Using rechargeable Transmitter batteries??

[Bowers]

Hi all, i have a shearwater computer with ai transmitters. Thus far i’ve been swapping out the cr2 batteries before any major trip since they don’t have a battery life indicator. But while doing some Christmas shopping i came across some rechargeable cr2 batteries. My thought is to get these and just top off the charge every week or so.
My question is; has anyone tried this? Do the batteries have enough power to ensure the computer connects when it’s a full arms length from the transmitter?
I know when my batteries get low the transmitters have trouble connecting unless i hold my computer super close to my first stage and i also know that rechargeables often have less output but im not sure by how much and if thats enough to reduce the range.
Tia!

 

[lexvil]

The normal lifespan of a cr2 is very long and not opening a battery compartment very often is a good idea, I don’t think it’s worth the risk when you can just bring a spare battery along and switch it when it needs it.

 

[Divin'Papaw]

Hi all, i have a shearwater computer with ai transmitters. Thus far i’ve been swapping out the cr2 batteries before any major trip since they don’t have a battery life indicator. But while doing some Christmas shopping i came across some rechargeable cr2 batteries. My thought is to get these and just top off the charge every week or so.
My question is; has anyone tried this? Do the batteries have enough power to ensure the computer connects when it’s a full arms length from the transmitter?
I know when my batteries get low the transmitters have trouble connecting unless i hold my computer super close to my first stage and i also know that rechargeables often have less output but im not sure by how much and if thats enough to reduce the range.
Tia!

One concern I would have is the repeated removal/replacement of the battery. None of the AI transmitters are exactly designed for this. I would be concerned with the wear and tear on the threads and o-rings of repeatedly pulling and then replacing the battery. The cost of CR2 batteries is a rounding error relative to the cost of diving as a whole. Personally, I prefer to just replace the transmitter batteries once a year or if they drain low enough to trigger a warning on my Shearwaters.

 

[Bowers]

One concern I would have is the repeated removal/replacement of the battery. None of the AI transmitters are exactly designed for this. I would be concerned with the wear and tear on the threads and o-rings of repeatedly pulling and then replacing the battery. The cost of CR2 batteries is a rounding error relative to the cost of diving as a whole. Personally, I prefer to just replace the transmitter batteries once a year or if they drain low enough to trigger a warning on my Shearwaters.

I was thinking of that, but wondered if i keep the oring lubed each time if it would handle the extra abuse?

 

[rmorgan]

The Peregrine TX has a low-battery indicator for the transmitter; I believe Perdix also does.

 

[tursiops]

The Peregrine TX has a low-battery indicator for the transmitter; I believe Perdix also does.

My old Oceanic OC1 also had a transmitter-battery level indicator. Also AauaLung, Sherwood, and of course Shearwater. Probably others.
The battery status is sent in each transmission as good, low, or critical. The battery voltages corresponding to those three levels are >2.75V, <2.75V, and <2.5V.
A fresh CR2 is nominally 3.0V. Some CR2 rechargables are 3.7V; that does not sound like a good idea.

 

[lexvil]

My old Oceanic OC1 also had a transmitter-battery level indicator. Also AauaLung, Sherwood, and of course Shearwater. Probably others.
The battery status is sent in each transmission as good, low, or critical. The battery voltages corresponding to those three levels are >2.75V, <2.75V, and <2.5V.
A fresh CR2 is nominally 3.0V. Some CR2 rechargables are 3.7V; that does not sound like a good idea.

I think the issue is that it takes so long for a low signal to come along people are not aware that there is a warning feature.

 

[tursiops]

I think the issue is that it takes so long for a low signal to come along people are not aware that there is a warning feature.

If you just auto-change your transmitter batteries annually you'll probably never see a LOW signal, much less a CRITICAL. The new CR2 costs a few dollars at most, so is hardly worth replacing with a rechargable.

 

[Bowers]

If you just auto-change your transmitter batteries annually you'll probably never see a LOW signal, much less a CRITICAL. The new CR2 costs a few dollars at most, so is hardly worth replacing with a rechargable.

This had been my thought, but ive had to change mine multiple times this year and though i don’t get a low warning i can tell they are low when i start having trouble connecting. Near end of life they require me to hold my teric close to my sidemount tanks to get the reading to come back. Perhaps it’s just my choice of batteries? Either way, that’s why ive been looking at options. I very well may just get used to changing them every couple of months to be sure. I don’t want a failure during a tec or cave dive..

 

[Bowers]

My old Oceanic OC1 also had a transmitter-battery level indicator. Also AauaLung, Sherwood, and of course Shearwater. Probably others.
The battery status is sent in each transmission as good, low, or critical. The battery voltages corresponding to those three levels are >2.75V, <2.75V, and <2.5V.
A fresh CR2 is nominally 3.0V. Some CR2 rechargables are 3.7V; that does not sound like a good idea.

I was worried that the rechargeable wouldn’t have enough juice, but 3.7 seems better to me? Im not well educated in batteries but this is going in the direction of the understanding i am after. Can you elaborate further?