The 95% doesn't mean anything unless you disconnected one of the battery negatives, and checked each battery in isolation.
If it turned over a little, then you're probably not looking at a seized engine. Try this - Put the charger back on it in "start" mode. If it's a 5-speed truck, set the parking brake (or chock the wheels very securely) and MAKE SURE the transmission is in NEUTRAL (if it's a 4x4
, put the t-case in neutral, just to be doubly sure). Then get a jumper cable and connect the two "big" terminals on the starter relay (on the passenger side fender). You don't even need the key to be on for this. If that makes the engine crank, then the relay is a prime suspect. If it still doesn't, then check the main battery/starter wiring / connections - connections at the battery, battery grounds, connections at the starter.
I can't over-emphasize, doing the relay jumper thing, if it's a manual transmission truck. Be DOUBLY, TRIPLY sure that the transmission is in NEUTRAL. A guy in the next town failed to do that recently, and when he jumped his starter, it ran the engine and "drove" the truck, pinned him and killed him.