intro and suggestion on hydrogen venting

[VBra676539@aol.com]

Evening all,
	I'm a new guy to the group with a K-350 and some experience in 
commercial submersible operations (including a couple of dozen dives in one 
of Phil N's subs before he bought it).  I have a significant library on 
submersibles and operations, so if I can be of any help as a resource then 
feel free to ask--I'll try to answer.
	Was talking {emailing) Jon Shawl who had responded to some questions 
of mine, which brought to mind internal batteries.  I have some experience 
with them, too, as well as first hand knowledge of what happens when someone 
makes an error in judgement.  Jon charges his batteries with the hatch open 
and a with a fan blowing.  I would like to remind one and all that AC fans 
make sparks, too, and if they make them at the wrong time .... well, you 
know.  Bang!  I would suggest using something like bilge blowers (12 volt and 
available from any marine supply catalogue) which can be piped in from 
outside through flex hose, supplying fresh air to the charging area and 
forcing enough circulation to get the Hydrogen out the stack (conning tower). 
 Hydro caps are pricey and can be poisoned if the battery is tipped far 
enough to wet the catalyst, but are absolutely essential for operational 
safety.  Maintenance free batts ain't what they are cracked up to be, and 
vent hydrogen anyway, so plan on the H-caps as part of the expense, bite the 
bullet, and stay in one piece awhile longer.
Happy psubbing,
Vance Bradley