Modifying H600/502 for extended cold-weather use

[maitre]

My primary headlamps are the H600 and H502. While they work great in positive temps, their output/runtimes are noticeably affected by extended cold conditions. I do a lot of winter camping, ice climbing, and alpine climbing when nights are long and temps drop down to -30C or colder. The lights are fine when I take them out of my jacket to use but the cold gets to them quickly and their output/runtimes drops.

An external battery seems like the perfect solution to this problem. I would keep the batteries warm by having them close to my body while the lamp itself could stay on my head/helmet. With an external battery, the body of the flashlight could be cut down as well to save on space/weight. Heat dissipation wouldn't be an issue because of how cold the external temps would be.

Has anyone modified their H600/H502 to take an external battery pack and can point me in the right direction? I am totally okay with using this as a dedicated winter lamp.

Alternatively, are there any external-battery-headlamps that provide similar output/runtimes as the H600/502? I know Petzl has one but the runtimes/output is nowhere close to my zebralights.

 

[Woods Walker]

I also do allot of winter hiking, sometimes at night, sometimes subzero. For AA headlamps I use Lithium Primaries which are good down to -40F. The other solution is to use a headlamp which takes a battery pack on the back of the head like the Fenix HP12 (amazing headlamp) or PT Apex. Keep the battery pack under your hat and LED out. This way the battery is warm and LED cold. An almost ideal situation.

 

[lampeDépêche]

The L91/ lithium primary is a good solution for the H52.
For the H600, a similar (though less satisfactory) solution would be using a single DL123 with a spacer, or a pair in parallel.

Less satisfactory because you will not be able to access the highest output mode (though it will drive H2 and below), and because it has less power in it, so you'll have to change it more often.

But it requires no modding, it works at very low temps, and the 123s are easy to carry.

I wanted to have the option of running my H600 mkII on 123s, so I made up a little collapsible spacer with an aluminum T-nut and a couple of rubber washers. So it has a thick slug of aluminum down the center as the conductor, and fat rubber disks to hold it in the right position in the battery tube. Works fine. That and some 123s in my bag means that I always have backup options for my H600, even if my 18650s are out of juice.

I also worked up a little battery-carrier made from electrical tape and aluminum foil that allows me to run 2 123s in parallel in the H600. (You just need to route heavy strips of doubled foil from the neg of one battery to the neg of the other, and from the pos of one to the pos of the other. Carefully insulate everything with black electrical tape. The battery tube is sized for 18mm diameter, so there is plenty of room for conducting strips and tape). I made it so that I can slide batteries in and out without undoing the tape. To be honest, I never liked the design I came up with--looked too ugly and primitive.

But you could pre-tape a number of pairs of DL123s in advance for a trip, and then you would get twice the battery life (of a single cell, not of an 18650). And they would be easy to swap in and out. Just remember that they have to go in parallel, not series!

 

[maitre]

Thanks for the response guys! I thought the H600/H602 couldn't use CR123s? I've been sticking to the 18650's so far because that's what ZL recommends.

 

[psychbeat]

^^^
They are suggesting using a single 123 or two parallel which is 3volts.


Do u guys think 6v would fry the driver?
I haven't tried two 123s in my 600w but seems like it would sag a bit on the higher levels & be closer to only a volt over ...
Probably not recommended I know.

 

[markr6]

-30°C oo:

I use my H600 no problem down to about -15C, but not for any longer than maybe 1hr at a time when backpacking at night.

As much as I like Zebralights, it seems like it would just be better to go with another model since it sounds like you're using them for long periods in the cold.

 

[lampeDépêche]

I sure as heck am *not* going to try running my beloved H600 on 6volts. Would it fry the driver, or the emitter? Not sure, don't want to find out. (And psychbeat, you would only get voltage-sag with major current-draw, i.e. on the high-lumen modes. On low modes, not enough drain for sag, so full 6-volt whammy).

That's why I kept emphasizing: PARALLEL. That way, even the two batteries together only output 3 volts (although more amps). Pos to pos and neg to neg, with plenty of tape to make sure that the positive terminal of the one in back is not touching the negative terminal of the one in front, or any part of the negative pathway. It works! And it does not endanger the driver at all.

 

[MartinDWhite]

A screw on end that maintained the watertight seal and had a pair wires to some connector would be a neat project. What external battery pack would you like to use? Are you going to make your own battery pack? Do you want the external battery pack watertight? Do you even want a connector? How about just permanently connect the wires to the light and battery pack. This sounds like a neat little project.

 

[Yamabushi]

Alternatively, are there any external-battery-headlamps that provide similar output/runtimes as the H600/502?

Take a look at the Fenix HP30. It uses two 18650s in a battery pack worn on the belt or carried in a pocket.

 

[MartinDWhite]

FYI. I make and sell the required spacer to use a single CR123A in an H600. I have a H600, and a H602W, and both will run off a CR123A with a spacer.

 

[maitre]

Sorry I totally didn't pick up on wiring up the batteries in parallel haha Do CR/DL123's perform that much better than a lithium 18650 in the cold?

 

[eh4]

1, Make a CR 123 sized screw top pill which holds screw lube and extra O rings, etc. while acting as a dummy CR123 for an 18650 tube.
2, Make a dummy battery with spare screw cap lead to cable glans for a ZL H600 or other single 18650 headlamp, cable leads to a 2-4+ parallel battery pack on the back of a head strap or helmet, or pocket.

http://www.candlepowerforums.com/vb...guy-Two-thoughts-here-for-talented-machinists

 

[GeoBruin]

I have an H600 and I'm willing to do this to my headlamp for the sake of science. I'll report back once I make some progress.

 

[eh4]

Great.
If you can get a spare battery cap before drilling for power cord you can have your light and mod it too.