Ok, details.
So I get into the garage at 7 when they open on Saturday.
Mechanic comes out and tries to jump it under the hood. Same result as me - clicking, followed by the crazy flashing dash lights. Then he checks back under the hood, and as he is removing the negative cable, notices a huge change in the brightness of the headlights. He tries reconnecting, and they dim. So he maneuvers the cable a bit, finds the brightest location and holds it there, then asks me to try and start it. Success! I just wasn't getting a strong enough connection. You would think that if they are designating a specific area for jump starting they would make it substantial enough to actually hold a jumper cable clamp solidly.
Anyway, after that he wanted to test the battery to make sure there wasn't a dead cell or anything.
He drove it around to an open bay, popped the hatch, we opened the spare tire area, and he tested the battery. It seemed fine, with and without a load. So he got ready to charge it, and that's when we noticed, as everything was moved out of the way, that it was a NAPA battery. So it wasn't the stock battery, and for a new replacement (non-Delco) to die would be odd....
The service manager came out to look at it, asked if the mechanic had removed the tie downs. I said, "No, he just tested it". It wasn't tied down, it was just wedged in there. They removed it. Not only was it not the correct battery, it was neither vented nor sealed. It was a class 35 regular battery for a small import car (under the hood model).
Yeah.
So they checked the Delco they had in stock for the new Tahoe, but it was a little too large, and one of the tie downs wouldn't fit. While they were waiting for the correct battery to be delivered from a local parts store, I noticed that the NAPA battery was manufactured in Nov 2007. The car was purchased new in Jan 08. So we started formulating scenarios:
1. Wife wakes up to dead battery and need sot get to work. Huspand tosses in the closest thing he has to a battery that kinda/sorta fits, it starts, and he forgets all about it.
2. Wife and husband are getting a divorce (true). He would rather collect on the insurance, so he places a potentially volatile battery in her trunk and hopes for the worst.
3. Car is repo-ed after divorce (true). Repo men see $125 battery in trunk. Decide to swap it out for a $30 battery they have sitting around and make a profit.

Anyway, new battery arrives. Fits perfectly. Vents perfectly. (Thankfully the vent tube was still in the hatch. Whoever changed out the battery didn't just toss it over their shoulder.)
Starts right up. Both keys work. Power steering works. Tire sensors work. Radio stations still saved. Clock needed to be re-set.
Only problem I can see is that my oil life was at 75%. Now it's back at 100%. So should I just get an oil change at 25% to be safe?
Paid $123 for a 72 month battery and drove away to begin to make up my wife's birthday to her.

So, stupidity caused a ruined birthday, but may have inadvertently saved our lives by discovering an unsafe battery venting into the cabin. At least I didn't try to charge or jump it from the battery on Friday night.

Thanks for all the help.

Joe

 

Glad you got it sorted, and now have a proper safe battery.

 

Girlfriend's 2006 hhr wouldn't jumpstart using the under the hood terminals, had to jump the battery directly. Seemed to work :)

 

If it would jump start at the battery itself, but you couldn't jump it at the under hood location, you either didn't have a good connection with the cables or an incorrect connection.

 

I sometimes have trouble getting a good - connection. I got a piece of metal strapping and mounted it under the marked strut mount nut. Now I don't have to be a contortionist to connect the jumpers.