Why does an Optima battery take a different charger

where I work we removed the gel battery's because they keep destroying the dual alt. on our ford ambulances ,they the (battery's) require a stand by charger twice the regular amp output for standby also they make the alts put out almost twice as much as regulator battery's when charging also (as said) need a higher voltage setting about 14.6 /14.8 a reg.battery might pull 60 amps after start up and the gels are pulling 100amps to recharge which shortens alt life ,we saw no reason to run them they just didn't prove out , not everything new is better just a different sales person/engineer getting his %