How many cells to change

Pokeystar · September 23rd, 2012, 09:41 PM

My cells are coming towards the end of the first season and i am going to bring changing them. I see some people swap cells out one at a time. I was going to change all three. Is there any reason for not swapping all at once?
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DSix36 · September 23rd, 2012, 10:23 PM

Quote: (Originally Posted by Pokeystar)

My cells are coming towards the end of the first season and i am going to bring changing them. I see some people swap cells out one at a time. I was going to change all three. Is there any reason for not swapping all at once?
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By NOT swapping all out at once, you can still have some that have a proven history of reliability. Just because cells are new does not mean they will work properly or for very long. You will also be using cells from different batches so that if their is a problem with the manufacturing, they will not all crap out at once.

Michael Thornton · September 23rd, 2012, 10:26 PM

Quote: (Originally Posted by DSix36)

By NOT swapping all out at once, you can still have some that have a proven history of reliability. Just because cells are new does not mean they will work properly or for very long. You will also be using cells from different batches so that if their is a problem with the manufacturing, they will not all crap out at once.

Agreed. If you can do one every six months its not that much money and gives me a little more confidence in my cells. that has always been what I try to do.

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**PeterN** · September 24th, 2012, 04:59 AM

Some cells are faster than others. If you have a eccr, this can be a problem. A mccr is less of a problem as one can watch the cell catch up.

I need to swap out a cell soon, and am thinking of switching brands. I think I shall buy one at a time and live with the different cell speeds as I did this previously and had no issues on my mccr.

Peter

**Mark Chase** · September 24th, 2012, 08:02 AM

Quote: (Originally Posted by Pokeystar)

My cells are coming towards the end of the first season and i am going to bring changing them. I see some people swap cells out one at a time. I was going to change all three. Is there any reason for not swapping all at once?
Sent from my GT-I9100 using Tapatalk 2

Defo swap one at a time and monitor its performance against the other two known cells.

New cells can be current limited and can fail straight out of the box. Diving a unit with a matching batch of cells opens you up to potential batch failure issues.

Just because a cell is 12 months old doesn't mean its about to fail. I have run cells for two years that never failed and cells for less than a year which have.

My unit (JJ) doesn't get up set about cell errors so i tend to replace cells when they show signs of failing rather than at an specific time period. i do that by checking millivolt output and testing the cells on the dive.

ATB

Mark

matt · September 24th, 2012, 09:25 AM

Mr rEvo gives good advice here: http://www.revo-rebreathers.com/uplo...en_sensors.pdf

I've been changing all 3 for 10 years and then doing a check-out dive before proper use. TAI cells were rock solid, now I'm inclined to go with rotation.

Matt.

Pokeystar · September 24th, 2012, 04:47 PM

Thanks for the replies. Rotation it is.

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September 23rd, 2012, 09:41 PM	#1 (permalink)
Pokeystar New Member Join Date: Mar 2012 Location: Dublin, Ireland Posts: 42 Thanks: 1 Thanked 3 Times in 2 Posts	How many cells to change My cells are coming towards the end of the first season and i am going to bring changing them. I see some people swap cells out one at a time. I was going to change all three. Is there any reason for not swapping all at once? Sent from my GT-I9100 using Tapatalk 2
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September 23rd, 2012, 10:23 PM	#2 (permalink)
DSix36 anti-hammerhead Join Date: Apr 2012 Location: Florida Posts: 320 Thanks: 21 Thanked 60 Times in 39 Posts	Quote: (Originally Posted by Pokeystar) My cells are coming towards the end of the first season and i am going to bring changing them. I see some people swap cells out one at a time. I was going to change all three. Is there any reason for not swapping all at once? Sent from my GT-I9100 using Tapatalk 2 By NOT swapping all out at once, you can still have some that have a proven history of reliability. Just because cells are new does not mean they will work properly or for very long. You will also be using cells from different batches so that if their is a problem with the manufacturing, they will not all crap out at once.
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September 23rd, 2012, 10:26 PM	#3 (permalink)
Michael Thornton Dive Addicts Join Date: Aug 2012 Location: Utah Posts: 329 Thanks: 118 Thanked 60 Times in 36 Posts	Quote: (Originally Posted by DSix36) By NOT swapping all out at once, you can still have some that have a proven history of reliability. Just because cells are new does not mean they will work properly or for very long. You will also be using cells from different batches so that if their is a problem with the manufacturing, they will not all crap out at once. Agreed. If you can do one every six months its not that much money and gives me a little more confidence in my cells. that has always been what I try to do. Sent from my iPhone using Tapatalk __________________ --Michael Thornton CCR Cave Instructor www.DiveAddicts.com www.CCRMichael.com TEKDiveUSA.2014 - The North American two day advanced and technical diving conference. Miami, FL - May 17-18, 2014
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September 24th, 2012, 04:59 AM	#4 (permalink)
PeterN Supporting Member Join Date: Mar 2012 Location: Vancouver, BC, Canada Posts: 322 Thanks: 237 Thanked 49 Times in 22 Posts	Some cells are faster than others. If you have a eccr, this can be a problem. A mccr is less of a problem as one can watch the cell catch up. I need to swap out a cell soon, and am thinking of switching brands. I think I shall buy one at a time and live with the different cell speeds as I did this previously and had no issues on my mccr. Peter
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September 24th, 2012, 08:02 AM	#5 (permalink)
Mark Chase ATB=AlwaysTalkingBollocks Join Date: Mar 2012 Location: Kent England Posts: 484 Thanks: 62 Thanked 163 Times in 67 Posts	Quote: (Originally Posted by Pokeystar) My cells are coming towards the end of the first season and i am going to bring changing them. I see some people swap cells out one at a time. I was going to change all three. Is there any reason for not swapping all at once? Sent from my GT-I9100 using Tapatalk 2 Defo swap one at a time and monitor its performance against the other two known cells. New cells can be current limited and can fail straight out of the box. Diving a unit with a matching batch of cells opens you up to potential batch failure issues. Just because a cell is 12 months old doesn't mean its about to fail. I have run cells for two years that never failed and cells for less than a year which have. My unit (JJ) doesn't get up set about cell errors so i tend to replace cells when they show signs of failing rather than at an specific time period. i do that by checking millivolt output and testing the cells on the dive. ATB Mark
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September 24th, 2012, 09:25 AM	#6 (permalink)
matt New Member Join Date: Apr 2012 Location: London Posts: 1,541 Thanks: 168 Thanked 74 Times in 60 Posts	Mr rEvo gives good advice here: http://www.revo-rebreathers.com/uplo...en_sensors.pdf I've been changing all 3 for 10 years and then doing a check-out dive before proper use. TAI cells were rock solid, now I'm inclined to go with rotation. Matt.
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September 24th, 2012, 04:47 PM	#7 (permalink)
Pokeystar New Member Join Date: Mar 2012 Location: Dublin, Ireland Posts: 42 Thanks: 1 Thanked 3 Times in 2 Posts	Thanks for the replies. Rotation it is. Sent from my GT-I9100 using Tapatalk 2
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