1997 GMC Suburban K1500, 5.7L gas
TL;DR - 18 moth old battery dies in 4 days. 0.02 amp on parasitic drain test
I've been dealing with this issue for a while now. Battery is about 18 months old. If I let the truck sit for about 4 days, it does not have enough power to start. This has been going on for months now. I've done a parasitic drain test at least 3 times. Each time it spikes to around .8 amp for about 10 seconds then drops to .02 amps and stays there. If I test the battery after driving or charging, it still puts out 800-1000 CCA.
A couple of other thoughts / notes...
I did have issues with water leaking in through the windshield. I believe I fixed the issue, but the leak has broken the compass on the mirror and the buttons on the right side of the radio do not work. I consider the radio suspect.
I have a key fob with remote lock, but I do not keep the keys close enough to activate the locks.
When the doors are open, the lights draw about 3 amps. They are on a timer to shut off about 30 seconds after all the doors are closed.
I've been working on a device that will email me if the voltage drops (since last reading or below a threshold), but I haven't had much success as the lighter socket will put out 11.5v, while the battery is at 12+. I might try hooking this directly to the battery next. I know I still have some bugs in my code that I need to work out.
My method for parasitic drain - Disconnect the negative side of the battery and connect a multimeter set to 10 amp between the battery and the negative cable. Open/close the doors. I've turned the ignition on and off, thinking there may be some draw after the truck has shut down.
The voltmeter on the dash says the alternator is putting out 14v. A little higher after I have to jump it.
There is nothing aftermarket on the electrical system. No winch, lights, etc., currently nothing plugged into the lighter
If I can determine the battery is the issue, I will see about getting a replacement under warranty. I'm sure discharging multiple times has put quite a hurt on it. I'm not trying to just throw another battery at it if there is still an unresolved issue.
Thank you in advance!
UPDATE: A year and a half later. The issue stopped after a couple months. I did not change anything. I still have the same battery in the truck.