cell failure times

Andy Del

I'm just curious, how long have people had a cell last for?

I know we are told to change them out at 12 months, and like good divers, we repeat the mantra until we are convinced these nasty cells are just waiting for the 13th month, when they are freed by the Gods to wreak havoc and destruction upon us, the slack diver.

Now don't get me wrong! I'm not suggesting we all go and use our cells for 24 months, or 36 months, but how long have people had a cell function fine, and when did they finally get the heebie jeebies and toss it for a new one?

edited part - so I voted option 4. I have always had about 12 months out of a cell - although the last buddy cell lated 10 months! I changed him over late last year, and due to time, didn't really go checking the replacement dates of the other cells. In fact, due to being a busy bugger,I only did the occasional mv check, or linearity check. They were fine.

Now, having gone on a trip, I took a spare cell and today decided to actually have a look at my cells today. All were in MV range, and all were fine in O2 from 1 ata to 2 ata, although one was rather slow in respose. It was dated Septmber 04 and was installed in Feb 05! Suffice to say, I swapped it out...

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nigelh

None of the above.

I used to check them occasionally and let them overrun 12 months and they always seemed to keep working. I changed them when I realised they'd done their time but that could be 18 months plus.

However these last few years I've never had them all last 12 months. This corresponds to my diving deeper but also slightly less frequently but I don't know if that is relevant. I tend to swap them as a set but I'm never sure what to do with the good but removed ones so I seal them in a bag with a date label and trash them when their 12 months is up. Cells are getting to be a significant fraction of my diving budget.

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nigelh

onetime

I chose that I change them out @ 12 months religiously. OK, it's not quite "religiously" but generally it's at about the 12 month mark give or take 1 or 2.

I've gotten a short life cell in each of the last 2 years where calibration became difficult. As soon as it was a chore to calibrate it got tossed. Both of these were @ about the 8 month mark. I then treated the new one as an old one (not making use of some of its life) and replaced with the other 2 as I didn't want to deal with changing out cells at different times.

bletso

It is impossible to prdict. I had one set last 100 + hours dive time over 2 years. Some only about a year.

Life of a cell seems to related to time/dose. Two or three years if you dive a little and low set points or twelve months or less if with higher set points and lots of deco (higher PO2's)

As cells are galvanic, the more elevated PO2 they see, the faster they are used up.

I just use them until they don't perform correct. I verify linearity up to 1.6 ata from time to time in a pressure pot.

Dale

divetheworld

I would have to select a number of choices to be accurate.

I change my cells at 12 months +-1 month without fail.
My cells have died after 8months.
I check them regularly with a 1.6 flush and replace when I sniff a problem.

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Gilles

I put the oldest (or dodgy-ist) cell in position 3, and the newest in position 1.

I've gone though 9 cells.

1 still working after 18 months but I changed it anyway

2 became dodgy around 18 months

4 started getting slow between 12 and 18 months

1 became current limited after 3 hours use

The last was purchased already current limited (8 months after manufacture) and was returned. Replacement still in the drawer.

Rather than test with O2 @4-6m before each dive, I'm starting to always use dil with a min 1.2 Po2 and I check the cells (via dil flush) on bottom, and again at end of dive using O2 @4m.

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Gilles
http://www.dirrebreather.com