Mountain Rescue Help

[meuge]

Hi Chaps,

I registered here to hopefully tap into your wealth of expertise. Please forgive any ignorance, as I'm purely a user of torches and have no knowledge of their electrickery.

I'm in a mountain rescue team, which means we are often out most of the night searching for people. I have a few related questions.

Firstly, I'd like to thank you for dedicating your time to this task.

1. What are the best* cells available today in Sizes AAA, AA, D? *In that I mean balance of, highest mAH, self discharge, voltage drop off.

Sanyo cells are some of the best available. The default ones most of us use, are Sanyo Eneloops, which are 2000mAh low-self-discharge cells (can hold a charge for >1 year). The 2700mAh Sanyo cells are also very good, but will self-discharge relatively quickly.

2. My current charger is a cheap uniross ultrafast charger (Charging current = AA 1000mA; AAA 400maH). Will this fully charge the 2700maH cells I currently use + any you may recommend.

There are a lot of quality chargers available at batteryjunction.com, but Sanyo chargers that come with Eneloop batteries are quite good as well.

4. The perfect torch for mountain rescue has the following criteria: Uses standard cells (AA pref for commonality with GPS), is as bright as possible, has a very long burn time, is weatherproof, and as cheap as possible. Just out of curiosity, what would you chaps recommend against my criteria so I can pass on the advice to team members looking to change their torches?

I would highly recommend the Fenix TK20, as seen here:

It can be purchased in high-visibility yellow from 4sevens.com
It'll put out 150 lumens on 2x NiMH AAs for 2 hours, or 40 lumens for 11 hours.

It's not CHEAP, but I doubt you could do much to destroy it.

 

[hurricane]

I spend a ton of time backcountry skiing and climbing in the mountains. While I understand the need to want rechargeables and power-source duplicity [e.g. AAs that work both in a GPS and in a light], I personally wouldn't and don't use handhelds. I use Petzl Myo XP Belts for the following reasons: they're lightweight, extremely bright, cheap compared to a lot of other lights, have a fantastic run-time, the battery-pack can be relocated near the body to keep it warm, run on ubiquitous AAs, batteries can be changed super-fast with pre-loaded interchangeable battery packs, they work well with helmets ... and best of all, you have your hands free, which is kind of important in the mountains. I use a handheld SureFire [U2] as a back-up and for complicated route-finding when more lumens and throw is required. While the SureFire isn't cheap, there are plenty of alternatives. In reality, the Petzl Myo XP would be just fine for everything, backed-up with a capable secondary [e.g. Petzl Tikka] light. I've used Tikkas on technical routes at night - not ideal, but they'll get you home. Petzl claims 150 lumens in 'boost mode' out of the Myo XP Belt, but it's nowhere near the quality and output of the SureFire's 100 lumens. That said, you can't negotiate technical terrain with a hand-held torch. The local Mountain SAR group where I live use Pelican handhelds and Petzl headlamps. As for rechargeables, I'd trust the recommendations of others as I know little about them.

 

[Egsise]

I've also just replaced my old head torch with an LED LENSER H7 headtorch as it seems to be the only company that makes a decent LED robust head torch. Some of the team use these and they are impressive little things

How about Fenix L1D/L2D + headband?

 

[paulr]

In the several years up to 2006 or so, there was an "arms race" of trying to make the highest possible capacity nimh cells. They went from around 1800 mah, to 2000, to 2200, then 2400, 2500, 2600, 2700. They did this by (among other things) putting thinner and thinner insulating layers in the cells, to make more space for the active chemistry. What I'm getting at is that the highest capacity cells seem to sacrifice reliability, which is why so many of us have switched to Eneloops (2000 mah, built for low self-discharge which means good insulation) even if we're not so concerned about the actual self-discharge characteristics.

Anyway, for monstrously powerful AA lights, the TK40 is about the only game in town, and it hasn't arrived yet, but has been needed for a long time. The TK20 also looks good and while much less powerful than the TK40, is still incomparably brighter than grandma's 2aa Minimag or even a classic like the 4aa Princeton Tec Tec40. I do wonder how well the TK20's low mode works with lithium cells, because of their higher voltage. This is an issue with the L2P series.

 

[Hooked on Fenix]

I know for a fact that the high capacity NiMH batteries are unreliable. A couple years ago, I had accumulated close to 100 AAs. Most of them were 2500 mAh and up. Energizer 2500s were the worst with one in four batteries failing within a few charges. On average, 1 in 4 of these 2500+ mAh batteries failed on me within the first 10 charges. Few batteries survived to be used for 50 charges. I don't think any lasted much longer than 50 charges. After throwing out many batteries already, in the last couple years I have been saving the dead ones in a bag to recycle later. The bag now has over 50 AAs and over a dozen AAAs. I have maybe two dozen high capacity batteries that still function left. They are the newest ones and probably won't last much longer. Since Eneloops became available, I have refused to buy any NiMH batteries other than good LSD cells. Not one of my Eneloops or Rayovac Hybrids has failed yet and they get used regularly. I have used Eneloops in temperatures where only lithiums would otherwise work well and they have never failed.

 

[Badbeams3]

Yet another vote for the soon to be released Fenix TK 40...probably will run at the 200~300 lumen level for quite some time...likely has a wider flood type beam...but on high (700+ lumen) should have enough brute power to light a large area at some distance. And I agree the low self discharge batt type are the way to go even though they have lower capacity. Much more dependable.

 

[jankj]

How about Fenix L1D/L2D + headband?

I would say absolutely not (but the concept is appealing).

I haven't tried this specific headband, but I have tried the niteize jackstrap version. It's OK for short duration, such as freing your hands while changing a tire or similar tasks, but it is definitely nothing for serious long-term use:

1) This mount would absolutely interfere with the hood on your jacket, a very bad idea in foul weather. At the very least, it would be a nuisance. (Do not underestimate the importance of such nuisances when you are in rough conditions - they are a real killer to the morale and take focus away from what you are supposed to be doing).


2) The sideway weight distribution creates a pressure on the side of the head which I personally find very annoying after 10-15 minutes (Niteize with LD1 is sort of halfway-OK, but is too heavy with LD2). Bearing weight on the front and back of the head is MUCH more comfortable.

 

[Barbarin]

My two cents on mountain rescue lighting.

1. An absolute MUST HAVE is a HEADLAMP. From what I have been reading i think the APEX could be great.

2. A SEARCHLIGHT. (Aka "thrower", "spotlight"...) I think Pelican makes some AA LED lights with very good throw.

Of course if they use the same kind of batts it would be better. AA's are good enough for headlamps, but unless you use a good number of them they won't be so great for HIGH POWER searchlight. I can not think now on any commercial powered with AA's, but I'm sure there are some customs.

Hope it helps.

Javier

 

[yellow]

question regarding the AA format (for both lights and GPS):
how do You plan on this?

because most lights will eat up the batts very quick and some of them wont even work with depleted ones,
also, mixing new and depleted cells might cause some danger - for the depleted cells at least

most led lights - different to halogen - run on a very constant high level and when the user notices the light getting low (but still white, thats why it is soo difficult to evaluate the state of the cells just from looking at the beam), its over with the batts.

Would they now still power the GPS?
:thinking:


... still it is a good idea to use only one format

 

[Egsise]

I would say absolutely not (but the concept is appealing).
1) This mount would absolutely interfere with the hood on your jacket, a very bad idea in foul weather. At the very least, it would be a nuisance. (Do not underestimate the importance of such nuisances when you are in rough conditions - they are a real killer to the morale and take focus away from what you are supposed to be doing).

Good point there, didnt think that hood thing at all cause i usually use the hood only when i want to warm up.

 

[drmaxx]

5. Out of nothing but curiosity, why do rechargeable cells have a lower voltage than none rechargeable? Does this mean my LENSER will put out less light on rechargeable cells?

Recharchable NiMH do not have lower voltage - in practice it actually is the other way round. For more details you can check out this helpful document:
www.eznec.com/Amateur/1.5_vs_1.2_Volt_Batteries.pdf

This is also the reason why cheaper torches do not work properly with rechargable. One one hand it is not as easy to limit the current going through the LED without (more costly) electronics and on the other hand they are capable of sucking rechargables dry - which is bad for NiMH.