Hi Frank, it is safe to put in higher capacity NiMH rechargeables - they won't harm your camera at all. The only thing that would harm your camera (in terms of power sources) is a battery pack with a higher voltage than the F5 accepts. What would a too high voltage be? I don't know for sure but it must be more than 12V (8 alkalines) as the F5 accepts also 8 lithiums (13,6V). I would even try to put 11 cells into the F5's battery compartment to get 13,2V (or 13,75V with 1,25V per NiMH cell which is the voltage I meassured). But I think there is not enough room for that. 9 cells fit perfectly and make up a perfect 10,8V-MN-30 functioning fine in my camera an costing only 30% of the original. I am charging it with a Conrad charge terminal available from the German Conrad company. Loaded greetings sImOn, Vienna, Austria who used Varta cells and doesn't know anything about the other brands. From: "Frank Gao" <[EMAIL PROTECTED]> Subject: [none] [v04.n143/17] Message: 17 I am thinking of modifying my MS-30 to house 10 AA batteries. Some people posted on the list about carrying 10 NiCds with their MS-30s. Did anyone ever use 10 NiMHs in his/her MS-30? I think a modified MS-30 + 10 NiMH would behave just like an MN-30. It should be safe also since Varta AccuPlus is 1100mAh which is lower than 1150mAh of an MN-30 NiMH battery unit (based on Bob Groves' measurement). Please correct me if I am wrong. Thanks Frank P.S. BTW, is anybody using NEXCELL AA NiMH(1300mAh) rechargeables? They are about half the price of Varta, but are they good?