Mike goes through the new KISS Go

[SavageSeaCow]

Sounds pretty naiv to me.


You still haven't answered why the deep cave exploration guys don't use revos but 3 cell units than? You think they haven't read the revo marketing brochure about 'more redundancy'? If it wasn't a gimmick but actually better, other manufacturer would have adopted the 5 cells thing by now... but nobody has.

Bill stone invented the solid state cell. He’s one of the deepest exploration guys out there. Other big name explorers used his solid state prototypes, which is essentially the same as what is in the Poseidon for decades, even after they came to commercial markets. The “why aren’t other people doing it” argument is useless. You are responsible for choosing the tech that fits your diving, not someone else. Why aren’t you diving dual megs with hydrogen dil? Richard Harris is doing it?

 

[rddvet]

Bill stone invented the solid state cell. He’s one of the deepest exploration guys out there. Other big name explorers used his solid state prototypes, which is essentially the same as what is in the Poseidon for decades, even after they came to commercial markets. The “why aren’t other people doing it” argument is useless. You are responsible for choosing the tech that fits your diving, not someone else. Why aren’t you diving dual megs with hydrogen dil? Richard Harris is doing it?

I’m staying out of this argument but I will add using “big names” to argue a point really isn’t effective. If you stay in the tech world long enough you learn that some of the “big names” are some of the worst instructors or worst sources of information, or both. I could name 3 big names in cave diving that people would automatically think are the bee’s knees. Meanwhile you listen to them for a bit and you realize they’re out of their gourd.

 

[SavageSeaCow]

I’m staying out of this argument but I will add using “big names” to argue a point really isn’t effective. If you stay in the tech world long enough you learn that some of the “big names” are some of the worst instructors or worst sources of information, or both. I could name 3 big names in cave diving that people would automatically think are the bee’s knees. Meanwhile you listen to them for a bit and you realize they’re out of their gourd.

I totally agree. It’s up to you in the end to decide what makes the most sense and follow your training and experience. Better off diving than taking your advice from scubaboard

 

[RedSix]

The process of keeping track of cells and calibrating them before every dive is a potential source of error that is eliminated with the new tech.

Not true.
As mentioned before, exposure to high temperatures, e.g. in a car does change calibration of the solid state sensors. Actually for weeks.
See here.

 

[Whitrzac]

If you're storing your rebreather in 140* + temps, you're going to have bigger issues than your cells being a little off.

 

[flymolo]

I asked this same question awhile back- what is so game changing about the solid state cells, besides the need to replace them annually?

I would imagine most people would still carrry a spare with them, like they do with galvanic cells, and you'd still want to verify the cells are working properly during your build and/or pre-dive checks, just like you do with galvanic cells.

I doubt anyone is going to just trust the sensors work before every dive because they turn on, or whatever. That seems antithetical to CCR diving.

 

[Whitrzac]

Know what happens if they do drift because of your poor choices? You recalibrate then just like galvanic cells.

I also doubt storing those at 140*+ does them any favors too

 

[Whitrzac]

Somehow a single $1500 bill seems cheaper than $300/year for 5 years too.

 

[berndo]

Somehow a single $1500 bill seems cheaper than $300/year for 5 years too.

It's not about the price.
Doesn't Poseidon offer the Seven with or without SSS as an option? Why would they do that if the SSS are way better?

If you're storing your rebreather in 140* + temps, you're going to have bigger issues than your cells being a little off.

The inside of a car gets pretty hot pretty fast. Nobody said to store it in there.

 

[Wibble]

I have no horse in this race, don't dive a CCR.

However, I think it's slightly disingenuous to say the cells "work pretty well" when the context that makes them do so is using at least three at any given moment and having an elaborate set of voting logic and processes to detect and ignore the non-working cells as part of everyday CCR diving. That the end result works isn't a testament to reliable cells, it's a result of the layers of redundancy and workarounds built on top to handle the fact that they are unreliable.

There was a well-publicised cell-related death a bunch of years back (two cells went bad on the same dive), but I think the consensus was that it was human factors (using way too old cells, ignoring alarms, etc) that really caused the accident.

I had two cells fail low on one of my first CCR dives (during training). Those two outvoted the one good cell, assuming it was wrong.

However, as I have a Revo, there's 5 cells and two independent monitors (3 cells to Petrel, 2 cells to a Nerd) thus I could clearly see that the two cells were reading low.

You are absolutely right that galvanic cells are fundamentally unreliable, hence the need for at least 3 cells.

The outlier exception is Poseidon's '7' machine. That uses two solid state cells and (AFAIUI) continually monitors the two cells over time and predicts when one is out. That machine is also quite different from all other rebreathers and is not widely seen outside of small clusters of people (who use the same dive shop).