Charging the battery from engine idle... how long?
#1
Melting Slicks
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Charging the battery from engine idle... how long?
I haven't driven my vette in a while so I want to idle the engine in my garage to make sure the battery doesn't die. How long do I need to leave the car on, and is it safe to let it idle unattended?
#2
Team Owner
Run it arround or get a tender.
My car is away for the winter I have a Schumacher battery tender on it.
#3
Melting Slicks
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Sadly a tender would not work for me as I do not have a electrical outlet in my garage, and it is not connected to my house.
#4
Team Owner
#5
Safety Car
#7
Burning Brakes
If your battery is really discharged then running your car at idle could take a half hour or more and that probably not the best thing to do for your charging system. A word of caution here is not to let your car over heat and don't run it in a closed garage. If you're just keeping the battery topped off, then 10 minutes at idle should do the trick. I have a couple of classic cars and I start them every couple months and let them idle for about 10 minutes. It keeps the battery charged.
Although running at idle will work if not done for too long, its better to just take a short 10 or 15 minute drive to charge the battery.
Finally, the best way for you to keep the battery up would be to use a tender. I don't know how far your garage is from your house but there are some very long extention cords available that I bet you can run out to the garage.
Although running at idle will work if not done for too long, its better to just take a short 10 or 15 minute drive to charge the battery.
Finally, the best way for you to keep the battery up would be to use a tender. I don't know how far your garage is from your house but there are some very long extention cords available that I bet you can run out to the garage.
#8
You'll get almost no charge at idle. If you don't have full-time power in the garage use a battery charger on an extension cord for a few hours once a month or so, or remove the battery and bring it into a warmer space.
The C6 will run the battery down just sitting; about a month is the longest it should go without being driven or charged.
The C6 will run the battery down just sitting; about a month is the longest it should go without being driven or charged.
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I have no idea if this would work or not but... do you know those portable battery chargers (the ones that Triple A use) I wonder if you would be able to charge one of those up once a month unplug it head to the garage hook up the vette and "charge" up the battery using that device????
Again I have never done this or researched this and I personally would try to run the long extension cord into the garage as my first option.
Again I have never done this or researched this and I personally would try to run the long extension cord into the garage as my first option.
#10
You'll get almost no charge at idle. If you don't have full-time power in the garage use a battery charger on an extension cord for a few hours once a month or so, or remove the battery and bring it into a warmer space.
The C6 will run the battery down just sitting; about a month is the longest it should go without being driven or charged.
The C6 will run the battery down just sitting; about a month is the longest it should go without being driven or charged.
Note, the alternator is rated at 90 amps (at 6,000 RPM), but there's no way you can charge a lead-acid auto battery that fast, it'd explode. 30 amps is a fast charge for a car battery. So starting the car and letting it idle for short periods will simply further deplete the battery since it won't have charged fast enough or long enough to even make up the charge you used to start the engine. If you can't drive it, remove the battery to a warm location and keep it on a charger.
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Last edited by cthusker; 12-04-2007 at 12:58 PM.
#12
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The alternator doesn't put out much current until the engine is turning at least 1500 RPM. With all the normal electrical loads in the car, at idle you'll be lucky to get 6 amps for battery charging. That means it'd take 11 hours at idle to charge a run down 65 amp-hour battery. Kick the RPMs up where you can get 30 amps charging current, and the battery will recharge in 2 hours.
Note, the alternator is rated at 90 amps (at 6,000 RPM), but there's no way you can charge a lead-acid auto battery that fast, it'd explode. 30 amps is a fast charge for a car battery. So starting the car and letting it idle for short periods will simply further deplete the battery since it won't have charged fast enough or long enough to even make up the charge you used to start the engine. If you can't drive it, remove the battery to a warm location and keep it on a charger.
Note, the alternator is rated at 90 amps (at 6,000 RPM), but there's no way you can charge a lead-acid auto battery that fast, it'd explode. 30 amps is a fast charge for a car battery. So starting the car and letting it idle for short periods will simply further deplete the battery since it won't have charged fast enough or long enough to even make up the charge you used to start the engine. If you can't drive it, remove the battery to a warm location and keep it on a charger.
#13
Your 07 coupe should be fine for several weeks at a time. I would suggest a battery tender, which come with eye connections that you can leave connected year round. These plug in and out to the actual tender, that you only need to connect, maybe once a month, to stay at peak battery. So move it once a month, to power supply, leave connected and covered early a.m. to late evening, and tender should give you a green light to show full peak. Put back in garage for 4 to 6 more weeks. Az. must be nice. Good Luck
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If you can't get electricity to your battery, take your battery to the electricity. Remove it and put a charger on it in the house.
#16
Safety Car
The car will charge just fine idling for a half hour or so. It's not as good as a long drive or using a charger, but it will charge the battery better than doing nothing. I've worked at several dealerships where the used car dept will start all the cars on about a weekly schedule and let them run for a half hour or so. We even left the parking lights on so we knew which ones were running. That worked great, the batteries stayed charged. If we just let the cars sit, many batteries would go dead. Once we started the weekly idling every car, no more battery problems.
#20
Safety Car
I think he wants any easy way to give the battery a charge, which idling it for a while will do just that. No it's not ideal, yes removing the battery, taking it somewhere else to charge would give it a more complete charge. But, a quick an easy boost and save the hassle of messing with removing the battery is to just fire it up and let it run.
Want to prove to yourself the battery is charging, watch the DIC voltage before, during, and after, it's getting a charge. Idling it doesn't hurt a thing, I've let cars idle for long times countless times, nothing bad ever happened. Your probably going to want to do this every so often. Who would want to remove the battery every time.
Fire it up, just make sure the tail end is outside so fumes don't build up in the garage.
Want to prove to yourself the battery is charging, watch the DIC voltage before, during, and after, it's getting a charge. Idling it doesn't hurt a thing, I've let cars idle for long times countless times, nothing bad ever happened. Your probably going to want to do this every so often. Who would want to remove the battery every time.
Fire it up, just make sure the tail end is outside so fumes don't build up in the garage.