battery dieing overnight?

[Black2011]

Since about 3 weeks ago my battery has begun dieing overnight, unless I put a charger on it. Progressively worsening, for about a week I had been boosting it and allowing the alternator to charge it (I know this is not good)

 

And after boosting, drove for 1 hour and shut off for 15 minutes and the truck would not restart.

 

After driving it all day, filled up with gas any by the time it was full "Battery low start vehicle" message was displayed.

I have an aftermarket installed remote start, however the place that installed it instructed me that turning the remote start into valet mode powers down the modules used to bypass security features (that may be drawing on the battery) and leaving it overnight or a few days would eliminate this as a problem. however, I have little faith in GM's warrantee and feel taking it to the dealership could leave me with a nasty repair bill on a truck I do not rely on as a daily driver... (I have a car as well, much cheaper on fuel)

 

I also do not want to replace the battery to find out it was worn out due to a warantable failure.

[txab]

Have you even tested the battery? Had the alt. checked for output?

[markw8]

Sounds like a bad battery.

 

Mark

[Silverado4x4]

Yup bad battery its not holding a charge or the alternator is not putting out have it checked. I have seen batteries last 2 years and some last 6 years on the same make and model.

 

Start the truck and leave it running then disconnect the battery if the truck dies then the alternator is shot.

[gmtech4]

take it in for warranty ,they WILL do a test with a hand held unit ,if it fails ,YOU GET A NEW BATTERY..

 

easy enough ?

 

and it will fail,,,,we know that rite now

[aflesch]

Just FYI this was my experience with GM battery warranty

 

http://www.gm-trucks.com/forums/index.php?showtopic=148743&hl=

 

Good luck.

[waumo1]

You need some troubleshooting to determine if it is bad battery, bad alternator, parasitic draw, etc. If you can't do that yourself, you need to take it to somebody that can.

[Black2011]

You need some troubleshooting to determine if it is bad battery, bad alternator, parasitic draw, etc. If you can't do that yourself, you need to take it to somebody that can.

 

I can, but I should not have too. I did test the battery, and the tester read `good battery, recharge` I work as a diesel tech so I have access to some equipment however I`m an apprentice so Im not a master mechanic by any means. its rated for 615 CCA and the measured CCA was 387? (weak charge)

This was after an overnight 20A charge, followed by sitting all day at work then driving home and back. Voltage output of the alt was 14.8-15v at idle, I did not load test it but I really doubt there is an issue with the alt. It may be a weak battery, but Im tired of gm finding excuses to not warantee issues. Unless there is a parasitic draw, this is just a failed battery. Anyone have steps to detect a parasitic draw? I use a snap-on manual multimeter for all my electrical testing so it should be fairly accurate.

One issue i need to address is testing the trucks battery life with the remote start disabled/powered down. I am not confident the valet mode it killing power to the units used for chip key bypass and anti theft bypass...

 

And I did not know batteries had warantee?! I assumed like tires, and wiper blades, your basically on your own, unless something obviously fails.

[waumo1]

Battery has the 3/36 warranty unless they have changed something. I agree you should not have to troubleshoot a new truck yourself but sometimes it is the only way.

 

I check the parasitic draw with a clamp on DC ammeter (hall effect, non contact meter). You clamp it around the easiest battery cable neg or pos. You must have it around all the wires going to the terminal. Then you wait and do not activate anything on the vehicle. If you have an underhood light, you need to take the bulb out.

 

If I remember correctly, the 2011 GMC took several minutes to reach full electrical shutdown whereas some other vehicles only take a minute or so.

 

You should end up with about 30-50 mA of parasitic draw. To discharge a good battery overnight, you would need to see about 4 Amps. A single bulb might be 0.5 to 1 Amp and will eventually cause problems.

 

If you have any aftermarket equipment - cell phone charger, radar detector, tuner, etc, suspect those first and unhook them.

 

For example, I found one cell phone charger that drew 200 mA even with the cell phone not attached.

 

Here is the meter I have: http://www.extech.com/instruments/product.asp?catid=26&prodid=77

 

 

Good luck.

[Black2011]

Battery has the 3/36 warranty unless they have changed something. I agree you should not have to troubleshoot a new truck yourself but sometimes it is the only way.

 

I check the parasitic draw with a clamp on DC ammeter (hall effect, non contact meter). You clamp it around the easiest battery cable neg or pos. You must have it around all the wires going to the terminal. Then you wait and do not activate anything on the vehicle. If you have an underhood light, you need to take the bulb out.

 

If I remember correctly, the 2011 GMC took several minutes to reach full electrical shutdown whereas some other vehicles only take a minute or so.

 

You should end up with about 30-50 mA of parasitic draw. To discharge a good battery overnight, you would need to see about 4 Amps. A single bulb might be 0.5 to 1 Amp and will eventually cause problems.

 

If you have any aftermarket equipment - cell phone charger, radar detector, tuner, etc, suspect those first and unhook them.

 

For example, I found one cell phone charger that drew 200 mA even with the cell phone not attached.

 

Here is the meter I have: http://www.extech.co...id=26&prodid=77

 

 

Good luck.

 

I'm going to have to buy an ammeter, its an attachment for my multimeter but its like 350$ from snap on, so i'll see if i can borrow one... like you said my first suspect was my inverter i use to charge my phone, but with all equipment off the truck it still die's.

the biggest pain for me regarging the battery warantee, is if i take it in, and the battery does not fail, the dealership will charge me their "diagnostic fee" even though it only takes 5 min, and its 150$ At the peterbilt dealer i work at, we reflash ecm's regularily for free. even if our pc-program is not connecting properly, (HD cummins use a j1939 connector called inline 6 in conjuction with cummings insite, and it is far from reliable..) But yet gm cannot do a simple check for free, or at least cheap.

 

Now if i detect a large draw, (IE 1-5A+) how do i go about narrowing it down? you said check draw to the "terminal" are referring to the bulk wires passing through the firewall? or to the bulk of wires entering the fuse box? This is time consuming and Im lacking space... (i usualy check my truck at the pete dealership after hours, however I'm attending trade school 2 hours away and my truck is at home, supposed to be there incase my wifes car has an issue, however, its not proving any more reliable than her 04 chev optra...) Tomorrow Im headed back to school, I come home most weekends, and while I am capable of continuing testing Im not a fan of spending the little time I get with my wife working on my truck, which costs me 600$ a month and I cant even rely on.

[SILVERADOSC540]

With all due respect, it would seem to me that your chasing the problem rather than letting the pros due it for you. Why spend 300 dollars on a meter you've not needed instead of a diagnostic and resolution? Your time is worth money and time with family is priceless. Shop around and find a free diagnostic, then spend some money on the truck and some time with the wife.

[waumo1]

Are you out of warranty?

 

I didn't notice the part about the aftermarket remote start. Did the problem start shortly after this remote start was installed?

 

If you are under warranty and can eliminate the aftermarket equipment as as cause, take it to the dealer and leave it over night and let them find it dead or take it back to the people that installed the remote start and ask them to unhook it until you solve this problem.

[Black2011]

Are you out of warranty?

 

I didn't notice the part about the aftermarket remote start. Did the problem start shortly after this remote start was installed?

 

If you are under warranty and can eliminate the aftermarket equipment as as cause, take it to the dealer and leave it over night and let them find it dead or take it back to the people that installed the remote start and ask them to unhook it until you solve this problem.

 

 

No, I have 34000km on the truck, and I purchased 5 year 100,000km extended warantee when I bought the truck new, 17 months ago. I put the remote start in almost immediately after purchasing. (within 6 months)

 

The company that installed the remote start advised I leave the truck in "valet mode" which according too them disables the remote start system, and if it was the cause of the draw it would stop killing the battery. It had no effect.

 

I retested the battery last night and it failed. I used an "Intellect EXP HD" tested, which we use to test all our batteries for warantee purposes. the battery was reading 422 CCA (vs the 615 CCA rating)

I also checked the alternator, which is charging 14.8-15v and putting out 58-60A with all lights and fans on. (normal)

I used a general amp clamp to check for draws off the battery, which measures down to .1A and it reads 2.5A immediately after key off, and aprx 60 sec following drops to 0.0

Im going to assume this means I have a faulty battery, and If GMC warantee's the batteries like some say, I will get them to test it and replace it. I will have to do this next week as I leave my truck at home while im away for school and only come home on weekends.

[Black2011]

Battery draw after key off for 2 min

 

Alt output w/ accesories on

 

Voltage Key on engine off

 

Voltage key on engine running

[gmtech4]

please read post #5 again

 

they use the fail code from the tester and .....poooof ,you get a new battery