Min. # dives/charge or battery acceptable for dive computer?

[drrich2]

Hi:

One of the popular, full-featured AI wrist unit dive computers has been out awhile, and I was interested in it, but read about poor battery life, and the tray for the rechargeable battery looking fragile although some think it seems to hold up well in real world use. The somebody posted about using the rechargeable battery & after 3 dives the indicator goes into yellow, and someone else said he got 5 - 6 dives on rechargeable over a weekend (he didn't explicitly state how much power was left at the end of that, but the phrasing did not sound good).

Apparently computers like the Cobalt (I have) and Petrel (I've read of, not owned) have demonstrated the value of excellent screens and intuitive interfaces that operate more like an iPhone and less like programming a digital watch. Therefore, big, emmitive screens (produce light) have gotten popular, people like wrist units (compact, with small batteries) and many people like A.I. (so the transmitter needs a battery, & the computer uses more power to stay in touch with it).

But if you have to open a battery compartment every time you change a battery, I'd think there'd be a risk of flooding. Even if it never floods, the tedious hassle of frequent battery changes would be aggravating, and the fear of flooding an ongoing anxiety. I prefer the Cobalt console approach; built-in rechargeable you can recharge without opening anything, with power for lots of dives.

My question is about wrist dive computers in general, whether AI or not.

If you found a dive computer that was otherwise an excellent fit for your needs and wants, at a decent price, what is the minimum # of dives you would demand on a single battery charge before you'd pass on it and get something else?

1.) 5+ Dives.

2.) 10+ Dives.

3.) 15+ Dives.

4.) 20+ Dives.

5.) 30+ Dives.

I'm keeping it simple, figuring that even on a live-aboard in an exotic location, for a 1 week trip you don't likely get over 30 something dives.

Richard.

 

[KeithG]

i voted 30+, but then i am a dinosaur and so are my dive computers. they get around 400 dives "per charge". then a very messy battery swap is required.

 

[ajduplessis]

at least 30

 

[BrewsKampbell]

I voted 30+. My Aeries XR-1 wrist computer lasted me for just over 100 dives, now I dive a Petrel with the Saft battery.

 

[DeepSeaExplorer]

I wouldn't buy a computer that had to have the battery changed in less than 30 dives - that's crazy.

Obviously, if going that route the batteries would need to be common sizes like AA and user replaceable.

 

[Doc]

Well, you did stipulate "minimum", and I had to assume rechargeable through the case (no removal), but no total BT was specified.

I can, with those parameters, vote for 6 dives of 1.25 BTs.

You gotta sleep sometime.

This will resolve itself in due time. It is the same perplexing equation that confronts electric car design and marketing. With the coming new technologies in battery life and storage, your query will still be relevant, the algebra will remain the same, but the raw numbers of the math will be drastically altered.

No different than cell phone power-pack evolution, insulin pump batteries, cardiac pacemakers, electric toothbrushes, drills, etc. What will you bother to transport to facilitate your tool's operation?

Batteries: Size (displaced volume) + Weight (factored against displacement, but relevance u/w?) + Duration (between charges) / Cost = _____________ (realized utility)

The formula will remain constant, the numbers you plug in will begin varying and evolving by tomorrow. Battery technology is about to shift into hyper-drive.

 

[Diving Dubai]

Hi:

One of the popular, full-featured AI wrist unit dive computers has been out awhile, and I was interested in it, but read about poor battery life, and the tray for the rechargeable battery looking fragile although some think it seems to hold up well in real world use. The somebody posted about using the rechargeable battery & after 3 dives the indicator goes into yellow, and someone else said he got 5 - 6 dives on rechargeable over a weekend (he didn't explicitly state how much power was left at the end of that, but the phrasing did not sound good).


Richard.

I'm waiting for my new Suunto Eon to ship, hence I put 20 as the Eon as approx 24hrs of dive time before needing a 4 hr charge (by usb)

I'm guessing your notes about a computer above are about the same one I was looking at. I really wanted to like that model but 2 x owners told me not to bother because of the battery case and life - where I live there are no dealers and back shipping to the Country of origin would have been a pita

 

[Storker]

My AI Suunto Cobra goes at least one year on a battery (I'm getting some 30-ish dives/year these days), same as my backup Stinger. So I voted 30+.

If I could charge my PDC via cable like I do with my SOLA light and without having to open a battery compartment, I could accept less. That'd be a slight hassle, though, because I'd need to bring another charging thingie and remember to charge another piece of gear after a day's diving. Camera, strobes and light is enough if I didn't have to charge my PDC as well. And since batteries lose capacity as they get older, I think 10+ dives should be a minimum for a spanking brand new rechargeable PDC.

 

[gopbroek]

If the battery hatch has to be opened then I would not feel good about a computer that requires opening up more that once a year or 200 dives. The very act of opening and closing the compartment greatly increases the risk of leakage.

 

[RJP]

At least 100 dives or one year... which ever comes LAST!

Anything less is silly for a computer that needs to be opened to change the battery.

My Vyetc DS with transmitter gets at least this, at a 75-100 dives per year. I usually change the batteries annually during my reg servicing, and more often than not it still has about 1/4 battery life still indicated. Last week, for the first time, I had the battery on my Vytec crap out on me. I hadn't changed it in a year and half.

---------- Post added November 6th, 2014 at 09:16 AM ----------

I'm keeping it simple, figuring that even on a live-aboard in an exotic location, for a 1 week trip you don't likely get over 30 something dives.

Richard.

Assuming you want to get in all five dives a day for five and half days of diving that's 27 dives. Even with brand new batteries installed right before you leave, a 30-dive battery life doesn't give you a reasonable margin of error. And what happens if you computer ends up staying wet - and therefore staying ON - for a few hours between dives or overnight? (Everything stays WET on a liveaboard.) Either way, you're looking at a very high likelihood of needing to change the battery before the trip is over.

On a ScubaBoard thread a 30-dive battery life sounds fine. In the real world, it's woefully insufficient.

And you better hope you're not on a 10-day liveaboard trip! (When I was in Truk I did 57 dives in 18 days; 14 from the Odyssey and 4 from Blue Lagoon. I can assure you there's a far better chance of your liveaboard passing a Radio Shack in the middle of the ocean than there is of finding a CR-2450 battery on Chuuk.)