for it ($200?) at a bankrupcy auction, tho - not full price!

 

When a battery drains down and then sits dead, the plates in them warp and make contact. Once this happens the battery is toast and can never be restored.