Oops, I read this all again and I think I understand it better. The MOSFET is activated just at the start of the 2 minutes. Then the capacitor holds the voltage at the activated level while the processor turns off for most of the remainder of the 2 minutes. Then the processor wakes up, deactivates the MOSFET, and goes back to sleep for 90 minutes. Hopefully I have that part right. My question at this point would be, how much current leaks through the MOSFET when it's off during the 90 minutes (and this would also be for the entire first month)? ThanksI was thinking that powering the MOSFET all the time would take more power overall than would activating the the latching relay. I guess that's where the capacitor idea comes in--there would be no current flow through the MOSFET between wake-ups? I need the system to be as reliable as the relay approach, but am all for saving space and simplifying. I'll look into these suggestions; thanks!