On Sat, 17 Jun 2006 20:14:26 +0100, Beck wrote:

Have considered using Lithium AA batteries (non rechargable) any
these any good? They reckon the Energizer ones are up to 7x longer
power than normal AA.

They're very good, but not really cost effective, depending on the
camera that they're used in. For devices that use very little
current, you'll be lucky if they last even twice as long as regular
alkalines. In old cameras that get very short life from batteries,
such as only a dozen or two dozen shots, they might last 5 to 7
times longer. For the Fuji S5500 my guess is that they'd last at
least twice as long as regular alkalines if the flash is used a lot
(500 or more shots per set vs. 250). But if the flash isn't used,
they wouldn't provide that much improvement, maybe 1000 shots
instead of 800 or 900. FWIW, this is the expected battery life
shown in Nikon's manual for their SB600 flash, which also uses 4AA
batteries (a fixed point font will help to align the columns):

Battery type Min. recycle time Number of flashes
Alkaline-manganese 3.5 sec. 200
Lithium 4.0 sec. 400
Nickel 2.5 sec. 180
NiCd (1000 mAh) 2.9 sec. 90
Ni-MH (2000 mA) 2.5 sec. 220

Replace when charge time is:
Alkaline-manganese More than 30 seconds
Lithium More than 10 seconds
Nickel More than 10 seconds
Ni-Cd More than 10 seconds
Ni-MH More than 10 seconds

These results can't be translated directly to camera performance,
since in a camera, NiMH usually provides twice the number of shots
that alkalines do, where the SB600 is only good for slightly more
shots using NiMH batteries. But if a lot of flash shots will be
taken, you'd be better of avoiding alkalines if you don't want to
wait a long time between shots. Alkalines may start off with fast
recycle times, but they slow down very quickly in conditions where
NiMH and lithium slow down only slightly. That the lithium
batteries start off with the longest recycle time (4 seconds)
appears odd, but that's probably due to having internal circuitry
designed to prevent excessive current. Energizer mentions something
about this in their battery design manual or in some data sheets.