Inductive Charging and Bluetooth Interface?

[spectrum]

So the old dive computer is getting on in years and I'll admit that I haven't even begun do do any seat time on where to go next. Looking at how electronic gadgets have progressed I'm thinking of 2 features that seem highly desirable.

Inductive charging would eliminate the need to mess with battery hatches and make it practical to "top it off" before a trip rather than second guess that the end is near. Also with easier charging they would not need to be so stingy with power and displays could be more robust. The PDC could then be truly hermetically sealed.

A Bluetooth interface would eliminate another bridge to the outside world and save the cost and hassle of the traditional download cable. I suppose it also opens the door to keeping any eye on a buddy's status.

So, is any of this reality yet?

 

[dkiely]

The Oceanic VTX is bluetooth compatible and has a rechargeable battery in a wrist mount package. The Atomic Cobalt also has a rechargeable battery. I don't know of any computers on the market that have wireless charging capabilities though, but it'd be a nice feature on the next generation of dive computers.

 

[herman]

I would not like inductive charging. First off it's slow and it forces you to rely on non-user replacable batterie...last thing I want is an expensive dive computer that is "throw way" in a few years because it will cost more to ship it off (another good reason not to buy it) and have the batteries replaced than to buy another one.

 

[kelemvor]

There's lots of Bluetooth capable computers out there. I've got a shearwater petrel that supports bt.

AFAIK none come native with wireless charging capabilities. However...

Some computers, my Shearwater petrel for example, use standard size batteries (AA). You can get a proxi inductive charging kit and make it into an inductively charged dive computer. It still won't be hermetically sealed, but you could avoid opening the computer for years this way. Converting to inductive charging worked GREAT for my kids' video game controllers.

Personally, I prefer AA disposable batteries in my dive computer. They're easily available and in my experience more reliable. Perhaps the latter because I'm not diligent enough with the charger? Dive computers with standard sized batteries are the best of both worlds, you could use rechargeable or disposable at your discretion.

Opening the battery compartment on most computers isn't a major event such that I would even worry about it other than being careful to keep dirt out of the sealing o-ring.

 

[tbone1004]

so the sealing process is interesting because you still have to interface with the devise so there is always something to go wrong. You also have to be able to repair it unless it is cheap enough to be disposable. I.e. the new Deep6 computer at $140 I would deem as a disposable option.

The Seabear H3 has an open USB charging port and uses either bluetooth or NFC to upload information. That is about as close as you can get to what you want. Inductive charging wouldn't gain you anything over this configuration. The battery is replaceable by the service centers for not all that much money. Can't remember what it is off hand, but you can call Sub-Gravity and ask them.

The Petrel as mentioned above uses bluetooth and AA batteries. It uses a standard DIN regulator o-ring for the battery compartment, and this design basically ensures that you will always have spares if you need it. They get ~30 hours of dive time on a standard battery which is good for most people for a week of diving. Less if you're doing a lot of fiddling on the surface with it or uploading multiple times a day, but 30 hours is a long time. When we are cave diving we average ~10 hours of bottom time over a weekend so changing the battery before the trip is all we worry about. The o-ring seal is very reliable and I haven't actually heard of one every leaking from this design.

 

[RonR]

I think you will see bluetooth become standard on at least higher end computers for communications with desktops. There are two versions, and probably most will use the LE type, as it’s an easier path and data transfer for dive log info is not that much. Real USB will allow for faster transfers and be more reliable for firmware updates, but bt will allow for talking to mobile devices, which is a big reason for adding it. Bluetooth, like other high frequency RF, will not work underwater, so buddy communication is out. They only thing that works well there reliably is acoustic, such as Liquivision uses.


Inductive charging is something we have looked at and for now rejected, as it is slow, requires additional hardware, and doesn’t offer any real advantage over charging through a standard USB cable, which also doubles for data transfer. I expect to see more computers using rechargeable batteries in the future- they are very reliable and there is no opening the computer needed. The trick is managing power such that intervals between recharging can be fairly lengthy. Some have had only 10 hours or so of battery life, at which point I think I’d prefer a standard disposable (those still have better power density). On the Atomic Cobalt we get 35-60 hours of dive time on a charge, mostly depending on screen brightness. The battery is in practice user changeable (it’s in a separate sealed compartment), though it’s unlikely to ever be necessary.


Higher resolution color displays do require more power, but there is a wide variation between color computers in battery life. Conserving power requires a lot of attention to detail in design of both electronics and firmware, particularly as you add more features. It's something to pay attention to and says a lot about the design.

Ron

 

[DiveNav]

I would not like inductive charging. ....... it forces you to rely on non-user replacable batterie.......

that's not correct. You can actually design an inductive charging system that charges user replaceable batteries.

---------- Post added December 7th, 2015 at 02:49 PM ----------

I think you will see bluetooth become standard on at least higher end computers ...... probably most will use the LE ....

I agree. I have been saying this for years now.
We were the first company - worldwide - to release a product for the scuba industry based on BLE (our bluebuddy data logger) .... even before Google/Android even had working API for it. What a nightmare it was!

.....Inductive charging is something we have looked at .....

I have been looking at that too and I am not yet convinced .... in addition to the extra cost there is also a size factor to it as the RX pads are quite large for my tastes.

.... Conserving power requires a lot of attention to detail in design of both electronics and firmware, particularly as you add more features. It's something to pay attention to and says a lot about the design. ....

Amen to that!

Alberto (aka eDiver)

 

[tbone1004]

Alberto, yes and no to the user replaceable batteries. I guess it is determined by how the product is designed and your definition of user replaceable. On something like the Seabear or the Nitek, sure the battery could be replaced by the user if you were really inclined, but it isn't designed for replacement, it is designed to stay in there and be recharged, same with your new Cootwo. You shouldn't have to open that case for anything battery related, just to change the sensor. On something like the petrel, you could put inductive charging into it, but since it is designed to easily open the case, and already has quite good battery life, does it really offer you anything meaningful to go thru the expense to design it. I guess the definition has to be separated between the user can't open the case without special tools, or it uses a proprietary battery etc etc., and the user shouldn't have to open the case because it is not designed to be opened.

 

[spectrum]

This helpful!

We have had bad luck changing batteries in out Aries Atmos 2 computers. Between seating the plug and getting the lock ring just right it's not a system I'd buy again. That being said I know there are more goof proof battery hatches out there and that may be all I really need. Being able to charge via USB is one I had not considered and this would reduce battery changes to end of life, not end of charge, another attractive feature. Inductive charging seemed pretty attractive. For $125 I got 2 Soni-care toothbrushes with individual chargers. Of course I realize that at the OEM level features need to happen for very small money to hold the retail price point.

 

[RonR]

As others have mentioned, inductive charging would require additional hardware, both inside and outside the computer. A toothbrush is a perfect use case for inductive charging- limited use per day, very predictable, and it can sit in the charger most of the time- so a very slow rate of charge from a small charging station has no downside. Compare that to a dive computer on a week long live aboard dive trip.


Features like Color screens and AI demand higher capacity batteries. With the Cobalt, we wanted a diver to reasonably expect to do a week long trip without needing to charge the battery- but we know if they do need to charge, it’s going to be better if it can happen quickly. USB chargers that are now ubiquitous can typically charge at 1000 mA or more- even if the USB standard is 500 mA. We do need to have a small adapter, because the USB contacts need to be waterproof, but everything else is generic- the USB charging/ data cable and the charger- and any USB charger will work. The ability to double up and use the same charger for your phone/ iPad, dive computer, etc. and the same cable for most of them seems like a bonus. It’s not so much a cost thing- though inductive changing would add cost- as it is we just didn’t think in practical terms users would be happy with the reality, it was hard to see at this point any benefits over USB.

Ron