>I'm working on a PIC application that is meant to be exposed
>to fairly high ambient pressures - something on the lines
>of up to 250 PSI (it's for undersea use - a deep diving decompression
>computer for diving with Helium).  This means that I can either use
>a 1 ATA pressure housing, or pot the whole works to make it pressure
>proof, and thus use a much flimsier housing by eliminating compressible
>spaces.
>
>Since this is a battery-powered device, with a total draw approaching
>30mA (due to the need for some heavily compute-intensive code, and
>thus a high clock speed), I am either going to use disposable batteries,
>or rechargeables.  I would like to use rechargeables, but most of
>the batteries I'm familiar with (lead acid, NiCad, NiMh) off-gas
>too much during charging to reliably pot, which means I'm stuck with a
bulky
>(and expensive) 1 ATA housing.
>
>Anybody know of a rechargeable technology that does not off-gas
>appreiably during charging, or something else that might work?
>
>-Will



    Most batteries will implode at those pressures.. I guess you are really
stuck with the 1 ATA housing.