Hand Held Light Questions

[gcbryan]

I see that several hand held light manufacturers offer recharging in the flashlight body. The plug in must allow for venting during the charging process.

1. Why don't we see this in more hand held lights?

2. Why aren't there more focusable hand held lights particularly those using two lens in addition to the flat protective front lens? Is this that much more complicated? There is still only one lens moving. On a side note, when you have a moving, focusable head does that necessarily introduce another potential place to leak (I'm not clear about this aspect)?

3. Since once you assemble a led light you don't need to get into the head again why aren't light heads permanently sealed using gaskets/glue or other technology? Unlike a HID, with a led you aren't going to be replacing the emitter.

With a sealed head, magnetic switching, and internal battery recharging many of the failure points would be eliminated or reduced it seems.

 

[Packhorse]

1. What benefit does it offer?
I dont see any. You still need a threaded hole to stick the charger into. Why not just make that hole large enough to put batteries in and out. This way you can keep 2 sets of batteries in case you are in a situation where you cant use the charger. In fact with some designs ( like the W200) there is only 1 threaded section that allows access to the switching, batteries and LED/ driver. Adding an external charging point just adds another hole and potential failure point.

2. More parts, more complicated, more expensive. Also since the head must now twist to facilitate focusing the sealing Oring is no longer static but dynamic and this can increase the chance of a leak ( probably not by all that much).

3. What happens if the driver, LED's or batteries fail? How would you replace them?

 

[gcbryan]

1. What benefit does it offer?

Well, it seems to me that any design that keeps one from having to open and close the light head is a good thing.

If the design is using a tail cap that is probably better but I would still think that a small hole (stainless screw with o-ring) might be less prone to leaking.

3. What happens if the driver, LED's or batteries fail? How would you replace them?

Make the light reliable or cheap enough so that this is a reasonable trade off. Or, in the case of batteries, have a way of opening the light to get them out once a year or so to replace them but still make it less invasive on a daily basis for recharging.

There must be some reason some manufacturers do it this way.

Just as an aside, I see that it is possible to use molded abs housings for higher powered led's. UK has a 900 lumen version of the Light Cannon in the same kind of abs housing. The emitter is reverse mounted (facing the reflector) on the lens with the heat sink protruding to the water side of the lens.

 

[Packhorse]

But you still need to seal off the charging jack while diving.
Is a small hole less prone to leaking than a large hole? I cant see why.
In fact I suggest the opposite.
I have in my possession a Intova super Nova that has an internal charging port sealed off with a plug like you suggest. The owner forgot to replace the plug before he dived and ruined it. I have heard similar stories with the Darkbuster HID.
I cant imagine anyone forgetting to replace a tail cap on a light that also holds the batteries in place.


Im simply not a fan of throwing things away. Its slowly ruining our planet. Design and build it so it can be serviced and upgraded is my philosophy.

 

[gcbryan]

I don't know the answer but if having a small hole should prove to be more reliable than an end cap I'd rather have the small hole. Whether some people can't remember to put the plug back in or not would not be an issue in my decision.

I agree it's better to be able to get into the light to fix things but it is a trade off and perhaps the concept is useful. Maybe you can seal up a light head in a reversible way something similar to locktite.

I'm just throwing out ideas as it's sometimes useful to think outside the box a bit otherwise there is no change or improvement.

 

[Fluor]

What about charging from outside with out having the cap you can forget?

There are water tight plugs that won't give a leak if you forget the cap. And what about just xposing the charge port to water? One + terminal with a diode on the inside. No current will go out when diving. Just vipe off the port and charge.

Is ventilation a problem with cahrging of a Li-Ion battery?

 

[Packhorse]

........... One + terminal with a diode on the inside. No current will go out when diving. Just vipe off the port and charge............

Problem with this is that the charger can not monitor the voltage of the battery.
I guess with some chargers this isnt a problem but I know with my charger it will not work.
The way around this is to add a reed switch inside the battery pack and a magnet in the charger. This adds to the complexity of the system.
This is something I thought about in the past but in the end I gave up on it as I just didnt see the pros out weigh the cons.

 

[whitenoise]

I'm certainly no expert, but I agree with what Packhorse has to say. Replaceable batteries are just so much better

 

[scuba steve]

follow this thread http://www.candlepowerforums.com/vb/showthread.php?t=247398 it sounds like the handheld mentioned in that is your answer. i saw it in the flesh and it is AWESOME.

 

[gcbryan]

Just for the record I'm not necessarily talking about batteries that aren't replaceable. Just trying to eliminate the opening and closing after every day of diving. If the light is well designed and does leak with opening and closing each day then I don't have a big need for it to recharge in the light either.

I'm certainly no expert, but I agree with what Packhorse has to say. Replaceable batteries are just so much better