In article <4qb9hd$ire@info.curtin.edu.au>, nick@cs.curtin.edu.au says...

>On reading my Pentax FZ-400 flash mannual, I discovered that if I use
>rechargable batteries, I can set the flash to continuously discharge
>the batteries, and run them to their end. I assume this means the
>flash doesn't need the long charging between shots or something.
>How is this possible and why only rechargable batteries?

Your assumption is wrong, I think... NiCads need to be nearly depleted
before recharging to maximize the recharge. The flash apparently can do
this, but it may be unwise to allow it to do it, unless it stops the
discharging process when the voltage of the battery set is well above
zero (otherwise one of the batteries would probably be "reverse voltaged"
and damaged). To discharge NiCad AA cells before recharging, you can place
them in individual AA battery holders with a 5-10 ohm resistor in series
with a diode (band toward negative end of battery), in either order,
hooked to the two holder leads (Radio Shack has the parts) for several
hours. This will drain the battery down to about 1/2 volt. I have done
this for several years, and all of my NiCads are still going strong....
Hope This Helps