|external battery pack
for my digicam, collected parts. actually it will take 7 batteries (8.4V). this is a dirt-cheap setup, and geared towards using what i already have, rather than going for the MOST POWER option.
if i went for optimizing power, i'd use a honking lead-acid battery. but i have oodles of NIMH batteries in size AA, because all my portable electronics run on those. the camera's internal battery outputs a meager 650 Ah, and it doesn't last very long even if i use energy saving methods (turn the LCD screen off, don't use the flash). which is no big problem when i am near a socket to plug in the fast charger, but that won't be possible much during the bus ride, nor when exploring montréal. a second battery like this costs at least C$50, which would give me nothing more than another puny battery. with the AA batteries i have, i can boost the output from 1200 up to 2300 Ah (depending on which set i use), which should last me a good deal longer. and i have more than one set of batteries, so that extends it even more.
cost of parts: battery holder @ 2.99, coax plug @ 1.75, 9V snap connector @ 1.00 for a total of C$4.75. am cannibalizing an old phone cord for the wire. can't beat that.
a little soldering, and tomorrow a usage test, and i'm hopefully be all set. i would have bought a project box because i don't want the pack to float around loose in my bag, but the paramour suggested that a simple drawstring bag would do -- indeed it would.