car won't start, is it the alternator?

[loveless]

Yesterday it was raining a bit in the morning. I drove to work with the lights on (hid, probably drain power a lot faster). When I got to work I forgot to turn it off so of course, by the afternoon, I had no power at all.

I had a coworker jump my car but it was difficult. I think nothing of it because his battery is old and crusty, I asked the owner to rev his engine and I was able to start the car. I drove home to eat lunch and about 2 hours later I am not able to start the car again and the power is diminishing (hard to roll up/down window). Tried to jump the car again and it won't start. I hear repeated "clicks" (is that ignitor chip?) but seems like there isn't enouhg power to turn the starter.

1) I am guessing it's the alternator? 2) will draining power completely (like leaving your lights on) has an impact on alternator?

[Ritz S14]

Since you drained your battery down completely, it will take a while to get a full charge. If the battery is old, just replace it anyways. If your battery is in good condition, have it set at a slow trickling charge for about 6 hours or so, that way it gets it's "full" charge back.

While the car is running grab a volt meter, measure voltage across the battery and make sure you're at about 13.8-14.4 volts or so. If you're within that range your alternator is working accordingly. If you rev the motor it should slightly increase a few tenths of a volt. Or you can always bring it to chucks/kragen where they offer free alternator/battery checking.

If your alternator was bad, and you have a low battery your car would not run. The alternator is what keeps the car running while the car is running. The battery only supplies the car cranking power to start the car, but does not supply the car with running power..the alternator does.

Most likely, your battery is in poor condition. Lastly, IIRC HID only takes up more power during "start up", while it's on, it takes less current than your regular halogen bulbs.

[loveless]

the battery is less than 1 year old, it's the wesco small battery

if it is indeed the battery like you guys said then how come it won't crank when I have the car jumped?

and what's a "slow trickling charge"?

[Ritz S14]

I don't know about the small batteries, but I don't think they will work long term.. Not that I have any experience with them.

Alternator has nothing to do with your starting system once your car is off. Alternator keeps the battery charged while the car is running. If your current battery is too small and is currently low, sometimes when jump starting your car, your car will not be able to crank. Because you have a small battery, the jumper car is trying to feed your battery power, as well as your starter. So it's doing two things at once. And it sometimes is not enough.

Slow trickling charge, is when the battery charger charges the battery at a really slow rate. Usually when you charge at a slower rate you get more of a complete charge than a quick rate. Once the battery is full, the charger will continue to charge the battery at an even slower rate to keep it close to 100% charged.

Quick charge = You eating a snack
Slow charge = You eating a meal

A snack will fill you up now, but you'll be hungry later. Get what I'm saying?

[loveless]

that makes sense, but all I have is a jump cable, I don't have anything to do trickling charge

[Yoshi]

well what he's saying is you have to do 1 of 3 choices:
1) get a real charger, something that can charge at a sustained 10amps at least, this will charge your battery is a couple hrs, depending on what it's CCA rating is, for reference, my Odyssey 925 drycell should be charged 2.5hrs @10A for a full charge of a completely discharged (dead) battery.
2) get a trickle charger and hope that whatever drain u have is LESS than the rate the trickle charges goes at (typically this is 2-3A), trickle chargers are SLOW, like overnight slow, and if u don't get the right kind, u run the risk of overchargine
3) LEAST RECOMMENDED - if your electrical system is working right, you should just be able to drive around for a LONG time and have your alternator charge your battery, this is really bad for your electrical system tho.

Jumping the car is basically adding another battery in a parallel circuit, it's not charging your battery, just helping it start the car. Killing your battery by leaving your lights on should have no affect on the alternator.

I'd recommend getting a real battery charger, they're not that expensive... in fact here's a cheap one :)
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=3418

Definitely tho, go to schucks/kragen/checker/autozone/pep boys/etc and have them load test your battery. You should be putting out MINIMUM 350 CCAs

[loveless]

surely enough, it's the battery, however, the battery is rated at 450cca and after 45 min of quick charger at autozone only got about 310cca, shodul I be concerned?

[Irukandji]

ur alternator takes a VERY long time to charge your battery.. trust me.. samething happened to my father's bmw. you're better off going to a local garage/auto shop and asking for a battery charge... we got out battery charged for free.. but I hear some places charge about $10.

if you want to charge it using ur alternator.. its gonna take a LONG time.. and be sure to turn off EVERYTHING .. including lights, stereo, ac, fans, everything... you want as much power going to ur battery as possible.. but id say thats a waste of gas.. just pay $10 and get your battery fully charged..

just my 2 cents

[Irukandji]

about the cca.. keep charging it.. my dads battery took 6-7 hours to charge... because the battery was completely dry.. jus charge it until u pass or meet the CCA, then you should be able to start ur engine and drive around just fine.

[ace240sx]

The alternator will not work properly with a dead battery, it needs 12V across its field windings so it can generate voltage.

[Irukandji]

The alternator will not work properly with a dead battery, it needs 12V across its field windings so it can generate voltage.


ooo... hmm.. i learned somethign today.. :rolleyes:

[Ritz S14]

Man. That's not true. An alternator will work regardless if you have a battery or not. You can jump start a car, and remove the battery and the car will continue to run. But you're stupid to do this, because with out a battery, the regulator sees no voltage, and can spike up to 18volts and fry your ECU. So if you're smart, do not attempt to do this.

Voltage supplied from the alternator is to mainly keep the car running(ECU, injectors, headlights, HVAC, and etc), and secondly, charge the battery. The battery's main function is to have enough Cold Cranking Amps(CCAs), to energize the starter to start the car. Now an alternator generates alternating(field windings) current(AC), which through the rectifier, is tranformed into direct current(DC).

An alternator will overwork itself on a low/dead battery. You can not revive a completely dead battery(yes, I'm sure someone has before, but it's not likely). When you jump start a car successfully with a "dead" battery, you can overwork the alternator, which can cause teh battery to gas up and explode. Since the battery isn't able to Absorb charge, the cells get really hot, tend to boil..and *kaboom*.

A regulator is inside the alternator(older cars are external, and some GM cars are in the ECU). A regulator's role is to regulate how much voltage is supplied from the alternator, so that you don't overcharge(or not charge) the circuit.

[loveless]

thanks for everyone's help, especially smogtech's useful infos