I do not use my 2008 king Ranch much. I had to buy a battery tender for it.
When it sits idle for 2 weeks the battery goes completely dead. Is this normal ?

 

Yes, there is a lot of drain going on when these trucks are sitting. The sytems stay hot even thought the key is not on, much like your TV, computer, etc.

 

I just bought a battery tender for my F150 too. My Bronco became my DD about 8 months ago.The F150 sometimes sits 1-2 weeks at a time without getting used and the battery kept going dead.The original battery finally crapped out and wouldn't take a charge so I bought a new battery and that still goes dead after 1-2 weeks of sitting.
Thanks for reminding me, I gotta go out to the garage and hook up the battery tender.

 

Just get a battery disconnect and flip the lever while you let it sit.

 

I bought one of those solar chargers and just plop the cell on the dash when it's parked. I had it sitting for 4 months while I was deployed and it worked great.