Dead Battery

[Great8]

Went to start my SRT this morning it almost turned over but went click,click,click. I have noticed it only charging between 13.4 and 13.8 its an 06 it seems the 07's and 08's charge at 14.1 to 14.6. Might just be time for a battery. I drove it last night with lights and radio on charging was all over the place from 13.2 to 13.4 down to 12.9 back up to 14.0. So I dont know whats going on. Any thoughts? Thanks

[bigjim]

Clean all the points (battery terminals, altornator connection, battery ground and engine ground), then see what it reads. Then get a load test at any shop and see what the alternator puts out.

[Great8]

I cleaned all connections and had it on a trickle charger all day. It just went to green on the charger so I started it up, no problem ,read 14.0 at first then dropped down and was holding at 13.8, seems the 05 and 06 charge between 13.4 and 13.8 from what I've seen. I did check IOD it is at 12.4 when everything powers down and still at 12.4 the next morning. Today was the first day it read 12.4 but wasnt enough to start.

[bigjim]

Did you check electrolyte level? Sounds like no capacity. See what the voltage drops to during crank as well.

[fnkychkn]

since it takes much higher voltage to charge a cold battery than a warm battery, the PCM regulates system voltage as a result of calculated battery temperature. the colder it is, the higher the regulated voltage, the warmer it is, the lower the regulated voltage.

at low RPM/idle speed, system voltage will also be inversely proportional to system load because the A/C generator cannot provide full output at low RPM.

[Great8]

Its hard to see an exact number but looks like on startup it drops below 10 volts. I dont have a hydrometer (I think thats what they were called) to check electrolydes. If it starts tomorrow I'll run it up to the dealership the alternator is under ext. warr but battery is not . 46,000 miles on the car. Fnky are you saying that voltage fluctuation is ok?

[fnkychkn]

Fnky are you saying that voltage fluctuation is ok?

voltage fluctuation is inevitable.
how long was the car sitting before you tried to start it? (when it wouldn't start)

[Great8]

It sat in my garage over night. I checked voltage after everything powered down it was 12.4 and checked again before starting this morning still at 12.4. So no IOD. But just didnt turn over. Wife said the day before was hard to start for her also.

[Great8]

Fnky what I meant about the voltage fluctuation was I had not seen drop to 12.9 volts before it was kind of all over the place. I was thinking when I washed the car a few days ago I always open all the doors and trunk to clean the interior and have the radio on takes me about 20 min it wouldnt start when I was done. I waited 10 min then it did start

[fnkychkn]

battery may just have been weak. should be OK now that it's fully charged.

[Great8]

Thanks Fnky, We'll see if it starts in the morning.

[Great8]

I give, decided to try and start it tonight one more time, EVIC shows 12.4 but would not start just click, click, click. Guess I'll let the dealer check it tomorrow.

[Great8]

Just wanted to update fellow members; I replaced the battery and all is fine, charging between 13.8 and 14.0. Its too bad some of us have bad battereies at only 3 years. Thanks again for everyones input!

[mills]

LOL - Mine didn't last 3 months.

[TorRed #1179]

Don't feel bad. Mine died this winter as well, of course the culprit was all those track days with the fans running on high.

Replaced the oem battery with a Yellowtop Optima. However, even on these cold nights, it still doesn't hold a charge very well. Had to go out tongiht and put it on the charger overnight. Pretty sad paying $200 for a battery that I still need to charger overnight. Should have just let the dealer replace the oem under warranty!