How do I know if my car battery is dead?

vivekian wrote in news:0211b9b9-cdba-4a3e-867d- snipped-for-privacy@vs2g2000pbc.googlegroups.com:

What exactly happened when you tried to start the engine?

1) You heard and felt a "chugga chugga" noise from under the hood, but the engine never coughed or sputtered or showed any sign of wanting to fire up? 2) You heard and felt a "chugga chugga" noise from under the hood, and the engine coughed and sputtered but would not fire up? 3) You heard and felt a "chugga chugga" noise from under the hjood, but it was much slower than you're used to? 4) You heard nothing but clicks from under the hood?

Its no 1., I would think. There is definitely no engine coughing there. Also I can open and lock the car from the car keys itself instead of manually unlocking it. It almost looks like there is some charge there.

But it could be no. 4 as well. Is the 'chugga chugga' sound a loud one? What I hear is definitely not a loud sound.

vivekian wrote in news: snipped-for-privacy@pg2g2000pbb.googlegroups.com:

Impossible for it to be #1 and #4 at the same time.

It's the normal sound of the engine cranking. It's the normal sound and vibration you get before the engine starts.

Let me put this another way: When you turn the key to "III" (start), do the noises under the hood sound the way they normally do? Or are they somehow different?

If they are different, please describe how: louder? softer? faster? slower? higher-pitched? lower-pitched?

snipped-for-privacy@pg2g2000pbb.googlegroups.com:

Its definitely no. 4 then. Lower pitched and a few clicks.

that's a low battery.

Just go ahead and buy a new one. It's not expensive, especially for the peace of mind you get.

vivekian wrote in news: snipped-for-privacy@k14g2000vbe.googlegroups.com:

Next test: Turn on the ceiling light, then try and start the car. Does the light go out when you turn the key?

If so, then the battery needs to be replaced.

Did you ever have the red "Battery" light on the dsshboard illuminate while you were driving?

Go to an autoparts store. Where I live "autozone" will test the battery for free.

By mistake, I left the headlights on overnight for my Honda Civic

2008. 24 hours later when I tried to start it, the car would not start and nothing would come on including the internal lights and the dashboard LEDs.

Later AAA guy came and jump started the car and I drove it around for around 30 minutes. Today when I tried to start the car, it did not start up. Though the internal lights and dashboard LEDs are lit up.

How do I know if the battery has to be replaced? Or that it just needs another jump start and a good warm-up?

The battery is probably bad -- my experience with Honda batteries on a 2006 Accord and 2009 CRV is that they last about 3 years.

Hi,

Is it not the case that leaving the headlights on for 24 hours will completly discharge the battery.

Getting a jump start will usually start the car but running it for 30 minutes wil not recharge it. With battery drain fron ancilliary equipment I would expect it to be nearly flat the next day. If the battery was OK before the discharge then it will probably be OK after it is recharged.

Put the battery on a charger for 24 hours then put it back in the car and start it.

If starts OK each day from then on you probably don't need a new battery.

If believe the battery needs to be fully charged before Autozone can test it as they perform a "Load Test" which should determine if the battery will work OK when you have headlights, AC, radio, etc, running.

Al Moodie.

Al Moodie wrote in news: snipped-for-privacy@4ax.com:

A weak battery will shorten the life of the alternator through heat. Alternators are meant as top-up devices only.

The best way to test the battery is simply this: Key OUT,

1) turn the headlights ON, adn wait 5 minutes 2) turn the headlights OFF again, then wait 5 more minutes 3) check across the terminals with a multimeter set to DCV.

If the voltage is less than 12.65V and the alternator charges when the engine is running, the battery canot hold a charge and and must be replaced.

eh??? so the window defrost, the wipers, the seat warmers, the lights - all these are supposed to run on what exactly??? and their load is /what/ compared with battery charging load???

absolutely untrue. open circuit voltage has absolutely no bearing on battery health whatsoever. the only proper way to test the battery is to measure voltage with high current draw.

most shops and even service stations have proper testers. and they'll test your battery for free in the hopes they can sell you a new one. simply take advantage of this and stop this backyard witchcraft made-up-as-you-go-along b.s.

Al Moodie wrote in news: snipped-for-privacy@4ax.com:

This is the best advice I have heard yet...Years ago, I took a basic automotive class (mainly to get use of a shop) and the instructor gave us this example; "A car with a totally dead battery, jump-started in Chicago IL, would have a fully recharged battery by the time it reached Memphis TN"...This was assuming a normally functioning alternator, normal vehicle operation, etc......DaveD