Lately when I go to Start up, it sometimes will not (crank?). turn the key and nothing just a "Click"... try again and it usually starts up. today it was cold this morning and it happened, it started after three tries. after work i went to start it up and it took 3 tries again to start.
So I'm running an Interstate Battery that was the battery My Disco has since i bought it.
I get a lot of corosion at the terminals, and i need to replace a clamp on the lead due to the nut being stripped by the guy that did my head gaskets.

 

Clean the corrosion before you buy a new battery.

 

spike, i have cleaned it before and it came back twice as bad. does this sound like a connection problem? I will clean it up, no prob... does baking soda and water really clean terminals? i did this before and like i said, now that crap is back even worse.

 

Replace the bad terminal, and while you are at the store buying a new one buy a spray can of battery terminal cleaner.
It's like $3, spray it on, it foams, let it sit, rinse with clean water.
That stuff works great.