Replaced battery twice within a week

[Azeroth]

Hi, I'm away going to school away from home, so I no longer drive my audi everyday. My parents take it out once every week or every other week to keep it running. I went home a couple weeks ago for thanksgiving break, car drove fine. Dad got in the car last weekend and it wouldn't start, there wasn't even a clicking noise from the ignition, the battery was straight dead. So they replaced it that day. Just got a call this morning again from my Dad and the battery was dead again... No lights were left on, stereo was not on. Any ideas?

[DRAKLORE]

Alternator, or large draw

[Charles.waite]

Yea either the alternator is toast, or theres a large draw/short somewhere in the system.

[alhoward101]

Don't rule out that you could have gotten a shit battery, not very likely but it could have happen. Most places like pep boys or Firestone will do a charging system evaluation for $20 or so

[beantown]

Alternator, or large draw

x2 Alternator

[mr shickadance]

i feel like i am insulting you when i ask this, but any chance that the dome lights could be switched to on (again, im not tyring to insult you by asking i just know i have done that before and left my light on all night, i can imagine it would be enough to drain a battery in a week

[drumnjuny]

im paranoid my alternator is going too. car has trouble starting, and leaving the trunk open for an hour (trunk light was the only source of power draw) or two made it die out. when i jumped it the car started instantly for the next copule starts, but now back to the 2-seconds of turning before it starts [:(] there's no calcium deposits on my battery terminal either! sigh...

[Azeroth]

i feel like i am insulting you when i ask this, but any chance that the dome lights could be switched to on (again, im not tyring to insult you by asking i just know i have done that before and left my light on all night, i can imagine it would be enough to drain a battery in a week

I actually wish it was this so I could simply fix the issue, but yes I'm sure nothing left on in the car. Sounds like it could be the alternator, car in for service on tuesday so I guess I'll find out then. Thanks.

[doublezero30]

normally i would say alternator but the fact that the car sits the majority of the time kind of makes me feel like its not the alternator. How long do your parents drive it for (time wise)? a fully charged battery would only last about 45minutes or so without the alternator charging it. The fact that they only drive the car once every 1-2 weeks makes me think that it is more likely there is some sort of draw sucking the life out of your battery. plus, with the colder weather setting in it is more importent to drive the car as the cold weather can kill a battery. I wouldnt rule out the alternator...in fact testing it is simple and autozone does them for free i believe. but the little amount of driving makes me think its not the alternator.

[Operator]

Out of the two, ideas put forward, a large draw seems more likely to me. I actually need to troubleshoot a similar issue. Seems like in both cases the issue pops up after the car has sat for a few days. If it was happening everyday, then I might lean towards the alt.

[Charles.waite]

You could also get a trickle charger and leave it hooked up while its not being driven.

[doublezero30]

You could also get a trickle charger and leave it hooked up while its not being driven.

very good idea. [up]

[Operator]

You could also get a trickle charger and leave it hooked up while its not being driven.

That's what I'm doing when I'm at home, but the ideal thing would be to find the draw.

[DRAKLORE]

Most of the time alternators do not fail outright, they can get weaker and kill the battery slowly. This is what my truck does, to battle it I use a trickle charger/maintainer to keep it on the upside when it is parked.

[Brillo]

Sorry, have to disagree with the comment that cold weather kills batteries. I believe it's actually the hot summer months that are tough on batteries. The poor health of a battery will manifest in the winter for two reasons, the natural output amperage is less in the cold and the current draw to crank the engine over is higher due to the higher viscosity of the oil in the cold. As an additional point, the volatility of some gases will change in the cold weather making them a little tougher to ignite. Barring the other issues mentioned in the posts above, I agree that a quality trickle charger will maintain the health of the battery during periods of inactivity.

[makav3li]

im paranoid my alternator is going too. car has trouble starting, and leaving the trunk open for an hour (trunk light was the only source of power draw) or two made it die out. when i jumped it the car started instantly for the next copule starts, but now back to the 2-seconds of turning before it starts [:(] there's no calcium deposits on my battery terminal either! sigh...

A bad alternator means that the battery is not getting charged when the car is on. So the battery would die while driving, a fully charged battery will take about an hour to atleast see obvious signs of dying so if you can run the car for a long period of time just fine, your alternator is fine. Now if the battery is dying over night, chances are its a weak battery that just slowly loses its charge while sitting there. Otherwise a short that draws power from the battery when the car is off is a good possibility. When you turn the car off, open up the hood and listen to hear if you can hear any motor running or a fan blowing. I know my abs controller had a short on one of my older cars and would kill the battery after a few hours of sitting there.

[DRAKLORE]

Here's a little fact, your wrong^^^ yes an alternator that straight up fails will cause the whole- weakening power level running off the battery whole everything dims and then eventually the car stops.

But I'm saying his alternator may not be putting out the proper voltage/amperage. Very common.
A draw is easy to test, pop the hood leave the car for twenty minutes, when you come back do not open any doors or anything, then hook up a volt meter to the battery and watch for a small drop in voltage over time