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silent running · 22nd June 2007, 05:40

Quote: (Originally Posted by Drmike)

You could ask my buddy Fred what he thinks - only, to put it bluntly, you cant cos hes dead
(O2 tox brought on through all same current limited cells)

-There is no benefit in changing all 3 cells at once
-There is a potential risk in changing all cells at once (batch issues or current limiting issues that could and HAS lead to death)

Of course if you dont check and change cells regularly your gonna die what ever you do.

But personally this 12 month life thinging is irrelevant to me. I check my cells before and after every dive. I stagger the replacements and I only replace those cells that begin to show current limiting to unacceptable levels (say 1.5). Blindly changing all cells every 12 months and assuming that they will be fine is not as safe as my method.

Cells can and DO fail earlier (or later)

Wow Mike, is this the first time anybody has ventured the opinion that Fred Evan's death was most likely due to multiple current limited cells? I don't doubt it and suspected as much when the details of the accident were reported, but I had no personal knowledge of the situation.

It's very clear to me that dating cells is only one part of validating them. I've gotten bad ones out of the box and also been amazed by how long they can last. I always have at least 2 new spares and all of them get checked for MV output a week before the plane leaves. Then it's the 1.6 6M test on site. I guess the only thing I haven't seen yet is a good cell within it's 12 month span failing suddenly, say from 1 dive to another. Anybody have an opinion on how often this might occur?

22nd June 2007, 05:40	#8 (permalink)
silent running Mature mouth breather Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Jun 2005 Location: U.S.A. Brooklyn, New York Posts: 1,879	Re: Cell replacement policy. Quote: (Originally Posted by Drmike) You could ask my buddy Fred what he thinks - only, to put it bluntly, you cant cos hes dead (O2 tox brought on through all same current limited cells) -There is no benefit in changing all 3 cells at once -There is a potential risk in changing all cells at once (batch issues or current limiting issues that could and HAS lead to death) Of course if you dont check and change cells regularly your gonna die what ever you do. But personally this 12 month life thinging is irrelevant to me. I check my cells before and after every dive. I stagger the replacements and I only replace those cells that begin to show current limiting to unacceptable levels (say 1.5). Blindly changing all cells every 12 months and assuming that they will be fine is not as safe as my method. Cells can and DO fail earlier (or later) Wow Mike, is this the first time anybody has ventured the opinion that Fred Evan's death was most likely due to multiple current limited cells? I don't doubt it and suspected as much when the details of the accident were reported, but I had no personal knowledge of the situation. It's very clear to me that dating cells is only one part of validating them. I've gotten bad ones out of the box and also been amazed by how long they can last. I always have at least 2 new spares and all of them get checked for MV output a week before the plane leaves. Then it's the 1.6 6M test on site. I guess the only thing I haven't seen yet is a good cell within it's 12 month span failing suddenly, say from 1 dive to another. Anybody have an opinion on how often this might occur? Last edited by silent running : 22nd June 2007 at 05:42.
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