Shearwater Teric or Perdix?

[Marie13]

Yup, that's my issue with the Perdix... it sits "below" my ring. I need to push it well up my arm. The Petral is above the cuff ring. I can't see a Teric working but apparently some are using them successfully. I'd love one for south though. I generally just dive in a vest, and my Petral does kind of wobble around on my bare arm.

I wear my Perdix about halfway up my forearm. I found that when it was closer to my rings, the button on the left would sometimes get activated by the cuff and turn on the compass. I solved that problem for good by wearing my backup Geo 2.0 closest to the ring and then Perdix next to it.

 

[stuartv]

Yup, that's my issue with the Perdix... it sits "below" my ring. I need to push it well up my arm. The Petral is above the cuff ring. I can't see a Teric working but apparently some are using them successfully. I'd love one for south though. I generally just dive in a vest, and my Petral does kind of wobble around on my bare arm.

I'm not sure what issues y'all are having. This is me with a Teric (and Kubi dry glove rings) last weekend. After a dive. Teric is still right where it was when I put it on. Admittedly, when I ordered this drysuit, I did get it with the little tabs (as you can see on my left wrist) that watch straps go through, to keep them from being able to slide around.

I don't have a picture, but my neoprene drysuit has no dry glove rings and the Teric works just the same on it.

Also, when I wear 2 computers, I wear one on each arm, so I can see my depth, etc., on one of them, even if the other arm is busy and the computer on that arm is at the wrong angle or something.

 

[Stoo]

I'm not having issues, since I don't have one. However, I have trouble accessing the buttons on my Perdix, so I'm speculating. My cuffs are higher profile than yours I see. Anyway, glad it works for you!

 

[cib]

I did recent dives with my Teric and had a Perdix as my backup. Both fantastic computers but I much prefer the Teric screen. I find it easier to read, brighter and the size of the buttons was never an issue.

 

[JamesBon92007]

The problem I see is that there is no SAFT in AAA size.

@stuartv You say that as if it's common knowledge that the SAFT batteries are the new industry standard. I somehow missed all that but I chose them for my "vintage" dive computers. This is, of course, another thread but I just wanted to hear what you have to say about them before searching for an old thread or starting a new one.

 

[stuartv]

@stuartv You say that as if it's common knowledge that the SAFT batteries are the new industry standard. I somehow missed all that but I chose them for my "vintage" dive computers. This is, of course, another thread but I just wanted to hear what you have to say about them before searching for an old thread or starting a new one.

Sorry. That isn't really what I meant.

SAFT batteries are the only battery you can use in the older Shearwater computers, like the Predator. Using a 1.5V AA alkaline was a feature added when they came out with the Petrel, I think. So, definitely not new.

Really, I was just using SAFT battery as a shorthand way of saying a battery of the right size that has 3.6V.

To make a computer that runs off 1 x AAA sized battery means you're starting off with a lot smaller battery than what is in a Perdix. If it's an alkaline, it will be 1.5V, and the overall energy available in a 1.5V battery that is that small would not run a Perdix for very long. At least, I think it would not be considered "long enough". So, to build a "smaller Perdix" that runs off 1 x AAA-sized battery, it would really (in my opinion) have to have a SAFT battery - i.e. my shorthand way of saying a battery the size of a AAA, but with 3.6V.

And even that my just be showing my butt. Maybe there is tech out there to make a AAA battery with 1.5V and still have total energy comparable what one would expect from a AAA-sized 3.7V SAFT.

So, let me back up and re-state what I meant in what I hope is a more accurate way.

An Energizer AA battery has about 4.2W-Hr of energy. A SAFT AA (LS14500) has about 8.6W-Hr. That's why a Perdix runs so much longer on a SAFT.

An Energizer AAA battery has about 1.8W-Hr of energy. As you can see, the smaller size results in less than 1/2 of the total energy available. 43%, actually.

If you build a Perdix that runs on a AAA-sized battery, as you assume 30 hours run-time on an alkaline AA, then you'd be looking at 12 hours or so on an alkaline AAA. Less if you're running max brightness and AI. I don't think that is long enough to be feasible, really.

That said, maybe if you shrank the electronics enough, it could be substantially thinner and smaller and work with 2 AAA alkaline batteries. Especially if they could source an OLED screen for it, yielding a decent reduction in power consumption at the same time.

If you had 43% of the capacity of an AA SAFT, you'd still have 3.7W-Hr, which means it could run almost as long as a Perdix with an alkaline AA.

But, since a AAA-sized SAFT - or some equivalent that contains a similar energy density - does not exist (that I know of), that is why I don't think a smaller, thinner Perdix, with a AAA-sized battery is feasible.

 

[scrane]

Stuart,
You are most likely correct in the present limitations of AAA battery technology. I don't know if the lack of a Saft AAA is a marketing consideration or a chemical one. My dream of a AAA sized Perdix is just that... a dream.
As far as Alkaline cells go, I have ruined more electronic devices through leaking goop from Alkaline cells than I care to think about. I have pretty much switched over to Ni-MH rechargables for everything outside of my Perdix.

 

[JamesBon92007]

Sorry. That isn't really what I meant.
SAFT batteries are the only battery you can use in the older Shearwater computers, .

So far I have not seen a consensus on which brand of batteries and considered the best replacement for such computers as the old Aladin Pro. I have read that some people have had their computer die during a dive when it said the battery was still at 40% before the dive. I chose SAFT based upon "this looks like it might be better than the other choices" kind of decision.

 

[Blackcrusader]

So far I have not seen a consensus on which brand of batteries and considered the best replacement for such computers as the old Aladin Pro. I have read that some people have had their computer die during a dive when it said the battery was still at 40% before the dive. I chose SAFT based upon "this looks like it might be better than the other choices" kind of decision.

I've never had my Perdix dive on a dive with battery even at 20%

 

[Ben_3]

After a lot of thinking, comparing and reviews I decided to support my local dive shop and picked up a perdix. Good thing the bill is emailed so my wife dose not stumble upon it. This thing looks sweet!!