Battery fails to quick
 

Hey guys, I haven't been here for a while but I have a quick question. I had my battery replaced about 6-8 months ago and everything has been fine. Lately my battery dies after less than 30 mins of playing the radio (and only the radio). I know the cold can make it die faster but is it really going to kill it that fast? I usually could keep it on for over an hour easily.

I'm sure this is a simply question but thanks in advance for any help.

p.s. there is no signifigant amout of rust and all connections are tight. Other than checking that I really don't know much about much.

Take your car to AutoZone and have them check your battery for free.

If you bought 6-8 months ago if should have a warranty.

It "fails to quick"? I was unaware that quick was a verb. :wall:

Your alternator may not charge sufficiently.

My alternator only charges at 11 volts while running, this causes my battery to die much faster without the car running. Other than that I dont have any problems with it and I've had my current battery for well over a year (the old battery totally died or 'sulphated', i jumped the car, the alternator suffered the consequences).

Go to advance/autozone/maybe pepboys they should be able to test your whole charging system and let you know whats going on.

P.S before you know for sure try not to leave accessories on while your car isnt running, the more your battery dies the worse off it gets

What's the drain on the battery when the car is off? Some electronic devices may consume a few mA, but look for an abnormally high drain when the engine is not running.

Also, is the alternator charing properly? Do a battery test and alternator test, should be free at some shops.

Depends on the radio...

If it's the same radio/volume which used to be running for 1 hr than dropping from 25C to 0C will take about 30% off the capacity. Taking 8 months 'age' into account which further reduces capacity I really don't see a problem.

If you change your favorite recordings to the ones with a lot of bass then on a good sound system you won't last long either :).

Second'd. What you are looking for is called parasitic draw. Which one of your (I presume) aftermarket components is sucking juice from the battery when it is "off?"

Until you find what's causing the problem, you should just try listening to the radio with your car idling. ;)


@Klemenz: Should our cars be putting out 14v from the alternator? I checked mine after my car randomly wouldn't start one moderately cold (~45F) morning and, with everything off save a muted CD player, it was only reading at 11.5v, if I recall.

For you guys with UDP be sure to check your altenator output @ around 1000-1500 rpm and you should be seeing 14v plus charging if not you've got a serious problem with your altenator! Checking for that parasitic draw is easy....disconnect the negative and attached a VOM between the battery and the now removed negative lead.....remove the clock & ecu fuse and measure the draw......and anything over .5 volt draw you need to locate the circuit by pulling fuses...GL!!!!

Sorry, parasitic draw is irrelevant here. If it was the case he'd complain his battery gets discharged on its own overnight (while still have normal capacity). In his case everything is OK until he turns on the radio.

BTW, your alt is dead if that voltage you measured on the engine running at 1k rpm. If you simply measured it after sitting overnight even before starting the engine it could be anything, including 'parasitic draw'.

*thinks* Hmmm, no that was probably with it idling at 625 rpm. I looked it up in the FSM and, oops!, I might have just found a troubling truth about my car.



Well, if his battery is failing too quickly, I don't see why checking for every common electrical problem is "irrelevant." Let's say he hooked up something that is drawing from the battery when it's off. Okay, the battery slowly loses juice as if the alternator weren't working properly. The alternator charges it back up, but the draw continues... Then, when he's sitting in his car listening to some bangin' ch00ns and his battery dies, can we definitively say that it was only his stereo that drained the battery, and that it was drained in that one half-hour sitting? Ehhhh... I don't see how that's realistic.

How does a parasitic draw not reduce charge and capacity? The battery is experiencing more draining and filling cycles (or whatever the terminology is for car batteries) from the draw, so wouldn't that prematurely lower capacity? Why would a parasitic draw always have to be so strong as to completely discharge a battery overnight, every night?

Also, something obvious and dumb I missed, did you buy a cheap, crappy, low CCA battery, OP? With poor battery hygiene and a crappy or defective (or both!) battery, maybe 8 months is all it takes to discharge the poor thing?

Is this battery a serviceable wet cell type with removable vent caps? Remove the caps and test each cell if you don't have a charging system analyzer.....Each cell should measure 2 volts each....you may have a bad cell or several!

Thanks for all the input guys. I haven't been able to do much besides carry cables around since I've been a little busy.

So the next morning my car didn't start again after only sitting over night. I didn't see anything that I left on. I haven't had time to get the alternator or battery tested at autozone but I will the next chance I get.

With that said, the car has started normally except those 3 times. That includes sitting outside over night again. My guess is the alternator. Sounds like the beginning of the end.

Sounds like sh!tty battery to me. Simple voltmeter check when engine is running at 1k rpm could reveal if your alt is indeed bad.

From my experience, bad starter (the one which cranks slowly on the fresh battery) kills brand new battery in 6 months. Bad alternator (the one overcharging the battery at 14.8 volts and up) kills it in 1 year. The latter never happened to Maximas, it happened on other cars.

Statistically POS battery from local Crappy Tire lasts 8 months in average, then it behaves like yours - loosing charge overnight, refuses to start, etc. Of course this all happens when cold weather sets which makes battery's life harder. I used to replace them once a year. I was foolish enough to buy their warranty story which turned out to be complete ripoff - they pro- rate your battery when you bring their dead child back: if it served you 1 year out of 4 they warrantied you have to pay 1/4 of its price to get a replacement. So, at the end of 3 year period (and 4 year warranty) you end up paying 2.5 of its initial price plus hassle to carry it around when it dies. This would be acceptable for the quality product but not the one which fails in more than 50% during warranty period. I'm referring here to their Eliminator series- complete POS IMO. Only 1 out of 4 survived past 4 year period, 3 others were replaced yearly. I finally got fed up and went with Optima Red Top from Wall Mart, haven't had a problem since. All Eliminators developed internal short in one of the cells which readily discharged that cell within few hours. One dead cell won't let you start the car and it cannot be charged separately from the others. So battery goes into this suicidal curve - dead cell can't take charge while others gets over- charged and damaged as a result.

BTW, listening to the radio up to the point your battery dies is a bad idea for conventional batteries. They belong to so called 'starter' type which is able to provide high current during start but doesn't like to be fully discharged. To do that you need Deep Cycle type of batteries, those will let you do this and not die in the process. Optima makes exactly this type - take a look, they use better technology and IMO worth every penny.

In OP original post he stated his discharge time fell in half. Let's say his car developed 'parasitic draw' equivalent to the radio. Working together they'd discharge the battery in half the time - 30 min. Trouble is that 'pd' would need only 1 hr to discharge it on its own while OP didn't report such short times, that's why I considered your idea as 'irrelevant'. Later on he changed the story stating the car had troubles starting after simply sitting overnight so now your 'pd' idea becomes relevant and valid. Probably you read between the lines :). I still think that the draw happens inside one of the battery's cells and not in the rest of the car. He could easily check it though using multimeter in the 'ampermeter' mode.

You are also mixing up few terms - capacity is the ability of the battery to take charge. The charge is the actual amount of electric charge held in the battery. It equals to capacity only on fully charged battery (whatever its capacity happens to be). Parasitic draw can reduce charge but not the capacity. Moreover when engine starts alt takes over and brings the voltage in the system to 14.4V. At this voltage battery becomes one of the loads but not the source. Whatever draw he has in the car won't be seen by the battery as long as the engine is running.

CCA rating is mostly marketing gimmick - a car needs around 100A to start, cold or not. When they state 900CCA they basically specify how much current a battery can provide if you short it. While it does provide indirect peek into battery's health it is poor criteria to compare different brands or types of battery. Who cares if it can give you that current but it lasts only 1 year and then shorts one of the cells internally due to poor design and corrosion? Under 'corrosion' I mean here the process which eventually destroys electrodes inside the battery, it has nothing to do with rust or oxidizing of the battery posts. Basically, you can't stop or clean it, it is part of any battery's life which eventually kills it. The only question is - how soon?