Battery Drain & Low Voltage

[FlyboyTR]

Since purchasing the 02 Kon XL, I have noticed that it seems a bit weak in the cranking department. My radar detector screams low voltage when cranking the engine; after sitting for several hours. My first find was both battery cables were not tight. I removed and cleaned everything and reinstalled them. No change in performance. I've had two shops put it on their machine and everyone agrees both the alternator and battery are fine.

With the engine running at idle I have 14.2 to 14.8 volts. At idle and using my 100 amp load tester, idle voltage will drop to 13.4. All of this is acceptable. After sitting overnight, my static voltage is 11.8 to 12.2 volts (checked several times). From my experience this is too low.

The Kon has now been sitting for 5 days, waiting on my new HVAC blend door servo. So...I decided to start checking the battery. Voltage was 11.6 and with the 100 amp load test it would drop to 10 volts. ...not happy. I disconnected the negative battery cable and put a digital amp meter in line. The following is with the drivers door open, no gadgets connected, etc; so other than internal computer drain there was nothing else, except the dome lights:

6.8 amps
2.68 amps after closing door and dome lights going out
1.5 amps after 15 seconds
0.9 amps after another 10 seconds
0.12 amps after another 10 seconds...and it stays there.

Doing a retest without the dome lights, it started with an approximate 2.68 amp draw (same as it was after the dome lights went out). I repeated this test several times; same results. 0.12 amps is nothing for a static draw on a system and should not effect battery performance for a month or so with a solid battery.

I put my big electronic battery charger on the battery and it was showing 11.8 volts, almost identical to my analog 100 amp load tester. After it tested the battery it showed the battery charge level at 45%. Very low! I currently have the battery disconnected and on a 2 amp (slow) charge. I will check it later this evening and if it has charged fully, I will disconnect the charger and let it sit (not connected to the vehicle) and then do a load and voltage test later tomorrow. If it has dropped, I believe I have confirmed the battery is not holding a charge. Surface charge on a battery can be very deceptive!

Sorry to ramble on...but just wanted to throw it all out there. Any other thoughts or suggestions would be appreciated. Thanks!

 

[Wake]

Had an electrical drain on my Escalade that drove me nuts till I found it, probably took about a month. It wasn't as subtle as yours though. Mine would drain overnight, or very quickly (2hrs) when hot, nearly left me stranded away from home a few times.

In my case it turned out to be the starter having an internal short somewhere. Not enough to get hot to the touch on a cold engine, but enough to kill the battery.

I replaced my starter and haven't had a battery issue since, 1 year now.

In your case, I wonder if the current draw grows after it sits awhile? I wouldn't think a 120mA draw from probably the theft/security system would be the culprit. Also, I wonder how long it takes the body computer and other systems to shut down after the key is removed and security system is set. If you can't find anything wrong with the battery or alternator and your draw after a couple of minutes is only 120mA, I would think something is coming on later after it sits.

Any aftermarket electronics installed, chargers plugged into the rear or console plugs?

 

[FlyboyTR]

Any aftermarket electronics installed, chargers plugged into the rear or console plugs?

Wake,
Nope. Nothing plugged in other than the radar detector and it is wired through my mirror circuit; so it's only hot when the key is on. I also unplugged my ScanGuage while testing. It actually had a static draw of 0.09 amps.

If the battery tests low/weak in the morning, it is now off the charger, I may try the Epsom Salt trick and see what that does. We're leaving in 11 days for an 8 day skiing trip; so whatever I do, I've got to have some confidence in the battery...and that may mean a new one!

 

[Rivieraracing]

Sounds like you have some good ideas Travis, keep at it and keep checking in with your progress!

---------- Post added at 08:34 PM ---------- Previous post was at 08:30 PM ----------

If your battery ends up needing to be replaced, get one of these! I've had mine for 2 years and my truck starts up effortless unlike the one the truck came with!

http://www.interstatebatteries.com/..._Yukon+XL+1500|2002_Standard+Battery_V8/6.0L)

 

[Red Rider]

The battery is clean right? i have heard of slow drains from dirty battery where crud and grim creates electrical short and drains the battery between the + and - terminals. I think i have a slow battery drain too. I was suspecting the cluster. cluster got better after I took it apart and since, it has been better, but battery has suffered. I need to load test it.

 

[ccapehartusarmyINF.(ret)]

just get a new battery clearly the one you have is pretty old and do not get an interstate before i bought my tahoe off my perents they used interstate batteries and they went thru an interstate battery every 1 -2 years
personally ive never had an optima go bad i was gonna try kinetic but alotta people say those are over priced and overrated

 

[FlyboyTR]

Red,
As noted in my OP, after finding the battery cables loose, I cleaned everything. You're right...that is always a good place to start!

Ccape,
A new battery may be the correct option. However, before spending the money "I" have to be convinced that the battery is truly failing. There are shorts, etc that can come and go, as Wake pointed out in his post regarding is starter. We had a conversion van a few years ago that had battery problems and replaced the battery three times in about 6 months!!! One day I walked past the van and heard something running. I opened the door and the HVAC fan (front and rear) was running! When I got in and closed the door, they shut off! After lots of searching I finally found some worn/exposed wires next to one of the HVAC relays. When it would short, it would activate the relay and run the blowers at whatever speed the controls were set at! CRAZY!

I will be checking on the battery status a little later this morning to see if it has lost power overnight, disconnected from the vehicle (that will rule out any normal or abnormal parasitic drain).

---------- Post added at 10:37 AM ---------- Previous post was at 09:27 AM ----------

The battery tested at 80% this morning and 12.2 volts. After two 10 second load tests (100 amp), the static voltage dropped to 11.8 volts and showed 400 CCA under load (that is ½ of its rated 800 CCA). Retested with the charger and the % of charge was now at 50%. It’s new battery time.

I am going to try the Epsom Salts battery saver trick and see what happens (I have another old battery I can use for the core charge on the new one). I may post a thread on the results. It seems like a lot of people are using this process. However, I don't think I would trust a "fixed" battery in any of our family vehicles; may be a good shop battery to have around.

Thanks again for the input...appreciated.