Ni-mh work fine and last longer than alkalines. You can get 1200ma or high power 1800ma. Just make sure the charger goes as high as the battery rating or you won't get a full charge.
Ni-mh also won't get a memory. You can top them off in the charger anytime.
Older Ni-cad needed to be fully discharged to get a full recharge. Not sure if Li-ion
Are like that.
MegaBass head, SWR 210, Trace 115, Ibanez RB999, 27" Imac I7, Onyx 1640I, Motu Ultralite