What's my car doing

[gouba 0]

Last night my car decided it wouldnt turn on, it would try and turn over and then nothing.

This morning I had my car jump started by state and the road side assist guy said my voltage was low and to take it for a drive. I drove from the CBD out to Albany (around a 30 minute drive) and turned my car off and back on again and it wouldn't start again.

My brother pulled out his volt meter and said the battery was running at around 13 volts at idle and once left off the battery was dropping voltage.

I have also found it has been harder to start in the mornings.

I'd say it was the battery, but I would have thought it would be able to start straight after a drive even if it isnt holding charge for long.

Thanks in advance

[Lucan 196]

Exact thing was happening to me.

While idling the battety voltage will be above 13V because the alternator is charging..

You'll need a new battery if it won't hold charge anyway.

I replaced my battery and had to pull fuse 28 (lighter and aerial?) because it was the cause of a parasitic drain I was having problems with.

May pay to check battery discharge while cars turned off after getting a new battery too.

Edited April 13, 2011 by Blackie

[Lucan 196]

Also, how'd you get that dye out of your mum's carpet???

[gouba 0]

I figured, ill go buy a new battery and see what happens from there.

Anyone got a suggestion for a good place to get a decent battery?

[polley 916]

Does it still crank over fine when it is not starting? Or is it cranking over slowly or not at all?

[gouba 0]

It attempts to start, you can see the fan moving as it tried to crank over. Once connected to another car via jumper leads it starts with no issue at all.

[rxstephen 0]

My brother pulled out his volt meter and said the battery was running at around 13 volts at idle and once left off the battery was dropping voltage.

Your absolutely right that the battery is not holding charge, but also with the engine running the alternator should hold the voltage closer to 14v not 13v. It may be that your battery has died because it's not getting fully charged.

Over time the battery will give up the ghost if not kept charged. When you get the new battery check the voltages again while the engine is running. If it's not up around 13.8 to 14v then you should get your alternator either repaired or replaced. Otherwise your new battery will only last a few months.

[polley 916]

I would check grounds and ouput at the alternator before just going out and buying a new battery.

[gouba 0]

Cool, thanks for this. I'll get under it this weekend and see if the connections are secure and see what the voltage is sitting at.

[325i_coupe 0]

hmmm voltage at idle was around 13.4-13.8 , after you turned the car off it would sit at about 12.4v then after it sat at work for about an hour it was down to 10.something, something draining it or its just not holding charge any more, jump start it its fine. and will keep running turn it off and try again it again and it wont, its not even trying to start just doing the good old "click click click" did think the running voltage was low but matt googled it while he was at work and said it was fine.....

FYI i'm goubas brother

[cliffdunedin 8]

What i have found is when the alternator has gone, usually it will not keep charge esp if you are using the headlights. If it's the battery it will usually need a jump to start but will hold while driving.

[hotwire 352]

It sounds very much like the battery at fault in this case.

That said - it could also be current draw. Without checking - you are only guessing.

Battery test - Hydrometer (cells even & charged) & if showing charged - load test

Current draw - ammeter in series with battery lead

[Jay 735i 0]

Battery test - Hydrometer (cells even & charged)

Can you even get unsealed batteries these days? Everything is sealed, zero-maintenance now, so this test might not even be possible.

[MGL 4]

You can get desulfated batteries from The Battery Clinic in Otahuhu cheap as, like, $40 or something, he warranties them too. I've put them them in my last three cars, never had problems since.

Its a good way of replacing them if you're a cheapskate like me!

matt

[rxstephen 0]

Can you even get unsealed batteries these days? Everything is sealed, zero-maintenance now, so this test might not even be possible.

My BMW original battery has a hydrometer built in. It's a little spy glass that goes green if the battery is good, white if OK but needs some love and attention and red if its about to quit on you.

I also make the point of using a multi stage battery charger/conditioner over night once a month to top up it. They put a full charge on the battery up to 15v then drop back to a holding voltage of 13.8. That prevents sulphation and extends the life of the battery for may years.

[hotwire 352]

Can you even get unsealed batteries these days? Everything is sealed, zero-maintenance now, so this test might not even be possible.

Yes you can - NOT all batteries are MF - by no means. Otherwise - I wouldn't have mentioned it.

And... many MF batteries have cells that can be accessed.

My BMW original battery has a hydrometer built in. It's a little spy glass that goes green if the battery is good, white if OK but needs some love and attention and red if its about to quit on you.

That is only monitoring one cell though, shows genrically the state of charge.

That cell can be charged while there is a dead one elsewhere, so pretty much a gimick & not an ideal guide.

Most MF batteries nowadays have thet sight glass

[Sick Puppy 1]

I also make the point of using a multi stage battery charger/conditioner over night once a month to top up it.

What brand do you have? I have, or rather had a CTEK (until the quake, and several inches of water/liquefaction), and am looking at other brands shortly...