I saw the minimag packaging says to not use rechargeables, I wondered if the higher current capacity would cause issues.
I've found the cost per cell of an eneloop and a lithium to be about equal and eneloop seems to have about 90-95% of the run time at least in my GPS (which has a calibration setting for each) so once you get a decent charger the cost is then pretty even.
I have two chargers, Maha c401fs and maha c9000 and bought one in 2006 and one in 2008 and they have probably already paid for themselves.