Using NiMH rechargeable batteries in GPS Posted April 24, 2002 quote:Originally posted by CharlieP: A typical alkaline AA cell has about a 2200 mAh capacity, so your 1800 mAh cells will have about 80% of the capacity of alkaline cells per charge, assuming they are fully charged. So if alkaline cells will power your GPS for 15 hours, then the NiMH will go about 12 hours per charge. FWIW, CharlieP In digital devices, it does not work this way. Your understanding of battery capacity would apply to flashlights - not GPSrs. Typically, you get longer life from the above battery examples with the NIMH, not the alkaline. MajBach You can't have everything,where would you put it?