Tweet
I was advised on Mod 1 to change them all at the same time. On Mod 2 my instructor recently gave good reasons for changing them out at different times, but also mentioned he flip flops between which of the two he thinks best. Sorry if this has been done to near-death elsewhere but interested in view points.
-
GaryL -
Good question, don't know.
What does the manufacturer reccommend?Strategy without Tactics is the slowest route to Victory. Tactics without Strategy is the sound before defeat. -
a thread better suited to CCRX Clanger. just muppets here
moi y comprisComment
-
...Comment
-
I think I'd tend towards the latter option (staggered changing) mainly so that the odds of all 3 going belly-up at the same time (ie new duds or 3 at premature end-of-life) was reduced... however, since I'm still on APD's new cells, they die after a few hours so I've not ever had to change one due to old age yet!
The views expressed are my own, worth what you've paid for them, are not on behalf of anyone else and not those of any company I worked for etc.Comment
-
When I change mine I normally change them between 3-4 weeks apart with Teledynes now quite regularly with the new cells as JT mentionedComment
-
Are AP cells still failing? I had one go a few months back and they replaced all 3. So far, touch wood, they've been fine. Haven't heard of many failures recently. This could be down to them getting it right or people just accepting that there failing and get them replaced as routine without posting about it. As for the original post. I think I'll start replacing them near end of life but perhaps a month apart (assuming they reach end of life).
Comment
-
Paul Raymakers did some very interesting simulations here http://www.revo-rebreathers.com/uplo...en_sensors.pdf of the different strategies, and I think makes a convincing case for staggered swapping to minimise the risk of simultaneous cell failure. I have the n@90 cell checker and use this to determine which cell is the weakest, and to verify all cells are readin linearly and not current limited before each trip, and I err on the side of caution. It's always painful getting rid of perfectly good cells but, given the other thread re ox tox, am happy to spend money to reduce theoretical risks as far as I can.
I read recently, and I imagine it was on here or the other place, of a 3 cell rebreather where 2 cells failed simultaneously, and the two that failed were closest to each other and hence out voted the third good cell.Comment
-
Personaly I have in the past changed cells on a 6 month rotation swaping one and then two.
So 6 months in I replace cell 2 and six months later replace cells 1 & 3 then repet replacing cell 2 6 months later again.
The reasion behind this was I was keeping at least one tried and tested cell and not replacing all three with cells which could have a batch fault.
However since the great cell disaster of 2011 I have changed stratagy to replaceing one cell at a time. And yes this meens a cel will get to 18months old. And i have done this because prior to the launch of the reliable Narked @ 90 cells I was using my old BUD cells from AP and waiting wating for new cells.
In the end i discoverd two things.
1: Cells last 18months + no problem
2: When an old cell fails its no diferent to when a new APD rubbish cell fails.
As a result I have begun to question the logic of just arbitrerialy changing cells at 12 months. I have for the last two years just swaped out cells which start to run hot or have failed.
I have had more troubble putting in new cells than i have ever had with old cells failing.
ATB
MarkComment
-
Changing 02 Cells
I also use the staggered method as I have 5 cells in the rEvo, replacing them at once is not a viable option. I just changed a perfectly good one last week (it went in 07/2011! so had a good few hours out of it). As a result currently all my cells are <12months for a few more days until the oldest will celebrate its first birthday
and 3 are <6 months. My next scheduled change will be in August/September. If any of the five will fail, I'd be quite happy just to run the unit on 4 cells, but I can still put the perfectly good old one back (and probably watch it dying on the first dive!) if I wish,until I got a replacement cell from Paul.
Comment
-
Changing 02 Cells
My OP was made after reading that article elsewhere and my views about deep tox hits and maximising avoidance. To me, the staggered approach has merit so will be changing my replacement procedure to try to minimise the impact of insidious cell behaviour. Was interested in what others do.GaryLComment
-
To be honest the easiest thing to do is just buy Narked @ 90 cells and go diving
And this isnt because i hate APD. I used APD cells exclusivly right up untill Alex Dias screwed it all up for us. I did that because the old APD cells were very reliable. The new ones are a disaster and i wont dive them till they sort it all out.
Only good thing about the new APD cells is it teaching us all how to cope with cell failure and making us much more vigulent
Comment
Comment