mrkatt

Hi guys,

My 2000 TL that I left parked in my garage for 9 days, had a completely dead battery when I went to start it. I mean dead, no horn or anything! I put the jumper cables on, the cars electrical came back on, and the car started right up. I didn't find anything on, all doors shut, nothing on the car aftermarket, and the battery is brand new ( 2 months old). What do you guys think?

Thanks,
Jason

vincethe1

was it locked? if so then the security system also sucks up a little energy...although i wudn't think nearly enough to drain your battery...but it's the only thing i cud think of

the radio & clock also work partially to keep memory, as well as the engine's and transmission's ecu...when you combine all that + how long it sat it shud have some discharge but it shudn't be enough for everything to be dead.

my 2006 TL sat in the garage for about 3 weeks (when the car/battery was 2 years old) with a total radio work time of about 5 hours, and at the end of those 3 weeks it nearly started, it still had power for everything else, but not the starter...so you eather have a defective/really crappy battery, or you have something that's constantly draining power that you are unaware of.

TLS101

What brand of battery is it?

It should last longer than 9 days. I go on vacation and leave my car parked at the airport for 17-24 days and never have any worries....You've either got something draining your battery or a crap battery to begin with...

acutee

defective battery or bad aftermarket alarm system if you had one.

01tl4tl

even new batteries have a bad cell sometimes- or the cables are bad-dirty, and/or a loose ground somewhere is causing a problem

First thing is: a trip to the parts store for free test of the battery

Note to all; Its REALLY bad for batteries and especially the alternator-- if you jumpstart a dead battery-
You should ONLY charge it with a seperate charger!!!
The alt was only designed to REPLACE energy drawn from the battery in use driving- not to recharge from a dead state- thats a lot of amps~
The battery is designed to lose a little and get replaced (exception for deep cycle style)
its not designed to go dead then hot shot it with juice

vincethe1

^^i'm sure that at least 90% of people have jumped their car from dead and let it recharge...you are wrong, the alternator IS made for that because it is a very common thing to forget your lights and drain your battery...

the alternator will have a higher load on it and will heat up more while charging the battery, and it will be at full charge...but it is meant to do that, although it pust more overall wear on your alternator it's the same thing as flooring your car once in a while, it's not really bad for it just puts more wear on it.

if your alternator fails while charging a dead battery then it was about to fail anyways, you just pushed it over the edge.

it is however very bad for the battery, comming from a complete dead state the battery will never be the same, and is likely to fail years sooner than it would have otherwise.

bibledriver

I agree with both of you. Yes, alternator shouldn't be given the task, but CRAP, my wife left her dang lights on and She needs to get to work. JUMP START, or even if it finally BARELY starts, that's what I'm a doing! I don't have time to R&R a batt, or slow charge it. Where it is not ideal and hard on the alternator, the alternator will be fine and battery is harmed more than the alternator.

The disclamer on the battery is CYA. They can't prove that the new uncharged battery didn't cause the alternator failure, so put a disclamer negating their liability.

acutee

Good advice. , but of course in an emergency situation you need to do whatever you need to do, but rectify the problem as adviced; and surely you want to avoid overloading the alternator.

01tl4tl

In an emergency is different that normal situations
And even those who disagree still understand that HEAT is a killer to boththe alt and battery-
the alt was Not designed to recharge from dead- the full throttle useage statement makes no sense,
and I have been working on things for decades-
20-somethings have no standing in life on matter of car repair and longevity of parts IMO

bibledriver

No, it is designed to power your car and refresh your batt., not charge it.

I don't know about that, the edge could be far away and you could have forcibly THREW it over. Definitely not best practice you must admit.

vincethe1

ok..another thread getting out of hand here, what do you mean it's not meant to charge the battery from a dead state?? who in the hell gives you this information?? do you think we have 120amp alternators that make close to 1000 watts just to keep the battery refreshed??

OF COURSE that's it's main job, but it is also made to completely recarge the battery and not break.....because in a car's lifetime that will probably happen quite a few times.

OF COURSE the alternator would rather keep the battery than have to recharge it, the most common alternator failure is wear of the brushes...again, the more the load on the alternator the faster your brushes will wear out, granted, but it don't mean it is instantly bad for your alternator.

what about all the ppl that put subwoofers in their car, that sure shortens the life of an alternator and battery but it doesn't blow it out as many of you may think.

bibledriver

So, it is best practice?

read the posts. NOT BEST PRACTICE. That's it. No arguing to it. Calm down.

I would hardly call responding to your absolute statements to be "out of hand." Keep it calm and it will be fine.

Alternators don't have preference, they have design, and 01tl is right, they are not designed to charge batteries from dead. This IS why when you get a new alternator, they tell you to make sure that your battery is charged (being that it may have be drained from your bad alt.) and won't replace it when it dies if you state you didn't charge your batt first. Your car has an alternator, not a generator.

vincethe1

to the original poster: I think i might know what's going on...you might have a charging problem...when you put the car in the ON position does your battery light come on at all? It should, until you start the car then it should go off...

eather that or you could have forgotten the interior lights on...that'll drain it in 9 days.

bibledriver

original poster, get a new batt on warranty, check your aternator, that may not be charging like it should and do it for free where you bought the battery. or autozone or equivalent where you are located.

vincethe1

lol...where in my statement did i say that it is better for the alternator and therefore it is best practice?

no it is not best practice, neaither for the alternator or the battery...but it won't hurt the alternator, i've done this many times to many of my cars when the batterys die and have yet to replace an alternator.

when you get a new alternator they say that to protect themselves out of their liability...if the battery is defective or is done to a point that it cannot be recharged and hold a charge by itself for more than a few starts, then the alternator would be charging a dead batter that's literally shortening the alternator and causing it to overheat and burning it out...so when they sell you a new alternator they wanna make sure you have a good battery so it don't burn it like the previous one.

another thing...do you even know the difference between alternator and generator?

i think not, so i'ma explain it...generators is what the older cars used to have...alternators is what the newer cars have.

the difference is that the generators needed to spin up a lot faster to make the required electricity, the alternators make a good charge at engine's idle.

the name alternator comes from alternating current (AC) which is what it makes...now the battery cannot work with AC, it is DC, so there's diodes to convert AC to DC.

so as it turns out, the alternator IS a generator, but just a better one

bibledriver

dang, wonder why when your houses power goes down, you use a generator. Or when you get on an aircraft the electrical is powered by a generator? They should use alternators, then!
wow.

:wink:

vincethe1

hahaha, wow....you're reallly hard headed.

it's a name, some ppl call it generator some alternator (in a car)

an actual generator that's powerd by a gasoline engine and used to back up power is called generator because it generates electricity to back up power, therefore a generator.

The generators that back up power to a house, tent, w/e make AC electricity, because taht's what your house uses...so yes, i guess they do use "Alternators" afterall