My spouse had to get out 1996 ford explorer boosted while i was at work,so that evening i tested the battery it had a charge of 12.4 and is about 5 years old so i bought a new battery ,i put the new battery in it had a charge of only 12.36 so i went for a drive came back and tested the battery it had a charge of 13.32, i checked it again about 1 hour later the charge was at 12.7,the next morning itested the battery it was at 12.4,i unhooked the battery cables took the battery out it ,tested it again the charge was 12.58,put the battery back in and went for a drive ,came back tested the battery it was 13.4,so i started the truck and tested the battery while motor was running ,it was taking a charge o 14.3 to 14.45. so i shut the motor off . checked the battery about 2 hours later the charge read12.59 i disconected the battery cables ,disconected the alternator wires, checked the battery charge 2 hours later was at 12.62 -12.59, put the battery cables back on tested the battery it was 12.52 , chaeck the battery in 1 hour it was at 12.49.check in 2 hours it was still at 12.49 hooked the alternator wires back up chaed the battery 1 hour later tested at 12.52. to say the least i am puzzled ,went for a drive came back tested the battery it tested at 13.32 came and wrote this note. should the alternator be giving the battery that much of a charge and why is it loosing part of the charge after sitting?