High Idle after jumpstart
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From: West Chester, Pa
High Idle after jumpstart So I don't use my car very often because I have a take home work vehicle and the battery dies pretty quickly in this cold weather.
I connected a charger to it for a couple hours at 40amps, at first it stalled out, and when I started it again it stayed running, but the idle was high, around 1500rpm, even after warming it up and driving around for a bit.
What's going on? was the battery still weak and the engine was revving higher to try to recharge it? I was thinking since the battery died the ecu had to relearn proper idle and that's why I drove it around for a bit, but it was still idling high when I pulled back into my driveway. I have the charger hooked up to the battery again on slow charge and am going to come back later and see what happens. Thanks for any input.
I connected a charger to it for a couple hours at 40amps, at first it stalled out, and when I started it again it stayed running, but the idle was high, around 1500rpm, even after warming it up and driving around for a bit.
What's going on? was the battery still weak and the engine was revving higher to try to recharge it? I was thinking since the battery died the ecu had to relearn proper idle and that's why I drove it around for a bit, but it was still idling high when I pulled back into my driveway. I have the charger hooked up to the battery again on slow charge and am going to come back later and see what happens. Thanks for any input.
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From: Schiller Park, ILL Member: #317
Even if the weather is cold, very cold (it was -8°F here this morning), a healthy battery with a proper charge shouldn't die pretty quickly. We have two daily drivers that sit outside in this weather, one of them doesn't get used too often but it'll still fire up after 2-3 weeks even in this cold. If your battery is dying quickly, then I suspect that it's either old/bad, or it's not getting enough of a charge when you DO drive it.
Second, charging any battery for a couple of hours at 40 amps is excessive. Most home chargers will give you a short burst of up to 50 amps for a jump start, but then only charge in the range of 2-10 amps depending on settings and charger type.
Third, if the battery was truly dead then the PCM will in fact have to relearn all the soft parameters. You might have some idle weirdness at first, but it shouldn't be stuck at 1500rpm for a long period unless something else is going on. Regardless, the condition of your current battery is likely questionable.
Second, charging any battery for a couple of hours at 40 amps is excessive. Most home chargers will give you a short burst of up to 50 amps for a jump start, but then only charge in the range of 2-10 amps depending on settings and charger type.
Third, if the battery was truly dead then the PCM will in fact have to relearn all the soft parameters. You might have some idle weirdness at first, but it shouldn't be stuck at 1500rpm for a long period unless something else is going on. Regardless, the condition of your current battery is likely questionable.
Thread Starter
Teching In
Joined: Jun 2014
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From: West Chester, Pa
Even if the weather is cold, very cold (it was -8°F here this morning), a healthy battery with a proper charge shouldn't die pretty quickly. We have two daily drivers that sit outside in this weather, one of them doesn't get used too often but it'll still fire up after 2-3 weeks even in this cold. If your battery is dying quickly, then I suspect that it's either old/bad, or it's not getting enough of a charge when you DO drive it.
Second, charging any battery for a couple of hours at 40 amps is excessive. Most home chargers will give you a short burst of up to 50 amps for a jump start, but then only charge in the range of 2-10 amps depending on settings and charger type.
Third, if the battery was truly dead then the PCM will in fact have to relearn all the soft parameters. You might have some idle weirdness at first, but it shouldn't be stuck at 1500rpm for a long period unless something else is going on. Regardless, the condition of your current battery is likely questionable.
Second, charging any battery for a couple of hours at 40 amps is excessive. Most home chargers will give you a short burst of up to 50 amps for a jump start, but then only charge in the range of 2-10 amps depending on settings and charger type.
Third, if the battery was truly dead then the PCM will in fact have to relearn all the soft parameters. You might have some idle weirdness at first, but it shouldn't be stuck at 1500rpm for a long period unless something else is going on. Regardless, the condition of your current battery is likely questionable.
So after running it for about 10-15 minutes I hooked the charger back up to it on slow charge, and the light is no longer green. It's orange telling me that the battery is not fully charged. It's been about 20 minutes now and the light still hasn't gone back to green. I would expect the light to be green right away telling me the battery is full after charging all day and letting it run for 15 minutes. The only reason I could think of why it would have to charge up for a bit again would be if there was a problem with the charging system/alternator. Seems to me like it's not doing a good enough job recharging the battery? Is this a reasonable conclusion?
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hey I just thought of something else that did happen to me not to long ago , the negative battery post had gotten corrosion on it and so it wouldn't except a good charge and then also didn't put out a strong signal to the electronics in the car, in the form of volts ! It did start but ran a high idol , turn car off cleaned both posts, started it up , everything back to normal ! hope this helps .
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Thread Starter
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From: West Chester, Pa
Yeah, I just did the headlight test to see if maybe it was the alternator. I didn't see the lights dim or flicker at all when I tapped the throttle. So the problem must be the battery.
The posts looked pretty good on my battery but I will try cleaning them and seeing what happens. Thanks.
The posts looked pretty good on my battery but I will try cleaning them and seeing what happens. Thanks.
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Verdad Gallardo Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
If the terminals are clean (inside and out) and on tightly, then I would suspect that the battery has seen better days and should likely be replaced at this point. Doesn't seem like it's taking and/or holding a charge properly based on everything mentioned so far.
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I would agree with RPMWS6 , the battery being the suspect . If you can start car, & have a multi - meter put blk. probe on neg. post of battery & red probe on posi. post of battery , set multi - meter on "dc volts" , and it should read about 14 volts if alternator is working . What's the voltage of battery without charger on it , and then check it 1hr. later , and 1hr again check it . then you don't have to start it to check it , and if you note a continual drop of voltage , remembering that your car needs a good 12.30+ volts min. to start , you've just figured it out , which one is bad ! Good alternators & batteries aren't cheap so be sure which one is the bad boy, before buy'n both ! ok ..... !
This is the time of year where weak batteries get exposed, so if your battery is over 5 years old, it's probably worth changing it out - no matter if it tests "good" or not. Even if your problem is elsewhere, you are on borrowed time with that Die Hard.
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From: West Chester, Pa
First step is to find out. All batteries have their birthdate on them:
https://www.youtube.com/watch?v=BT_UzRpcPYg
This is the time of year where weak batteries get exposed, so if your battery is over 5 years old, it's probably worth changing it out - no matter if it tests "good" or not. Even if your problem is elsewhere, you are on borrowed time with that Die Hard.
https://www.youtube.com/watch?v=BT_UzRpcPYg
This is the time of year where weak batteries get exposed, so if your battery is over 5 years old, it's probably worth changing it out - no matter if it tests "good" or not. Even if your problem is elsewhere, you are on borrowed time with that Die Hard.
http://www.sears.com/ue/home/diehardfaq.html#03
"How do I determine the age of my battery?
A decal placed on the side of all DieHard batteries provides the month and year each battery was shipped from the plant. The letter corresponds with the month, starting with “A” for January, “B” for February etc. The number represents the year with “7” standing for 2007. For example, A/7 would be January 2007."
At any rate it's looking like I need to replace the battery.
Last edited by Grusselgrosser; Jan 3, 2018 at 07:52 PM.
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From: Schiller Park, ILL Member: #317
Regardless, I would replace it if it's not properly taking or holding a charge. FWIW, in regards to my post from yesterday, our spare daily driver just sat outside for two weeks, unused, in temps ranging from -10°F to about +15°F, and it fired up and ran just fine today. They shouldn't dump a charge in a week or two, even in this cold, unless the battery is weak, poorly charged to begin with, or there is a drain somewhere (which is somewhat typical for certain new cars even if nothing is "wrong", but not with 4th gen F-bodies.)
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So it sounds like you should replace the battery especially since it's not holding a charge and the birthdate from the battery is older than the warranty of the battery. I just had 2 cases were the batteries dates said that they were good till February 2018 and after testing both batteries I found that they were both junk. So testing and knowing your birthdate of your battery are important factors in deducting if your battery is bad. Like to know how it endeds up , so keep us updated.
I would echo RPM Ws6's comments. We do have other threads about batteries, which have gone this long.
I suppose it all depends on what your personal situation is, what access you have to a jump, and your exposure to getting stranded from a bad battery.
If you have a $100, 7 year battery in it's 6th year of life, it's depreciated to being "worth" $12 at that point. Consider the increasing risk of getting stranded on top of that and one should be able to make a decision.
If you have a $100, 7 year battery in it's 6th year of life, it's depreciated to being "worth" $12 at that point. Consider the increasing risk of getting stranded on top of that and one should be able to make a decision.
Thread Starter
Teching In
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From: West Chester, Pa
"How do I determine the age of my battery?
A decal placed on the side of all DieHard batteries provides the month and year each battery was shipped from the plant. The letter corresponds with the month, starting with “A” for January, “B” for February etc. The number represents the year with “7” standing for 2007. For example, A/7 would be January 2007."