help please

[pikey1986]

since buying my car off me neighbour a minor annoyence has become a major headache, before i bought the astra(1.7td vaux engine) i noticed that when ever she went to start it it seem to turn over really slow as if the battery was dieing but it would always fire up, its been like this for a long time so i can rule out the alternator as i have no battery light that comes on,
now this morning after i finshed work i went to start it and it only turned over 3/4 times and it died, with the help of some jump leads it fired right up and i came home, like a boob i forgot to check the battery with me volt-meter, then i went to go shop earlier and checked the battery it read 12.27/28 and it did the same thing turned over 2/3 times and died,
my questions are-(1) what should the battery be putting out with the engine running/off? (2) if my battery is shot what do you lot reccommend? (3) could this be a related to another problem?

any help/advise would be great and could result in man love

[daleNOVAbrennan]

think the battery should read 12 - 14, not 100% though. if the battery is shot, time for a new one, as it swelled over the cold weather? but first make sure all earths are good and there is nothing draining it like stereo, alarm

[eightvalver]

Sounds like a knackered battery. Should put out a minimum of 12V and between 13.5 - 14.8 (ish) when running. The batt warning light will tend to come on if the alternator is not putting out a charge, so you may be right to rule that out.

Alternators have a hard time trying to charge up a weak batt

Short term, try and charge the battery overnight and see if that helps.

[burgo]

dodgy earth ;). make a new gearbox earth strap

[Derick-Sport]

same happend on my 1.5td novavan, earth lead from the gearbox to chassis leg