Sebastianc2012

So for the past month or two, my jeep has had a problem starting and holding a charge.

It started as the truck sometimes needing to rev for a few seconds before turning over, but it progressively got worse, and the truck battery would die weirdly fast.
Now the battery will die after having the door open or lights on for 5-10 minutes if the truck isnt already running.

The only way i could get the truck to start half the time is to rev the engine for 5-10 minutes and try again, unless i had recently driven it a good distance, it would start right up.


Yesterday when trying to start it, i just got clicking, and really dim inside lights, i charges it from another battery for maybe 5-10 minutes. After detaching the jumper cables, the truck started fine, and i let it isle for a minute and then turned it off and it was dead again in 20 minutes.


Is this a bad battery or something else entirely? Ive had the battery for about 3 years.

kjc

Check the battery voltage with an accurate voltmeter. It should read 12 volts or higher.. no lower than 12. Now start it up and check the voltage at the battery at idle. It should read higher while it's running as you are now measuring alternator output. Rev the motor to a steady 1500 rpm and see if the reading is around 14 volts. If it's not 13+ volts while running, you probably need a new alternator.

Crash_Course

Another consideration: check the individual cells on your battery, a battery can have one bad cell and still masquerade as taking/having a normal charge. I had this exact issue in March on the year-old Duralast (autozone) battery my XJ came with that was exhibiting many of the symptoms you described. A nice new bright green Interstate solved all my issues.

Sebastianc2012

Manage to tow my truck up to AutoZone and have them test it, said it was the battery and I luckily had a month left of warranty so I got it replaced for nothing, although not the best I could have gotten, can't beat the price

Pelican

What do you mean "rev for a few minutes before turning over"?


You cannot charge a battery in 5 to 10 minutes.


You should get a proper charge (say overnight) and then have the battery load tested at a shop.


Edit: Glad you found it. Still curious what you mean by revving before turning over.

Sebastianc2012

I'm probably using bad terminology, my truck wouldnt start up unless I gave it gas, and would die right when I let off the gas, but if I sat there giving it gas for 5 minutes, and then tried to start it up, it would sometimes start up and stay running

Crash_Course

This is precisely what mine would do, it's a result (I'm told) of the ECM loosing the calibration for the Idle Air Control Valve after battery voltage loss. It would "re-learn" the settings and then the battery would get dragged down and start the entire process all over again. Glad you got your battery swapped. Mine probably had some warranty left on it, but I really dislike our auto zones here plus I've always had fantastic results with Interstates.