axa,
Have you had the battery load tested? Will your battery start your DF?
I was looking at buying a 1989 Toyota truck the other day. The seller had to put a battery pack on the truck to start it.
Removing the battery pack from the running truck and the truck would die. The guy put a new battery in it and all was fine. I bought the truck and been driving it with no issues. The truck would not run with the dead battery in it.