DIR views on non-canister primary lights

[berndo]

Most handhelds have about a 2.5-hour burn time. If you're doing something like a C1 class, you might spend 4 hours in the water daily. Even just doing two 1-hour dives in a single day brings you pretty close to the battery's endurance, and conducting burn tests on the light becomes more important.

It's a non-issue.
A buddy of mine who's an actual 'thinking diver' uses a cordless light and changes the battery inbetween dives. lol

 

[Lorenzoid]

It's a none-issue.
A buddy of mine who's an actual 'thinking diver' uses a cordless light and changes the battery in between dives. lol

Nice option if you have the money for a second battery.

 

[berndo]

Nice option if you have the money for a second battery.

I don't know if this is supposed to be a joke but you can get several lights like the type @ChrisMBC uses with extra batteries for way less than what a proper can light costs AND have better redundancy. These days, can lights really only make sense when you do cave dives over 2 or 3 hours.

 

[lowwall]

Nice option if you have the money for a second battery.

We are talking cordless lights. Protected 21700 batteries are $15-$30. 18650s are under $10.

 

[Gelirfella]

Regarding changing batteries. Any significant failure rate from grit/water introduction when changing between dives? Or is it relatively easy to prevent this/lights are well enough sealed that this is not a real problem?

 

[JoeTPhilly]

My Flare EXP gets 2.5 hours on high and over 5 on low. It is quite all I need but I am sure cave divers need more burn time. I guess the solution is to get both. LOL

 

[lowwall]

Regarding changing batteries. Any significant failure rate from grit/water introduction when changing between dives? Or is it relatively easy to prevent this/lights are well enough sealed that this is not a real problem?

The generic lights typically have 3 o-rings behind the threads. I haven't had issues.

 

[berndo]

It is quite all I need but I am sure cave divers need more burn time.

It's enough for many, if not most cave divers. Unless you dive large tunnels with really good viz you don't even need a lot of light... running a light on low setting is fine or even better in lower viz or small tunnels.
Lights have come along way.

 

[wetb4igetinthewater]

If you want an inexpensive light that works extremely well as a DIR-compliant cordless light, the XTAR D26 1600S has an extremely tight beam, runs off 21700 rechargeable cells, and mounts easily to a Goodman handle. The whole setup (light, handle, 2 x 21700 batteries, excellent-quality charger, and bolts for attaching to the handle can be had for ~$120 USD, price fluctuations depending.

If you can find someone with a 3D printer, you can also print the top half of the handle you see below (and attach it to the Aliexpress handle I linked) to get yourself a nice thumb loop and a guard for the power button (which otherwise likes to be inadvertendly pressed).

Picture of the light beam in use last night also attached. It's an absurdly tight beam, with a brighter spot than anything I've seen except a Focus 2.0. A couple of people locally have used the D26 1600S for Fundies, and I use mine more often than my canister light for rec and T1 dives.

Any idea on how constant the output is? I don't see anything for that on wetestlights.com. I don't have any other sources for people who test lights.

 

[Lorenzoid]

We are talking cordless lights. Protected 21700 batteries are $15-$30. 18650s are under $10.

I'm admittedly not familiar with cordless lights other than small flashlight-style ones like DGX and every other dive outfit sells that use single cells like you mention. I assumed the kind of powerful cordless lights being discussed here use proprietary battery packs. But if they use generic cells, then sure, no reason not to bring some charged ones with you and swap out between dives.

edit: Yes, now that I've taken a look at the XTAR lights, those are the kind of inexpensive flashlight-style ones I suggested in a comment above the OP consider if he doesn't need the kind of insanely bright long burn-time ones that cave and tech divers use. Might not be suitable for Fundies class, but I say get what you need for your diving today and don't be concerned with what you might need for Fundies class.