Hey there, i've noticed over the past month or so my battery hardly lasts,
for eg, i had just came back from a 3hr drive (from the country), when igot home to clean my car i had al lthe doors open..for 30min, then as i went to start it, the battery is dead..
I have an Optima Battery which is apparnlty very very good?,
why could my battery be dieing so quick?

(btw alternator died 2weeks ago, but was replaced so that cn't be the problem), could the battery be damadged from the alternator dieing one night?
Any info would help heaps as i can't stand starting my car to a flat battery

cheers
- Ash

(btw, its a 96 fairlane)

Get A Multimeter on the terminals when the engine is running and check to see if the Alternator is charging the Battery. Sounds like its not.

And yes its possable the optima Battery has been damaged by massive over charging.
I would suggest a external battery charge overnight (8 Hours) and then see how it goes.

It wouldnt be a bad idea to perform a static batery drain test.
To Perform this. Get a Multimeter with a Amps range of at least 10 Amps. Remove the negative battery terminal and connect the multimeter inbetween and see how much current your car is drawing with the key out of the ignation.

Then Cross referance your Battery Amp Hour Rating.

If its drawing 10Amps static and you have a 20AH Batery with a reserve Capacaty of 110 Mins. Then you battery can provide 20 Amps a hour for 1hour 50mins roughly.

However if your cars sucking say 40amps. Then you have a standyby time of 55 Mins.

did the alternator stop charging or overcharge?

Try taking your battery and getting it charged. Its what RACQ recommenede for me.

wow thanks for the long info, i'll do that asap,
yeah the altenator stopped charging as one night i noticed it,
volt meter was really really low while i was driving...
so replaced it n it charges fine (well i think so as the volt meter is way up a tad more than half way)

But it could possibly be the battery thats stuffed,
as i can't even have music playing for a bit, let alone interior lights on for 30min while vaccuming my car

- Ash

If it stopped charging nd went flat the car is not cabable of giving a proper charge. A trickle charge is needed to to bring the electrolyte specific gravity up to where it needs to be. Engine charge can only surface charge the battery.
Unfortunatly thats chemistry in action.

Happened once again this morning, went to drive off to work..sure enough a flat baterrry

haha wow that is a bit of chemistry, luck i did it in year 11 n 12 to understand what your talking about....hehe
but mechanically wise should i buy a new battery? or is it a fault with the ccar not charging properly?

If it comes down to buying a new battery, what do you guys recommend for a ford? along with a mono block, 2 subs and 4channel?

thanks
- Ash

G'day Ash.

When it comes to batteries, I've always used RAA ones. They're not hugely priced and they all carry excellent guarantees, some up to 36 months. Here's the link if you'd like more info:

http://www.raa.net/page.asp?SecID=77

On top of that, if you're an RAA member, there are further benefits.

Just as a thought, have you considered installing a Voltmeter in your car? These are really handy to have for this sort of thing. Their use is two-fold:

1) When you click the key over one notch (without starting the engine), the meter will show you the "raw" voltage of the battery, which should (ideally) be at 12V. If it's substantially less, you know your battery hasn't held it's charge.

2) When the car is running, the meter will show you the charging voltage flowing into the battery, which is normally at about 13.8V -> 14V.

Voltmeter's aren't too difficult to install, and are pretty cheap to pick up as well. Typical Cobalt / Autometer voltmeters go for about $80 - $100.

Hope this helps.

Last edited by vertg0 on Mon Dec 03, 2007 12:44 pm, edited 1 time in total.

If your alternater wasnt charging your battery properly it can sigificantly shorten the lifespan of your battery. With car running just check with a multimeter with all acesseries on what your state of charge is. This will identify if the new altternator is putting out suffiecient charge for the battery. I would by an exide battery with a high cca capacity for when car is off and you may have stereo etc running. never buy racv or nrma or whatever from your state as they are now made in korea and are cheap rubbish. Racv state they are better than last ones but i doubt it. They charge $140 and only carry two year warranties and will try to get out of this as cheap as possible. Had the misfortune of having this happen to me. Good luck

Thanks for the info guys,
Yeah my amps have a rough volt meter(when i attempted to start my car this morning [not starting]), i then check the voltage with a Multi Meter, read 11.9 volts,
the only way to TRY and revive the battery is to keep it on charge over night yeah?
So if it comes down to buying a new battery, what wouldyou guys recommened for some one like me who wants to play loud music with/without the engine on?
thanks again
-Ash

I don't think that is quite right, AH and RC are different methods of measuring the same thing.

A 20AH battery will supply 20Amps for 1 hour (or 10Amps for 2 hours). The problem with this measurement is that discharge rates don't scale perfectly (you might only get 1.9hours at 10Amps). Because of this manufacturers will adjust the load so as to give the best rating, they may test the battery with a 1amp load for several days, or with a 500amp load for several minutes, neither of these are particularly realistic test for the real world.

To even things out, they came up with the reserve capacity rating, this is how many minutes the battery will last with a 25amp load (which is a reasonable average for a normal car). Basically the RC is the same test as AH but with a fixed load, since the load is constant there is need to include it in the results and so the final value is expressed in time instead of load*time.

I agree with all the guys who said disconnect it completely and charge it overnight with a mains charger before replacing it.
It is not necessary to remove it physically, just depends on your locale. It probably was knocked around by your previous alternator so make sure your electolyte levels are up. You might also want to add some 'Inox', or similar, battery treatment to each cell. IMO it should be added to even new batteries, keeps them in top nick especially under heavy use. Good for reviving batteries too, I have used Inox for years but there are similar products around.
The testing with a multimeter is a great idea as it will reveal any previously hidden problems. Voltmeters are very limited in their utility, unless combined with an ammeter they reveal next to nothing. They really only show what's leaving the alternator not what the circuits do with it.
Also 'Amp hours' on a battery is a just selling point, heydonms hit it when he said 'reserve capacity' is a truer indication of a batts. value to the user.
Cheers,
Paulmac

Its a Optima Battery. There totally sealed. You can install the buggers upside down if you want.

So you cant add Inox or similar additives to it.
The battery will brobberly come back good with a long overnight charge.
Im just wondering if his new Altinator is faulty and discharging the battery back after the engines switched off.

Ah so, garsiph
I learn every day, the only Optimas I had used were golf balls, they didn't respond well to Inox either.
Your point about the diodes allowing current to 'drain back' is a good one, I had just raised that possibility on another thread here tonight and forgot to add it for him as well, brain fade..
Cheers
Paul

Yeah later on tonight i'll full disconnect it and leave it on charge, HOPEfully fingers crossed it will do the job, if not
What do you guys recommened for a battery? Keeping in mind that I have a pretty powerful sound system and will play it every now and then without the engine on?,
Also could you mention price range value for money etc etc..as xmas is coming up n thats going to be a hole in the pocket
thanks
- Ash