Your truck has an alternator that'll charge the battery I've never bought a battery that wasn't ready to toss in the truck and go
This is not news. I replaced my red top after 11 years, and it was still working ok. I just thought it was time for a new one, because it was cranking a bit slower. Never left me stranded though.
It's just something I do. The battery is 2 months old, but what can a quick trickle charge hurt? Not a big deal