Hey guys,

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