Inspiration Cells

***Beanie*** · 23rd February 2005, 16:38

At what point do you change your cells?

I was told of a cunning plan don't carry new spare cells. just keep the old ones.

But at what point should the cells be changed voltage wise?

I know the handsets have an operating range but I'm thinking that your going to get errors down at the lower end of this?

cheers

***caveseeker7*** · 23rd February 2005, 17:39

You can just measure the cells with a voltmeter and you'll know where within their supposed range they are.

The problem is that when you calibrate, you can only calibrate to 1.0 (unless you calibrate in a pressure pod). So any setpoint above that already means you're trusting without verifying! Since cells usually fail at the high output end (i.e. give out less volatge than they should, registering below setpoint) you don't want to get the last hour of life out them.

Also consider that the Inspiration, unlike the Prism and upcoming Vision electronics, doesn't track/verify cells. So if you use cells about to sign off, and two of them do so in proximity, your controller will vote the good one out and inject O2.

Duncan Price · 23rd February 2005, 17:47

I always check that I can drive my cells above the setpoint and back it off to something less. Unless they both fail mid dive I should be OK. Normally run at a set point of 1 anyway unless the depth/diluent makes this impractical and then I'll up it a bit. Not optimum for deco I know but since I don't have a CCR computer I make it up based on programming various OC mixes into my computer and manually toggling between them so that my CC mix is always richer than what my computer thinks I'm on.

Drmike · 23rd February 2005, 18:08

Spiking O2 on descent to just above setpoint will tell you cells can work ok to control to at least your setpoint for the dive.

O2 flush at 6m at end of dive will tell you if they are starting to become current limited and to what degree. If I cant get 1.6 its time to change them.

***Beanie*** · 23rd February 2005, 18:42

cheers guys

some great thoughts there I shall ceck my cells out in the comfort of sunny vobster at the weekend

23rd February 2005, 16:38	#1 (permalink)
*Beanie* Gallery Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,292	Inspiration Cells At what point do you change your cells? I was told of a cunning plan don't carry new spare cells. just keep the old ones. But at what point should the cells be changed voltage wise? I know the handsets have an operating range but I'm thinking that your going to get errors down at the lower end of this? cheers __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
(Offline)

23rd February 2005, 17:39	#2 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,535	You can just measure the cells with a voltmeter and you'll know where within their supposed range they are. The problem is that when you calibrate, you can only calibrate to 1.0 (unless you calibrate in a pressure pod). So any setpoint above that already means you're trusting without verifying! Since cells usually fail at the high output end (i.e. give out less volatge than they should, registering below setpoint) you don't want to get the last hour of life out them. Also consider that the Inspiration, unlike the Prism and upcoming Vision electronics, doesn't track/verify cells. So if you use cells about to sign off, and two of them do so in proximity, your controller will vote the good one out and inject O2.
(Offline)

23rd February 2005, 17:47	#3 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	I always check that I can drive my cells above the setpoint and back it off to something less. Unless they both fail mid dive I should be OK. Normally run at a set point of 1 anyway unless the depth/diluent makes this impractical and then I'll up it a bit. Not optimum for deco I know but since I don't have a CCR computer I make it up based on programming various OC mixes into my computer and manually toggling between them so that my CC mix is always richer than what my computer thinks I'm on.
(Offline)

23rd February 2005, 18:08	#4 (permalink)
Drmike RBW Member Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,337	Spiking O2 on descent to just above setpoint will tell you cells can work ok to control to at least your setpoint for the dive. O2 flush at 6m at end of dive will tell you if they are starting to become current limited and to what degree. If I cant get 1.6 its time to change them.
(Offline)

23rd February 2005, 18:42	#5 (permalink)
*Beanie* Gallery Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,292	thanks cheers guys some great thoughts there I shall ceck my cells out in the comfort of sunny vobster at the weekend __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
(Offline)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode