YACT: Bad Battery causing stalls?

[Garion]

I've got a 97 Jeep Grand Cherokee (V8, auto) that has been acting strangely lately. I've got a suspition that it's a bad battery, but wanted to get a few other opinions..

When we don't drive the Jeep for a few days, it turns over very slowly when you first start it up. It will eventually start (after about 5 seconds) but it's definitely NOT normal. Another symptom: The clock is flashing and needs to have the AM/PM and day/date reset after you start it.

When it's in this mood and you get it started, it acts very strangely. It seems to run fine, but it doesn't idle - If you let the RPM's drop down it will stall out instead of idle. Needless to say, this makes stop signs fun, especially with an auto. It will even occasionally die going down a hill.

If you drive it for ~15 mins, it will stop stalling. If you stop and re-start, it will start hard, but the stalling will be gone. If you drive for about 40 mins total, everything will be back to normal and it will start right up.

I did an experiment and put a battery charger on it after we hadn't driven it for 4 days and it started right up, no problems.

This is my wife's car, the one that she hauls the kids around in. If it were me, I don't mind too much - I can muscle the brakes and steering without a lot of effort when there's no power assist but I'm concerned about it causing her problems if it dies at a bad time.

This smells like, feels like a bad battery, but we had it tested at the local mechanic (Who is OK, but not great) and they said it was fine. I don't necessarily trust them totally, however. I got the battery at Costco about a year ago, so it's still under part of it's 3 year warranty, so if I have to swap it out it's not the end of the world.

Any feedback would be much appreciated!

- G

 

[thomsbrain]

well you clearly have some voltage problems. i'd swap the battery, for sure.

 

[95SS]

Change the battery, and have the alternator and voltage regulator checked. A bad battery left for too long will kill other electrical parts.

 

[Insane3D]

Sounds like the battery...but once you start it, it shouldn't be using the battery at all. It might be the alternator/voltage regualtor as was already stated above..

 

[sao123]

battery = bad.

 

[davew0670]

I just had the same problem with my 96 jgc. took the battery to get tested and it was fine. I checked the connections and cleaned all the battery cables and posts and it hasnt happened again.

 

[zixxer]

more than likely your mechanic just tested the voltage reading of the battery... not the cranking amps.


Swap the battery out, see if you still have problems

 

[TwoBills]

check your electrolyte levels using a hydrometer. Top w/distilled water. Clean/grease the terminals.

Here's a link autoshop101

 

[Rogue]

Start engine, remove battery. If the engine continues running, there's a good chance it's just your battery. If not, you'll need to replace battery and alternator.

 

[drnickriviera]

Originally posted by: Insane3D
Sounds like the battery...but once you start it, it shouldn't be using the battery at all.

That's what I though until I had a problem with my ram 2500 diesel. Both batteries were dead so I jump started it. Started to drive off, but anytime I used anything electrical (turn signal, brakes) the engine would die. Alternator was fine, just 2 bad batteries.

I could never figure out why a diesel of all engines would require batteries to run.

 

[MaxFusion16]

it's the battery, the exact samething happened to my buddy's car.
the car won't idle and stall when stopped.

 

[nwfsnake]

If the batteries plates have shorted, you have less voltage available even with the alternator running. Many cars can run OK (somewhat) with two plates shorted, but usually more than that and it will not start or run properly. Newer cars with all the electronic controls and computers are especially suseptable.

 

[dud]

The battery relies on the alternator for charging. Before you blame the battery check the output voltage from the alternator. This can easily be done with a cheap dignostic tool OR you can remove the alternator (easy) and bring it to the auto parts store to check.

My wife's Mazda was having problems starting, etc. so I removed the alternator & took it in. The output voltage ran someting around 10-11 volts when around 13.5 is normal. $125 and an hour later and the problem was corrected.

Good luck ...