How long should car run to recharge battery? [Archive] - Chevelle Tech

: How long should car run to recharge battery?


soccerguy045
Aug 27th, 04, 11:22 PM
I had something in my car called AC Anywhere plugged into my cigarette lighter. Some might not know what it is, but you plug it into the cig. lighter and it attaches to a big transformer so you can plug regular plugs in there (computer plug, cell phone charger plug, etc). I had left the switch 'on' but nothing was plugged in, but I guess it still sucked my battery dry sitting in the parking lot all week. I went to start and classic signs of dead battery. Had a friend jump me but it took a while for my starter to turn enough to start my car (his little PT cruiser trying to jump my Chevelle didn't work too well). I only let the car run for about 3-4 minutes before I had to go back to my dorm. This morning I came back and it cranked for a second and the solenoid then just clicked a lot, and then dead again. About how long does it normally take my engine running with alternator putting out voltage to charge the battery back up enough so I could start it again next time? Have to go back home tomorrow for a wedding and plan to put to hook the battery up to a charger then. By the way, that AC anywhere thing is unplugged now.

Thanks in advance

John_Muha
Aug 28th, 04, 12:02 AM
An alternator is not a charger.
An alternator will not recharge a dead/weak battery.
If the battery is run down it needs a charge from a battery charger.

soccerguy045
Aug 28th, 04, 12:20 AM
So if I run the car for 10-15 minutes to get gas, turn it off and fill up, I won't have enough charge to start again?

Do alternators only charge already full batteries? I know it doesn't charge 'per se', or does it? It seems to me if you have an alternator putting forth a charge that's why you don't need to replace a battery all the time when you start a car.

I'm not disputing what your'e saying since you've helped me out so much before, I'm just curious and trying to learn a little smile.gif .

I'm mainly just concerned about getting back home to charge it and don't have enough gas to get back. No outlets to charge my battery in a college parking lot. Thanks for helping!

67SS138
Aug 28th, 04, 12:55 AM
Taylor,
take the battery out and charge it where you can hook up a battery charger. A Alternator charges the battery when it is running to replenish not to charge,it will ruin your alternator. Than you will have to replace both.John is right dont use your alternator as a charger you will burn it out!!

soccerguy045
Aug 28th, 04, 12:58 AM
I guess I will have to do it when I get back to town, but I've no choice to make a 2 1/2 hour road trip before I do it :\

Thanks guys.

John_Muha
Aug 28th, 04, 1:05 AM
Is it sunny out? Can you find a cheap solar charger that plugs into the cigarette lighter? That will help a little while you are at the wedding. Otherwise bring jumper cables.

soccerguy045
Aug 28th, 04, 1:09 AM
That's actually a really good idea I didn't think of. I should probably pick one up anyway for the heck of it just to have.

Curious, what would happen if I had it sitting in the light on my dash plugged in while driving? Would that help charge the battery as I'm driving, or would that cause electrical problems and such? I'm not sure how it all works. Or is the thing really big and sits on the ground outside while a cord runs into the car? Not real sure. Thanks.

EDIT: Found some online, pretty cool and very reasonably priced. Probably a good idea to have since my car will spend a lot of time sitting in the parking lot not being started. Think Autozone or O'Reilly would have something like that?

John_Muha
Aug 28th, 04, 1:17 AM
Won't help much when driving. It can S L O W L Y charge a battery while sitting. It's best to keep a battery up while the car is sitting and you have no other means. This link work? They have a $10.00 one but not sure about it.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=38055

soccerguy045
Aug 28th, 04, 1:21 AM
Looks great. I will definately get one. Thanks!

HOTRODSRJ
Aug 28th, 04, 7:05 AM
John.....why do you remit that the alternator won't bring a battery back? If the battery voltage is less than the charging voltage the alternator will always crank amperage it's way as long as it will accept it? That's one of the functions of the battery it to recharge the battery if it's low. I have done this countless times?

I don't understand your statement I guess? I have had plenty of times where the cars alt recharged a battery left overnight with the dome lights on or etc?

NOw if the battery is disfunctional due to low water, or bad cells.....different issue.

Dean
Aug 28th, 04, 9:09 AM
Originally posted by HOTRODSRJ:
John.....why do you remit that the alternator won't bring a battery back? If the battery voltage is less than the charging voltage the alternator will always crank amperage it's way as long as it will accept it? That's one of the functions of the battery it to recharge the battery if it's low. I have done this countless times?

I don't understand your statement I guess? I have had plenty of times where the cars alt recharged a battery left overnight with the dome lights on or etc?

NOw if the battery is disfunctional due to low water, or bad cells.....different issue. Steve, why do you say "remit" ?

John_Muha
Aug 28th, 04, 9:55 AM
Guess you will have to do your own research Steve. A little busy today to do it for you. It's a mistake to think that an alternator will bring back a battery that has been drained or weakened.
Will the car start again after 25 miles of driving? 50 miles of driving?...I can't answer that. Though I have also prayed while starting a car.

JWagner
Aug 28th, 04, 11:32 AM
I have foolishly left my lights on for many hours and drained the battery and it charged up OK after a jump start and 30 minutes of running. There is the possibility that a battery that has been discharged for a period of time will not come back to life, no matter how much time it spends on a charger. At least that is my experience.

onick
Aug 28th, 04, 1:45 PM
so if you have your car on accessory every now and then while the car is not running, you are discharging your battery little by little and won't be able to get that charge back? How often should a battery be placed on a charger to stay healthy? Whats the best way to test a batt while its still in the car? VOM?

Peter F.
Aug 29th, 04, 12:18 PM
The battery will be recharged after a 2-1/2 hour drive. The alternator will be producing 14V which will charge the battery if given enough time.

I think the concerns doing this boil down to a few differnt issues.

A car battery really shouldn't be charged at a high current for a long period of time. It's generally considered hard on them and they generally don't charge as well as when slow charged. Jwagner also has it right that in that heavily discharging a car battery is bad for it too.

2. Having a dead battery on the alternator will draw a lot of current which is hard on the alternator. Now, I personally don't agree with this immediately killing the alternator because if you put electric fans and pump and such on the car you can draw the same current levels and the alternator will generally survive this treatment fairly well. If you do it once or twice the alternator will most likely survive.

Peter

dyno jonn
Aug 29th, 04, 2:55 PM
The ability of an alternator to charge a battery varies with the type of alternator. The older alternators put out fewer (37-63) amps than the newer internally regulated alternators. The 37-63 amp alternators will usually recharge a (healthy) discharged battery without melting down. The late model 100-140 amp internally regulated alternators should not be used to recharge a battery, they are only meant to keep a battery topped off. They are built with lighter components and have less ability to dissapate the enormous amount of heat they give off when they are making all those amps.

If you jump a late model car that has a bad battery you will probably melt the alternator, then replace the alternator, replace the battery, then replace the second alternator before the lesson is learned.
Let me tell you about my 87 Firefird. graemlins/clonk.gif

supersport396_2000
Sep 2nd, 04, 7:14 PM
The ole ford has killed the battery many times (draw) and i just push it off then go on my way.I never recharge.