Parasitic draw?
 

During recent trips away from home, I've returned to my car at the airport parking lot and found the car completely dead. No lights, no clicking when I crank it, nothing. No lights were left on, nothing that I'm aware of to draw power. The car only sat at the airport from Thursday morning till today (Monday) morning this time. I don't have any problems during normal usage and have left it in the driveway for a full weekend without problems. Any idea of what to look for/at? Any assistance appreciated.

how old is the battery? with the recent dip in temps (especially CO), the colder weather could have sent the battery over the edge during your trip

Battery was replaced in July. I had it checked after the first incident and everything read as it should. I don't believe it to be the battery, but I can't completely rule it out either.

I heard of some of our cars not turning off the cooling fan that runs after you turn the engine off,.... that may have caused the battery to run out?

Not at all likely. If that were the case, I'd have this issue on a daily basis, or at least I'd hear the fan running when I returned to the car after parking at a store or after a day of work. That has never happened.

Going back to a possible battery issue, I had my car out overnight last night and it was down to 18. No battery issues at all. that's the coldest it's been in my area. I'm sure it was never that cold while the car was at the airport this time and it certainly wasn't below freezing when I left it at the airport back in October. I don't believe this is a battery issue, but I will have it checked again.

Any hard-wired aftermarket components (alarm, stereo, dashcam, etc.)?

FWIW: Our fellow member, Iggy, posted a most useful video, published by Eric the car guy, on 5/10/17, regarding diagnosing peristaltic draw issues. Rather than a stab in the dark approach, the electrical system needs to be tested to isolate the circuit causing the draw. Once the circuit causing excessive draw has been identified, it's components can be checked to determine which is causing the problem, and that specific component repaired or replaced. Not all that complicated.

Not a one.

Thanks! I'll look into that once I get the battery checked again. I'll get a couple of places to look at it and compare results. If the conclusion is this is not a battery issue, I'll begin testing the circuits.

So I had the battery tested, it was found to be bad and was replaced. Everything was fine until this past week when I once again left my car at the airport for a week (Mon morning through Fri evening). Upon return, all I got was the dreaded clicking - not enough battery to turn the engine over. A quick jump and I was on my way.

My drive home from the airport is only about 20 minutes or so, but I've had no problems since. The car sat from midday Saturday through Monday eve and then started with no problem. I'm beginning to think the car has separation anxiety and doesn't like to be left at the airport. :-)

Time to start doing the formal testing to see where this apparent draw may be coming from.

For a year, my 2002 TL battery goes dead if I leave it plugged in for 2 days. I didn't try hard to isolate the problem. I just ended up unplugging the battery. That turned into buying a kill switch under the hood (actually, a knob to turn on and off). One night, I noticed that the glove compartment light always stays on while it's closed. I pulled the bulb and that was that. Fast forward less than a year later, the car is having a parasitic drain again and goes dead after two nights even with a brand new battery. I don't know what the cause is this time. The car does have a failing alternator (not charging battery periodically). I'm going to replace the alternator this weekend. Maybe that might be the fault. I'll report back later.