Battery Drain

[guruerror]

Here and there I've seen threads about dead batteries and parasitic drains but none mention what I've discovered and I thought I'd through this out here to get your thoughts.

I've notice that if I leave the rear hatch open for an extended period of time (4 or more hours) the battery will drain so low that I cannot start the truck. The first time this occurred I assumed that the interior lights must have been on the entire time and that they were the culprit, but the interior lights don't stay on for the whole time...they turn off after a few minutes to guard against a battery drain when a door is accidentally left ajar.

SO...if the lights turn off automatically WHAT would continue to drain the battery when the rear door is open.

This has happened to me at least three times...so now I'm overly conscious of leaving the door ajar, but thought I'd mention it in case someone had a thought on how to resolve...or where next to look.

[2010_5thgen]

ive never left my door open for 4 hours, but the only thing that comes to mind would be something blinking on the dash telling that the hatch is open? i dont even know if our trucks have that but i know escalades and tahoes do. but thats would be alot of blinking to run down the battery. the little red sensor for the alarm gets more blinking action at night than the door adjar light would. maybe you have a weak battery?

[guruerror]

Yeah, my battery has seen better days. It's about three years old and has been completely discharged several times; but, still, even if we had an indicator light it shouldn't drain a car battery in 4 hours...even an old, tired one.

There just seems like there's something more to it than a weak battery.

[[__--MUD--__]]

The BCM directly controls all the interior lights to prevent battery drain. Everything should be completely shutoff by the 15 minute mark. By 20 minutes the BCM should be asleep. If you have not done any modifications on the truck since or recently before this issue has started-

Take your **** down to a couple different parts stores and have them test your battery. Note I said couple. My past experiences have shown you dont know if their equipment is working properly or if the employee knows what the hell they are doing. I'm betting your battery is ****.

I had a bad cell or two on my optima. I had that battery tested 3 different times at my usual place, tested good every time. Second store the 4th time said my battery was **** right away. I could go for weeks, hours, days between issues. Completely ****ing random. Go in a store for 45 minutes and have a dead battery, then the damn thing would be fine for days or weeks again.

I'd almost be willing to be you a six-pack thats your issue. Dont buy a yellow top optima, they're not built like they used to be. I've had zero issues w/ the newer red tops.

[2010_5thgen]

plus the cold weather plays part in draining even a good battery. i like optima red tops. i had them in a few cars of mine. and my god, please dont go to walmart. i went there for my plow truck battery. a buddy of mine swore by these batteries there that they were the best. well they might have been good, but they let the janitor install them....not literally but they allow anyone to do that stuff there. well, they installed this new battery for me....my truck was dead before i left their parking lot. freaking idiots didnt tighten down the cables. so i had them put a new one in after fighting with them for 3 hours.

[guruerror]

I understand how weather can be a factor, but it doesn't seem to be part of this equation...I only have the hatch open like that when I'm cleaning/working on the truck or working on something else (that's where I keep my tools) and that's usually only on nice, sunny days. The only reason I even had the thought to post this today was that I was swapping the battery out this weekend and I thought..."don't forget to start that battery thread."

I dropped in a YellowTop D31A...we'll see how it goes.

[[__--MUD--__]]

so pop your hatch and come back in 5 hours