cheap light upgrade for a club

[JJM]

ok, before all of you say that it has been said many times and in many ways before, I'm gonna say that I read quite a few forum topics here and in other places, and I still couldnt find a satisfactorily (?) full answer.

So, my problem is: in the club (Uni, would prefer not to say which one) we've got a lot of old battered lights, and quite a few of them simply dont work any more, or dont work very well.

I realise the easiest solution would be to just buy new light+battery sets, to mount on our existing helmets (eg. Duo fixio's with AAs - cheeper, or nova+'s) but these work out quite expensive, with duos just over 72 quid each + batterys&chargers

so I was wandering if we could maybe re-use some of the bits from the totally dead lights and build something new, or improve the nearely dying ones.

just so you know what we've got: a lot of working FX2 heads & some fixable, some FX2(red) batterys & 2 strip(rail) chargers (you know, the ones with a lot of holes)(also for FX2's i think, but might be better, as we got them of some other clubs), a lot of kirbys, most working quite well, some with short battery life and some completely dead, few lights with the tube-like batterys, working but not good. quite a few chargers for kirby-type heads, with inverters to connect to normal power sockets.

my main plan was:
A) Use the spare heads/heads off the units with totally knackered batterys together with the screw-in replacement LED bulb (just like the replacement for a duo eg. from caving supplies)[yes, i know retro2 would be ideal, but way to expensive at per-unit price], no pilot, and with some kind of custom (home) made batteries
I was leaning towards some kind of in&out AA system (kinda like in duos),as it's relatively cheep to set up, batteries and chargers are relatively cheer and easily available, and can be replaced with alkalines if somebody forgets to charge them, & it's easy to take a spare underground for the whole group.
I came up with this:
1)waterproof box (eg: ebay item:220355561229 which is a little too big OR smallest palicase/otterbox (expensive) OR one of those klip&fresh kitchen continers - cheep, small enough, watertight, but might not be sturdy enough) - hopefully stuck to the back of the helmet
2)battery holder (for 4 or 8 AA's about that later) - http://www.maplin.co.uk/module.aspx?moduleno=31427 with a pp3 connector - for now lets assume 4 cells in series, 1.2A(rechargeable) each, 2500mAh = 4.8V, 2.5Ah total
3) the spare heads with battery-side cable ends cut off, with the LED screw-in bulb (1W), which with batteries above would give: 1/4.8=0,21A > 2.5/0,21 = about 12 hours of light
4) PP3 clip, with the wires coming from the headset soldered on, with the wire going through a drilled hole in the waterproof box (rubber grommet+silicon to make watertight & cable tie on inside to prevent pulling out). The connector snapped onto the battery holder placed inside - generally free, to make taking out & change of batteries possible [unless i can get hold of flat boxes with a lid (like the klip'n fresh) which would allow all batteries to be top-loaded and the holder could secured (eg. glued) in place]

B)stick LED screw-in bulbs in the lights with poor battery life, as they've got way lower power consumption than the traditional 4/6W, and use current batteries & chargers
C) build batteries able to hold enough charge to power kirby/FX2 heads, and stick custom made connectors on the wires coming of the heads, to anable us to use the current filament/halogen setup we've got despite it's (relatively) high drainage.

and now onto the questions
Q1 - has anybody been caving with the screw-in led replacement? how does it compare to kirby/fx2/duo LED light-wise. I know there's been problems with wining/heat when these were used in duos - is that likely to happen here, and will that cause problems
[look, i'm not expecting miracles here, the lights are mainly for novices, who have never been caving with any other light, and are always looking under their feet, so a spot/diffused discussion is a bit irrelevant]
Q2 - is the general idea of the construction (A) even slightly viable (eg. would i need to replace wiring from the original heads?), or am i missing something huge, and going about it totally the wrong way?
Q3 - would the AA's short out if they got wet? (slightly damp/swimming in the sump) - how waterproof does the whole system have to be?

Q4 - all of the above so far assumes useing AA rechargeables charges in a dedicated AA charger - any way I could put them in packs (eg 4 or 8(2x4in series)) make the packs waterproof, put some connectors on, ans somehow charge the packs - that would eliminate the need for waterproof box, which would help a lot. Or would it be better to have some other kind of cells, but generally the same idea.
Q5 - any way I could use the FX2 of kirby head chargers to charge the new battery packs?

I'll make it clear once more: it has to be CHEAP. So far the system above (part A) would cost just over 20 quid per light (not including the AA charger)

Any comments, tips or help will be gladly welcome

Jo

 

[Burt]

Have PM'd you with a sneaky dodge.
Look under the "my messages" tab at the top of the screen.

 

[potholer]

On the AA battery front, I'd suggest considering Eneloops, or similar low-self-discharge cells.

They're a little lower capacity than the high-end cells but likely to be rather more durable - there are some good 2300/2500/2700mAh cells around, but there are also some pretty crap ones.
They also have the advantage that if they're charged up and left for a long time (as in 6 months+), they lose very little charge.

If it's possible to get screw-in LED bulbs designed for 3 cells rather than 4, that has definite advantages, for reasons I'll avoid boring people with at the moment.

For charging, good smart chargers (like the Maha 8-way ones) would probably be the best choice in the long run.

Especially if you have someone practical involved, there are DIY possibilities, with LED+optic+current regulator not being terribly expensive. About the only tricky bit would be how to mount everything in a headset. At least some of the commercial LED bulb conversions use old-tech LEDs, which are rather less efficient than more modern ones, so going DIY, you could well end up with something rather brighter for a given runtime.
If you were interested in that route, PM me, and I could send you a few bits + pieces to play with.

I'd suggest that you *really* should have a pilot of some sort.
From a DIY perspective, you could add 2 or 3 5mm LEDs as a pilot for very little (as in about 30p per light).

 

[Christian_Chourot]

Well, for our club I just got hold of 5 battery packs from old petzl lazers (Inglesport had some) which take 4.5v lantern cells, 5 x 4.5v LED replacement bulbs (http://www.tek-tite.com/src/product_info.php?id=2732) and 5 old FX heads rewired to some spade connectors. The result is 5 adequate, far from amazing lights, cost around ?125 in total to do. The battery packs aren't waterproof, but it hasn't seemed to matter and they go through sumps and ducks all the time. Battery life, I can't say, it's a bit subjective as they gradually dim (presumably being driverless). I can't tell how long they're adequate for caving anymore (since getting a scurion everything else seems naff!) but people haven't complained. They get a good 10-15 hours of use before I bother changing the batteries and the lantern cells are very cheap if you buy them in bulk and we easily recoup the cost with our hire charge. If I had a watertight box then I'd use rechargables instead.

If anything, at least the slight naffness encourages people to buy their own lights!

But, if I was to do it again, I'd definitely go down the route of driver, new technology LEDs and a waterproof case. It's not that difficult (except the waterproofing!)

A word of warning about klip&fresh boxes is that they're only waterproof as long as they aren't flexed or squashed, although this is obviously more apparent on a large tub. Try flexing and squashing a small one under water before you commit to using them to see how much ingress of water you'll need to tolerate.

Edit: Oh, and I just noticed your question - I just used the original wiring from the lamps and cut off the kidney packs etc. I rewired a couple of the heads so that the wires explained the polarity as well as the spade connectors but it's trivial to do as long as you can open the lamp head. The spade connectors needed a slight crimp to make them fit firmly.

I'll take some photos when I can but I'm not back in Bristol for a bit.

 

[Joel Corrigan]

Just did a speed-read of the thread as it's far too long for my brain today. If I've got the right end of your dilemma then I'd suggest talking to Dave who makes the Bisun reflector units. Cardiff Uni have just bought a load off him to modify their lamps. Ours consist of Petzl battery boxes on the back of the helmet & Ceag/Oldham headsets with LED reflectors in. These were pretty feeble but with the new ones they're as good as gold.  Long-term we'll do something about the cells (use non-rechargeable flat packs at the moment) but for now they're okay.

Not certain about duration but I did a five day trip into Riesending in the Alps a few months ago. Used three cells for the trip.  Certainly worth a look.

 

[graham]

But, if I was to do it again, I'd definitely go down the route of driver, new technology LEDs and a waterproof case. It's not that difficult (except the waterproofing!)

What makes you think you won't be doing it again?  :-\

Not certain about duration but I did a five day trip into Riesending in the Alps a few months ago. Used three cells for the trip.  Certainly worth a look.

If nothing else, that demonstrates that carbide is as good as dead.

 

[Joel Corrigan]

Carbide dead? Hmm, not convinced. I challenge anyone to stick their LED lamp down their pants and see how warm it keeps them! I still think that for big, cold Alpine stuff it'll always be an option. In the Dachstein, for example, when LEDs first came on the scene less than a decade ago almost everyone stopped using carbide almost immediately. The following year the generators were dusted off & they were back in force. Not entirely sure why (I've always sworn by them) but I suspect it's because deep alpine caving can be hard & miserable so anything to cheer you up is favoured! We call LEDs "suicide lights" and if you've spent days on end using them you'll know why! Carbide produces a great light & as long as you've got the skill to drive them then in some situations I think they'll always be popular. But I will concede that I don't use mine nearly as much as I used to......  And I am talking about the generator, by the way!

 

[jarvist]

Our club (IC) went down the screw-in LEDs for our ailing FX3s (batteries were not holding their charge). I'm not actually sure where we got them, I think the potholer above might have recommended a supplier.

They were an excellent stop-gap solution (~?10-15 per unit) till we managed to tap a uni fund for some new Duos.
We used them with the standard FX3 pilot bulbs for backup.
They provided an almost equivalent light (though cool blue white) to the halogens, but with a third of the current draw. They were much better behaved when the batteries ran flat as well, rather than dying to nothing in the ~90s of the Halogen.

However, our (I believe Petzl sanctioned) replacement bulbs for the more recent Duo main beams were extremely disappointing. The beam spread is rubbish, tight spot that just ruins your night vision put not enough fall off to light up your feet. All our freshers cave with the 14LED omni rather than bothering with the spot at all.

The FX3 + replacement LED certainly puts out more light than the Duos, and is probably a 'better' overall light except for getting the battery belt tangled in SRT harness, and the battery wedged in tight chimneys!

I'd definitely look into the aforementioned X2/X3 bisuns (as you could always go to helmet mounted NiMh AAs at a later date), I've caved off its bigger brother (the expo one) for 4.5yrs now and the genuine caving utility of the beam (the spot is perfect for looking up SRT ropes to check for rub points / observe new comers at rebelays, the super wide omni is wonderful for crawling and walking passage) and frugality of battery consumption is simply stunning.

We have a couple of the Maya 8x chargers for our suite of Eneloop batteries, and their performance has been extremely good, and well worth the investment. One-hour / ~3-hour charge choice, a reconditioning cycle and individual battery level meters. Device seems very sturdy, battery holders a very postive + heavy duty feel. Only slight issue is that ours came with US plugs (but work on 240V), so we have them dangling off 50p Tesco shaver adapters.

And BTW, if you're looking for cheap backup lights, these 7day shop 1AAA battery waterproof LED wonders are pretty impressive:

http://www.7dayshop.com/catalog/product_info.php?cPath=777_8&products_id=103420

As for Carbide, well - Meh. Has anyone new started using carbide since ~2003?
Everyone says their carbide works perfectly, everyone with carbide I've ever gone caving with ends up spending hours fettling or blow-torching through the squeezes or peeing in their generator (mmm, the smell of urine mixed with the bad egg waft of a stinky).
Lovely light (~40W light bulb?), its certainly nice going caving with someone with carbide! As long as you don't have to wait while they faff...

Heat production is definitely a unique selling point over LED, I'm going to try out one of those charcoal handwarmers in the Vercors at Easter.

I was caving in the France a few years ago with some locals (all on carbide naturally) when they dropped the tackle sac with the rock stash in a pool... massive hissing and French swearwords as everyone extinguished their carbides.
Didn't go bang, but with the heat from the reaction + the water, our food of dried apricots also in the tackle sac were delicious rehydrated by the steam + warm!

For long alpine trips we've recently found that a little MP3 player boombox makes an enormous difference, and is a lot more cheery than listening to water drops while someone else bolts (there was one available from Maplin last year for ~?17 which was a ~8cm cube with two speakers taking 4 AA batteries and an SD card - like an iPod shuffle there was no display). Just don't fill it with Leonard Cohen.

 

[jarvist]

http://www.union.ic.ac.uk/rcc/caving/photo_archive/socials/2005-03-24%20-%20FX3%20homemade%20LED/

Oh, and just dug out these photos above from a 4-Yr old hack-mount with epoxy directly into a FX2 headset (corroded reflector removed), with little current limiting resistor.
Worked pretty well considering the 5min of effort that went into it.
Ran for >24hrs off a charged FX3.

LED was mounted a little deep in the headset, so the light wasn't as broad as it could be.

Nowadays I would probably use one of the very cheap automatic current limiters available for self-build flashlights. Far superior to a resistor limit in almost every way.