My 2002 GMC has a problem with the battery when it sits for a while, figured that it is the security system draining the battery. Let it go down one time and took the battery in to get it tested and they said not an issue with the battery. So I bought one of the 1.5w solar chargers and it did nothing to help. So went out and bought a trickle charge system that mounts in the engine compartment and just leave that plugged in with the TCer and it is fine now. Plus the charger will desulfate and vary the charge cycle to keep the battery in good shape. Was worth the $60.00 just to know that the truck is always ready to go.
