wont hold charge

[jakeufton]

hi my nova just wont hold charge, i charge the battery up and its fine until i leave it for about 6-7 hours then completly dead, ive had a new battery and full service and once over but nothing found, any help rep given thanks jake

[Mazz]

Was it a brand new battery? Have you checked the that alternator is throwing out enough voltage..?

[mowgli]

does the battery hold charge when its off the car????
if no then the battery is a dud,

if yes its probably the alternator backfeeding, or are you running an amp???

disconnect the alternator wires & see if it lasts...... if it does, then disconnect any ice you have & try it again.

[Jon_nova1]

why not just disconnect the battery with the engine running and if it cuts out its a problem with the charging circuit? lol

[jakeufton]

brnad new battery and it aint the battery as had the same problem with my old one thats why i changed it lol and ill have alook into it guys thanks, not too good with cars. is the alternator like the dyno on a bike for the lights? cuz i can jump it straight away, but leave it off and it just dies! i also have no ice just head unit!

[Mazz]

Sounds like the alternator isn't charging the battery

[Mike]

alternators dead chap

[MattBrown]

No, sounds like something is pulling it down to earth, you couldnt drive for 7 hours on one charge.

Just leave the earth strap nipped, and every time you pull over pop it off.

I have a similar problem with mine.

[jakeufton]

sorry matt i dont follow? if i were to change the alternator then would this solve my battery charging woes? but sureley without a working alternator the car wouldnt turn over? i mean after i jumped it then i could turn the car off and back on again no probs, it just goes dead after trying to turn it back on after several hours:( , thanks guys your info is much appreciated

[Lee]

No, sounds like something is pulling it down to earth, you couldnt drive for 7 hours on one charge.

Just leave the earth strap nipped, and every time you pull over pop it off.

I have a similar problem with mine.

Agreed, if it was an Alt problem, the battery wouldn't die overnight, it would die during driving.

As Matt said, something in your car is dropping an earth. On my blue one, it was something in the fuel pump circuit, as it would do exactly the same, but if I removed the fuel pump relay it was fine. Unless you pull a different relay every night and see if it stops the problem, you probably wont have much luck finding what's doing it unfortunately.

As Mowgli suggested, have you got a load of ICE in the car? as id check DIY electrics before the OE stuff.

[Connor]

I had a similar problem the other week,
and it was due to a not so good alternator (charged at 12.8v)
and also the earth cable (original) on my battery was corroded where it bolts into the bulkhead, and also an amplifier which wasn't actually powering anything was draining the charge overnight so removed that and had no problems since,

[mowgli]

Agreed, if it was an Alt problem, the battery wouldn't die overnight, it would die during driving.

As Matt said, something in your car is dropping an earth. On my blue one, it was something in the fuel pump circuit, as it would do exactly the same, but if I removed the fuel pump relay it was fine. Unless you pull a different relay every night and see if it stops the problem, you probably wont have much luck finding what's doing it unfortunately.

As Mowgli suggested, have you got a load of ICE in the car? as id check DIY electrics before the OE stuff.

the regulator circuit can drain current back to earth.

another good thing to check...the charge light on the dash...

if it isn't coming on at all, then check the bulb. if the bulb is ok, then the alt is shot...
if it is permanently on, then it isn't charging

[Stuart]

so what if a battery just drops its charge... Went to town in the astra, stopped to drop off a dvd, back in and drove home. No alternator light on during the drive. Park up at home and try to start is 20mins later, nothing.

battery light comes on with the ign.

its a 10year old battery, can this just happen?

[mowgli]

yes

[jakeufton]

well i took it to my local garage today and its been there 3 days and every time the bloke goes to start it he says it starts perfect! i only jumped it and drove it bout 1mile then its been perfect since its been at the gargae! any help?! thnks

[mowgli]

he probably found a loose connection & is playing mind games on you

[jakeufton]

probably, novas are more stress than kids, relationships, infact everything! think im just going to change the alternator and take it from there... thanks guys

[John]

Did the garage check the alternator output?

[brucer]

get a voltmeter and check the charging from the alternator, should be between 13.7v to 14.4v. either check it at the battery positive to negative or from the alternator positive to any earth around. idealy check both as you can make sure the charge from the alternator is getting to the battery.

if thats good, then disconnect the earth strap and connect a multimeter between the earth strap and the battery neg terminal, have the multi meter set on amps and see if you have a drain. if this is still relatively small (around 0.1amps or less), then open a door to activate the interior light and the multi meter value should change and go back down once the door is closed.

if its fairly high with nothing activated in the car then you have a drain, this is what you will have to find to sort your problem.

[MattBrown]

Be extremely careful running a metre on amps, it can be dangerous!

[jakeufton]

i now find that if i turn the cd player off manually before turning the car off the car does not die, the alternator is checked and fine btw, still doesnt explain why the battery goes completly dead after bout an hour?:(

[mowgli]

my dad has an old fashioned way of finding electrical faults.. he undoes the positive terminal and puts it onto a rag. he sticks a test light across from the battery to the pos terminal & starts pulling out fuses until the light goes out.. then he knows where the fault lies. its stood him well over the years..

[Lee]

Good tip that!