Went to hop in my TJ2 tonight for a drive and nothing. Looks like a flat battery.

Heres the tricky thing though, this happened a few months ago, suspected the battery as it was a few years old. Replaced the battery and everything has been sweet since. Now it has happened again i'm starting to think something else must be wrong. The car seems to run fine if jump started, so the alternator seems to be doing its job. Plus no battery warning light has lit up which usually happens if the alternator/charging is faulty?

So my other thought is there must be a voltage drain somewhere. I haven't changed my vehicles electronic setup in the last year at least, so i'm not sure why this is happening now. Is there an easy way to find out what could be happening? Any other ideas guys?

I'll try my car again soon to see if it's definitely the battery and not some intermittent problem, but my stereo couldn't power up and not even my central locking remote is working (you can hear a faint click when i press the button, but nothing happens).

Also I forgot to mention, I drove the car fine only 3 hours ago, didn't show any signs of failing to start or anything. Didn't leave any lights on etc. It's like it has gone from fine to dead in only a couple of hours.

Measure your battery voltage with a multimeter. With the engine off it should be above 12V.
Disconnect one of the battery terminals and measure the current drain. Do this with the doors closed so the interior lights are off. Shouldn't be more then ~50mA

With the car running above idle again measure the battery voltage. If the alternator is doing it's job should be 13.8-14.4V

If the alternators charging then it sounds like you have an electrical short somewhere. Also possible your new battery has a collapsed cell.

I just watched the interior light fade away into nothing, so the battery is now completely dead. I'll do some multimeter tests tomorrow when it's daylight, hopefully can get this fixed before work tomorrow night :). Is there any easy way to tell if a battery has a collapsed cell?

I'm guessing if the alternator is charging fine i'm stuffed because I have no idea what could be causing the short, and if there is one I can't understand how the battery can last this long, but then after 3 hours of starting the car on its own power is completely dead. Unless is an intermittent charging issue, but even if it's not charging properly don't you get a warning light on the dash?

This is why I'm completely confused because I can't think of what would cause these symptons.

Is your battery a maintenance free one or no? If not check each cell for fluid if you haven't done so already. My guess is on something draining the battery though, i would imagine it'd have to be a substantial component though if its draining the battery in 3 hours!

Hmm, not sure how you would do that at home. Need a battery tester to do it properly. Basically put a known load on the battery and measure the voltage drop.
For now I would disconnect the battery and put a charger on it ASAP. Leaving a lead acid battery fully discharged for any length of time is not good. If the battery's not at fault you don't want to kill it.
That will also give you an idea if it will hold a charge.

Is your battery a maintenance free one or no? If not check each cell for fluid if you haven't done so already. My guess is on something draining the battery though, i would imagine it'd have to be a substantial component though if its draining the battery in 3 hours!

Nah its not maintenance free, its a century heavy duty (520cca) battery, only a couple of months old. Will check fluids in the morning.

The thing I don't understand is, the problem went away with the new battery, and i've driven the car at least once a day since, so if it was a charging issue I would have thought i'd notice it within a week or so. And for it to last all this time, only to drain in 3 hours boggles me :tired:.

The only thing I can think of, is the alternator is BARELY working, enough to keep the warning light off, but not enough to keep the battery charging more than the charge needed to start the car. Don't even know if that's possible to be honest!

Hmm, not sure how you would do that at home. Need a battery tester to do it properly. Basically put a known load on the battery and measure the voltage drop.
For now I would disconnect the battery and put a charger on it ASAP. Leaving a lead acid battery fully discharged for any length of time is not good. If the battery's not at fault you don't want to kill it.
That will also give you an idea if it will hold a charge.

Don't have a battery charger and doubt anyone would sell one at this time of night lol. Will try and jump start in the morning and get to the local auto elec I guess. Would be good to know whats the cause before i get charged for the labor of trying to find it :P.

I went through a couple of batteries like this in the wagon, I found the best battery I ever had was from a place in Smith St North Fitzroy Ariel Batteries I think the name is. Their batteries seem to last forever.

Just tested the voltage at the battery, apparently it's sitting on 12.65/12.66 which I hear is perfectly normal.
The mulitmeter here says it can measure current up to 20A, but when I tried it stayed on 0. So either there is no current (quite possible if the battery is completely dead) or i'm not using it right lol. The indicator on the battery also has a very solid "Green" which means good.

This may sound rather simple but remove terminals and clean battery terminal and leads with a wire brush or sand paper. It sounds like your battery has life but just getting any to the car.

Sounds like you need a drain down test on the battery to check its working capacity.

This may sound rather simple but remove terminals and clean battery terminal and leads with a wire brush or sand paper. It sounds like your battery has life but just getting any to the car.

Dad's awake now so i'm going to get him to check the voltage as i try to crank it, if it drops i know the battery is dead, if it doesn't drop then you could be right.

Anyone know of a good auto elec who services the berwickish area? I've been to the one in enterprise drive and he was good, but not sure if he does house calls lol. If I get it jump started I should hopefully be able to limp my car there anyway.

OK now i'm even more puzzled. Terminals are fine, no sign of corrosion. I tried turning on the headlights, cranking the car etc., there was a slight drop in voltage across the battery terminals to 12.55, but I would expect to see a much higher drop if the battery was dead?

Will call an auto elec i think, even my dad who is an electrician said it doesn't make any sense lol.

OK now i'm even more puzzled. Terminals are fine, no sign of corrosion.

Yeah ive seen battery terminals not making good contact before and they looked perfect. Best thing to do is pull them off and clean them up anyway. You cant see if its making good contact.

Yeah ive seen battery terminals not making good contact before and they looked perfect. Best thing to do is pull them off and clean them up anyway. You cant see if its making good contact.

Mate....I could KISS you right now!
It actually worked. Scared the life out of me as the alarm must have been setoff when I had to use the key to open the doors this morning, took off the terminal, was fairly dirty/rusty on the inside, used sandpaper to get most of it off. Put the terminal back on to get a thumping horn in my face LOL. Car started up straight away.

Now the big question, should I take it to an auto elec still so they can give the terminals a checking over/clean/future proofing etc.?

Just did a voltage check on my old battery, yup it's registering good. Teach me to replace things without checking first. At least I have a spare battery now if I need it :).

there is no need to go to the auto elec, he will just rip you off. if your terminals get too bad, you can buy new terminals pretty much anywhere. pretty cheap as well.

should I take it to an auto elec still so they can give the terminals a checking over/clean/future proofing etc.?

Sometime people always miss the simple things. I dont but i guess cause im a bit of a simple guy. I dont know about Future Proofing the terminals. You can get a few sprays(Yellow/Bue) that you might of seen that is ment to prevent crap on your terminals. Ive never been a big fan of them. I would just give them a real good clean yourself and make sure you do both battery and car terminals. If you walk into a business they will always want to see you smething. They dont always work that good. After all they need to pay the rent somehow.:)

Vaseline.
You can even put it on the battery terminals as well!!


Gerry

I went through a couple of batteries like this in the wagon, I found the best battery I ever had was from a place in Smith St North Fitzroy Ariel Batteries I think the name is. Their batteries seem to last forever.
They're actually in Clifton Hill, but yeah I agree, awesome bloke there, he supplies and fits all the batteries for the Yarra council cars, so I get them at the cheaper council rate. I admit I've had a problem once, but how he goes with his warranty claims are brilliant, tests the battery in car, agrees, puts a new battery in and your on your way within 10 minutes. Good old quality service!


Mate....I could KISS you right now!
It actually worked. Scared the life out of me as the alarm must have been setoff when I had to use the key to open the doors this morning, took off the terminal, was fairly dirty/rusty on the inside, used sandpaper to get most of it off. Put the terminal back on to get a thumping horn in my face LOL. Car started up straight away.

Now the big question, should I take it to an auto elec still so they can give the terminals a checking over/clean/future proofing etc.?
That should've crossed my mind actually, I had that exact problem with my car, I had to have the positive terminal half on half off to get a connection, if it was all the way down sometimes I'd turn the key and the whole car would just die, literally everything. Anywho glad you worked it out.

I'd buy a simple battery clamp/post tool, there is one type is cross-shaped cast alloy with two scrapers and a reamer. Another type is like wire brushes, a round one to do inside the clamp and a "donut" one (brushes facing inwards around a bigger circle) to clean up the battery posts.

I like the old-fashioned "boiling water and washing machine powder" clean-up with old toothbrush etc (works best if you also steal a kitchen vessel of some type - keeps the wife or mum happy abusing you!!). If you can actually dunk the terminals in this hot soapy brew is good way to go. Then scrub with the old toothbrush to remove stubborn bits of corrosion salts. Pour the brew over the battery posts while giving them a scrub - BEWARE of flicking residue over yourself or the car, it may be acidic and ruin whatever designder t-shirt you wear to service the car.

Then give the clamps and battery posts a clean-up with the tool of choice (ordinary wire brush is OK to run around battery posts too) - you want to take as little metal away as possible, but have a noice shiny surface, not dull oxidised lead colour. Rinse the whole lot and battery tray with lots clean water - don't want old corrosion eating anything away down there! Allow to dry, or could blow-down with air-hose (again, careful not to blow bits of old corrosion into engine bay or sensitive orifices (like eyes dammit - get your minds out of the gutter).

Then reattach your clean/dry clamps to your clean/dry battery posts. When the clamps are metal/metal on battery posts but not tight, some like to wiggle the clamp from side to side to mash the metal into the metal, giving super-ultra-good-contact...... this may be useful or may be an old husband's tale.

I used to quite like cheap felt washers which went on posts under the clamps - one red and one green - and said to be impregnated with anti-corrosion stuff. Haven't used them for a while. You can also smear the clamps and posts with vaseline to coat them and help prevent future oxidation and corrosion. My latest idea for this protective coating is a pressure-pack of White Lithium grease I bought (and there's only so many things I can use it for) but that's probably wasteful - I just like the idea of grease in a spray-pack! It seems to work, but is possibly an expensive way to do a simple job that in no way requires white lithium grease.

I have learnt over the years to suspect this simple cause that Jason suggested - we had a TN which has passed dowb thru the family about 3-4 times and is still a paddock basher - dud contact at battery terminals was a problem with that car several times. Could look perfect, but NOOOOO.

Elwyn, I guess you are referring to one of these, very handy

http://www.harborfreight.com/cpi/photos/94400-94499/94450.gif

got a pee pee at one end and a veejay at the other

Spot-on Pete!! You are a legend - a picture is worth a thousand words. Your pic much clearer than my waffle.

there was a slight drop in voltage across the battery terminals to 12.55,

12.55 is not bad, below 12 you probably wont be able to atart.

Just go warm water and bi-carb soda. The bi-carb will neutralize any acid around the terminals and help prevent it getting worse in the future. If you go to any supercheap store you can buy a little single use sachet of battery terminal oil stuff that protects them pretty well.