Shearwater Swift Battery shows half depleted after only a few minutes of use

[tursiops]

The shading is tank pressure not battery life. It doesn’t show a transmitter battery gauge. Only yellow & red alerts when the transmitter battery life drops.

Exactly. The ONLY battery information is encoded in each transmission, it is either ok, low, or critical. No "half" and no Guage.

 

[rfwoodvt]

Well now I feel stupid...

As I understand it then that's just a tank icon , not a battery icon, and it has no meaning, correct?

 

[Divin'Papaw]

Well now I feel stupid...

As I understand it then that's just a tank icon , not a battery icon, and it has no meaning, correct?

It has meaning but not ragardihg the battery. It reflects graphically your tank pressure relative to the rated pressure you’ve setup for that transmitter.

 

[rfwoodvt]

It has meaning but not ragardihg the battery. It reflects graphically your tank pressure relative to the rated pressure you’ve setup for that transmitter.

Thanks,

Just found the page in my manual.

Am guessing that I may have set up the transmitter max pressure incorrectly, hence the rapid shading change. Have to wait until I return to Florida next weekend to verify those settings.

Thanx everyone for the help!

 

[steinbil]

And if you're wondering why the tank pressure drops so quickly to 50%, it might be related any combination of these 3 things:

1. Pressure drops with temperature
2. Pressure displayed in 5 discreet chunks
3. Possibly misconfigured rated pressure

1 - if you're diving in cold water, it's not uncommon for the tank pressure to drop by 10-20 bar or more when getting in the water

2 - I don't know how the chunks are divided, but I wouldn't be surprised if the "half tank" display starts in the range of 65-75% of the rated pressure. So if a 230bar tank is filled hot to 230bar, it might be 200bar when it cools down, and then after breathing down 30bar to 170bar you're already in that range.

3 - if you're diving a tank with lower pressure rating than what is programmed in the Perdix, it will think your tank is lower percentage-wise, than it is. The only thing that affects is this visual representation of remaining gas.

 

[Nosmosis]

Afternoon,

Did a couple of dives with my new Peregrine last weekend. Finally a screen I can Read!!!!

Noticed both dives that when I turned on the gas my Swift transmitter showed full battery charge on the Peregrine but within a few minutes the battery indicator showed 50% or less battery remaining and stayed that way throughout each dive.

The transmitter and Peregrine are brand new, straight from Canada this past January, these were the first two dives I have made with them and max depth on the dives was 20 feet.

Anyone else experience this?

Is this something I should consider for warranty repair?

Thanks for your thoughts.

I dive in cold water and when I do, I sometimes see that the battery life seems to deteriorate at a faster rate than before. I believe this does happen with Lithium batteries.

 

[steinbil]

I dive in cold water and when I do, I sometimes see that the battery life seems to deteriorate at a faster rate than before. I believe this does happen with Lithium batteries.

This is slightly OT, since it has now been clarified that the OP was talking about gas pressure and not battery, but I just wanted to give you a heads up about something I've noticed with the Lithium batteries, which I think might be exacerbated by cold temperatures.

The lithium energizer batteries I've used in my Perdix generally work very well and last a long time, but they have a sneaky habit of camouflaging their own discharge. When they start to get discharged, they have a tendency of "recovering" at rest, so that it looks like they have more charge/voltage than their true remaining capacity. This is something I've noticed with several of these batteries, and I now recognize the pattern. The voltage starts to drop during the dive to show the actual capacity, but each time the computer is turned off and resting for a while the next time you turn the computer on the voltage is higher again. Then the next dive it drops even more, and then it recovers again. Each time it drops faster and lower. After several of these cycles, it looks quite dramatic. The first time it happened to me, I had what I think was a full or almost full battery indicator (didn't check the voltage back then), and after just a few minutes of submersion in cold water my perdix showed a low battery warning. I never had a battery fail on me, but just experiencing how quickly and seemingly out of the blue the voltage dropped, it was enough to make me rethink how I deal with battery replacement.

Now I check the voltage during dives, and use that reading to decide when I replace the battery. I no longer trust the reading after the battery has been at rest.

 

[tursiops]

Now I check the voltage during dives, and use that reading to decide when I replace the battery. I no longer trust the reading after the battery has been at rest.

This is a good practice for all batteries, but especially for Li.

 

[Mobulai]

When they start to get discharged, they have a tendency of "recovering" at rest, so that it looks like they have more charge/voltage than their true remaining capacity.

Yes.. Li ions are very tricky with partial cycles (and temperature jumps just make it even more unpredictable); but it’s also part of their „memory“ capabilities

State of charge prediction models are constantly being updated to account for these erratic up/down jumps; my favorite version of this is when a phone magically gains 5-10% charge by closing up some apps

(Photo blatantly snatched from article in Nature, for the intrigued minds: A physically motivated voltage hysteresis model for lithium-ion batteries using a probability distributed equivalent circuit - Communications Engineering )

 

[Nosmosis]

This is slightly OT, since it has now been clarified that the OP was talking about gas pressure and not battery, but I just wanted to give you a heads up about something I've noticed with the Lithium batteries, which I think might be exacerbated by cold temperatures.

The lithium energizer batteries I've used in my Perdix generally work very well and last a long time, but they have a sneaky habit of camouflaging their own discharge. When they start to get discharged, they have a tendency of "recovering" at rest, so that it looks like they have more charge/voltage than their true remaining capacity. This is something I've noticed with several of these batteries, and I now recognize the pattern. The voltage starts to drop during the dive to show the actual capacity, but each time the computer is turned off and resting for a while the next time you turn the computer on the voltage is higher again. Then the next dive it drops even more, and then it recovers again. Each time it drops faster and lower. After several of these cycles, it looks quite dramatic. The first time it happened to me, I had what I think was a full or almost full battery indicator (didn't check the voltage back then), and after just a few minutes of submersion in cold water my perdix showed a low battery warning. I never had a battery fail on me, but just experiencing how quickly and seemingly out of the blue the voltage dropped, it was enough to make me rethink how I deal with battery replacement.

Now I check the voltage during dives, and use that reading to decide when I replace the battery. I no longer trust the reading after the battery has been at rest.

I started carrying a voltmeter in the save-a-dive kit!