Battery box for Oldam conversion?

[brokenhelmet]

I've recently upgraded an old oldam lamp with a customduo omni insert which works between 3.6V - 6.0V

I need to make/convert a helmet mounted battery box, ideally I'd like to use recharable AA's as they're cheap and easy to replace

Suggestions?

 

[potholer]

My personal favourites are old (as in properly old) Petzl Zoom boxes - the 2-part ones made from hard polysomethinglene with a separate top and bottom, rather than the later ones made from a flexible rubbery plastic. They're very durable, keep contents generally dry most of the time, and are easy to mount to a helmet and fit an Oldham-sized cable into.
Unless you lick out and find a mate with a suirtable old zoom who doesn't use it any more, it does involve finding an old Zoom for sale on ebay to get hold of one.

What I do with them is terminate the cable from the headset in a Tamiya connector  in side the 'end compartment', and that lets me plug in various different things - one adapter to go to a 3xAA holder, one to use 4.5V Duracell flatpacks, and also a 3xHiMH pack made from 18650-ish sized cells. The Tamiya connectors are pretty durable, and gold-plated and cheap if bought from the right place, and with appropriate greasing I seem to have few (if any) cable corrosion issues even over many years., and very many lights made.
Left open after a trip, the box dries out quickly if it does get wet, as does the AA holder.

If you found someone with a knackered Duo with a good battery holder, that could work, though it'd need some cable splicing, and often a knackered Duo is knackered because of battery holder or cable issues.
As long as the shell and lid are intact, it is possible to entirely gut a Duo battery box and remove the cable, and rebuild with a new cable and 3xAA cell holder, given a little judicious milling to allow the holder to fit inside.

With either setup, it's fairly easy to recable an Oldham in a strong and waterproof manner if the existing cable is past it, or if something thinner is desired. Sometimes, old Oldham cable may be electrically OK, but the wires end up dirty from disintegrating ancient rubber and some oxidation, and very hard to solder to.

I wouldn't swear to it, but I'm fairly sure that your insert would be better run from 3 cells than 4, especially if all your electrical connections are decent. Runtime would be essentially the same, less heat would be made, and running from 3 cells is a bit kinder to the cells as it makes it difficult for the weakest cell to get fully flattened the way that can happen when using 4 cells.
(Note that with a standard-issue Duo box and cable, electrical connections aren't necessarily perfect - both cell connections and cable connections can be impaired by corrosion.)

 

[Wayland Smith]

Maplin do quite a range of plastic boxes in various sizes, also battery holders for AA size cells.
Unfortunately nothing for 18657 LiIon cells.
I know all the problems & prices but you can at least get stuff quickly and look first.

http://www.maplin.co.uk/c/components/project-boxes?productsPerPage=24#Categorylastic%20Boxes&sort=&page=1&productsPerPage=24

 

[bograt]

I agree with Pitlamp, the old two-part Petzl zoom cases are good for the job, I picked one up in a charity shop for ?1.50.
Fitted it with 2x2 AA cell battery holders, runs a Mr Mike retro conversion a treat, suspect a 3 cell holder would fit.

 

[Simon Wilson]

...polysomethinglene...

Acrylonitrile butadiene styrene

I wouldn't swear to it, but I'm fairly sure that your insert would be better run from 3 cells than 4, especially if all your electrical connections are decent. Runtime would be essentially the same, less heat would be made, and running from 3 cells is a bit kinder to the cells as it makes it difficult for the weakest cell to get fully flattened the way that can happen when using 4 cells.

I like most of what you say but I use 4 cells and I make sure I keep them as a set of 4 so they get discharged and charged together. It's difficult to do that with 3 unless you have a special charger. Someone might tell us how to make a 3 cell charger.

 

[SamT]

1, 2, 3, 4 cell charger...

http://www.amazon.co.uk/Technoline-BL-700-Intelligent-Professional-Standard/dp/B003S4JQS2

 

[Spike]

Not that you necessarily need CustomDuo stuff pointing out to you, but...

The Rude Nora v1 Box is a brilliant (if not the cheapest) option. Fits 1, 2, or 3 cell Li-ion packs or a 3xAA adapter.

I have one attached to a converted oldham that's done me grand, with a 7.8Ah 3 cell pack that easily runs the omni for a whole weekend without thinking about it. I've just upgraded to a full Rude Nora, but I'll still be using the battery box for other lights, or I might use it as a belt/inside pocket pack...  :-\

 

[potholer]

...polysomethinglene...

Acrylonitrile butadiene styrene

That's interesting.
I'd always thought of ABS as being pretty rigid (more like Duo case material), and the old Zoom boxes are pretty flexible.

I like most of what you say but I use 4 cells and I make sure I keep them as a set of 4 so they get discharged and charged together. It's difficult to do that with 3 unless you have a special charger.

I really don't like anything but single-cell-per-channel chargers for loose cells. I use cells in all sorts of numbers, and a competent 1-cell-per-channel charger costs much less than my collection of cells. Even if I only used cells in even numbers, it's much more convenient not having to keep different sets of used cells separate from each other before charging.

Someone might tell us how to make a 3 cell charger.

I did make some for my hard-wired 3-cell packs, since before cheap hobby chargers got popular, it seemed bizarrely difficult to find a 3-cell capable smart charger available for a realistic price - there were quite a few R/C ones around which would charge 2,4,5,6,7 and 8 cell packs, but not 3.

 

[meanderthal]

What I do with them is terminate the cable from the headset in a Tamiya connector  in side the 'end compartment', and that lets me plug in various different things - one adapter to go to a 3xAA holder, one to use 4.5V Duracell flatpacks, and also a 3xHiMH pack made from 18650-ish sized cells. The Tamiya connectors are pretty durable, and gold-plated and cheap if bought from the right place, and with appropriate greasing I seem to have few (if any) cable corrosion issues even over many years.

I'm looking to do just this at the moment, but I got stuck pondering the best size to use. Ideally, I'd like to be able to swap between a nice rechargeable battery and a standard 4.5v flat pack. I found these connectors in Maplin http://www.maplin.co.uk/p/race-pack-lead-male-battery-connector-jg04e but I wasn't sure they'd fit the connectors on the batteries suggested by custom duo http://www.strikalite.co.uk/prodcat_type/20/ALL/0/Specialist_Battery_Packs.html - Does anyone know?

 

[potholer]

The Maplin connectors you linked to are the standard-sized Tamiya connectors which I use on my adapters, battery packs and chargers, but from Maplin, they're horribly overpriced.
(You linked to connectors on wires, but their bare connectors are almost as expensive.)
See http://www.componentshop.co.uk/leads-and-connectors/connectors/tamiya-connector , where they're 50p each, (?1.50 P&P for small orders) with gold-plated mating surfaces.

The battery packs you linked to use Tamiya 2s, otherwise known as Mini-Tamiya connectors
http://www.componentshop.co.uk/leads-and-connectors/connectors/mini-tamiya-connector
which are thinner while being the same length as the regular connector.
In a Zoom box, the difference in connector width doesn't make any real difference since width isn't a limiting factor.

If using those packs, as well as the helmet connection, you would likely need a connection for the charger - some chargers may come with regular Tamiya connectors, but I'm not sure many (any?) come with mini-tams. However, it'd be easy to make a regular->mini adapter to connect to a charger.

In the absence of the correct crimp tool, I tend to crimp with pliers and then solder, and I haven't had any issues with solder stiffening the wires beyond the connector (which is one of the main worries when soldering).

Getting the cable length inside the battery box right is useful for people going down the Zoom box route, I could provide more details about what I do, as I've done a lot of them.
Likewise making robust 3xAA adapters.

 

[meanderthal]

Getting the cable length inside the battery box right is useful - if you were going to go down the Zoom box route, I could give you more details about what I do, as I've done a lot of them.
Likewise making robust 3xAA adapters.

That would be useful thanks as I am simply repairing my oldham/zoom combo. I think the original problem stemmed from the cable being too short.

 

[bograt]

I agree with Pitlamp, the old two-part Petzl zoom cases are good for the job, I picked one up in a charity shop for ?1.50.
Fitted it with 2x2 AA cell battery holders, runs a Mr Mike retro conversion a treat, suspect a 3 cell holder would fit.

Sorry, just spotted my error! :-[ should refer to Potholer, not Pitlamp 

 

[potholer]

When I recable an Oldham/Zoom box setup, these days I use regular rubber mains cable (can't quite remember the diameter at the moment).

At the headset end, I solder 3.2mm bare ring terminals to the cable and cover the terminal shafts with heatshrink (which might need threading on beforehand if it won't fit over the ring terminal)
For the cable fixing, I leave the headset cable entry bare (no brass cable attaching ring), poke the cable some way into the headset and tie a standard 3.5mm cable tie around the cable outer very close to the end.
I then mix up some quick-set epoxy, and plaster some around the cable behind the cable tie, and some on the headset shell around the cable hole, then pull the cable into position and leave to set. Depending on epoxy fluidity, it might be worth leaving doing this for a minute or two until the epoxy is less likely to run everywhere.

Afterwards. more epoxy or silicone could be added on the outside, depending on what kind of gap is left between cable and surrounding headset.
Personally, for a neat finish I use a sleeved cable grommet which is undersized (and has to be stretched to fit on the cable) with the headset end trimmed to fit inside the headset hole. It's a bit of a faff to get on on the right position, and probably not really worth someone buying a pack for a one-off job, but it does look good (a 'cosmetic strain relief'), and helps stop fluid epoxy running down the cable before it sets.

To get the overall length right, I fit the box and headset to the helmet, feed the cable into the box base, pull the cable tight from the headset to the left 'leg' of the battery box, and leave a small curve of cable below the box (ie, I don't pull it ultra-tight). Eventually I'll pull the cable taut from the headset and cable-tie it to the left leg, so a little slack below the box isn't an issue, and can come in handy in case of cock-ups or moving to a different helmet.

I mark the cable just below the box with a magic marker (hard to see afterwards, but usually visible even if only by shininess) and then remove the headset from its bracket and pull some cable through into the box until I can see the mark. A cable tie a few mm above the mark is fitted and trimmed, and I can refit the headset on its bracket and pull the cable back to see if the tie is in the right position on the cable. If it is, then I can use the cable tie to get the lengths right for cutting and connector fitting.

If I'm using regular mains cable, I'd cut it so that when the cable is pulled tight with the cable tie at the box base, the whole Tamiya connector can be pulled clear of the box by 5-10mm to operate the catch easily - holding the connector in position next to the cable gives a reasonable idea of where to cut it.

After cutting, I strip the outer sheath from a few mm above where the cable tie is, then strip the ends, attach the connector contacts, silicone grease the pins and cable ends and fit the pins into the connector [the correct way round - at least for the standard Tamiyas, Red-Square is how I remember it].

If at this point I try things out and find I'd made things a little short, I could always use some of the slack I made earlier, removing the cable tie and fitting another one a little further down the cable.
Once that's done I can do the final tightening and cable-tying of the cable to the battery box leg to keep it snug and avoid snagging, and that's it.

One point is that there isn't a huge amount of spare height with either kind of Tamiya connector, so the closer to the cable tie the sheath is trimmed, the more space is available for things to fit above the end of the sheath. Leaving a cm or more of sheath could make things awkward.

I like to use releasable cable ties for the box lid - if they're looked after and not unnecessarily tightened they are pretty durable and easy to open.

When it comes to stripping outer sheaths, I tend to do it by carefully and slowly working round the cable with a small penknife blade, bending the cable to see things more clearly, and being very careful not to nick the internal wire's sheaths.

With proper Oldham cables, the spiralling wires inside are longer then the overall cable is, meaning that, for example, stripping 35mm of sheath would give about 60mm of wire.

If there's anything I haven't made clear, do ask for clarification.

 

[meanderthal]

I think that is perfectly clear (until it comes to doing it!). Thank you for taking the time to write it.

 

[Simon Wilson]

I like most of what you say but I use 4 cells and I make sure I keep them as a set of 4 so they get discharged and charged together. It's difficult to do that with 3 unless you have a special charger.

I really don't like anything but single-cell-per-channel chargers for loose cells. I use cells in all sorts of numbers, and a competent 1-cell-per-channel charger costs much less than my collection of cells. Even if I only used cells in even numbers, it's much more convenient not having to keep different sets of used cells separate from each other before charging.

I didn't know there was such a thing a single-cell-per-channel charger. So thanks to SamT for pointing it out. I have avoided anything that takes three cells because of what I perceived as a charging problem.

I used to mark sets of cells with paint. What I do now is have a few sets of different makes. It's easy to make sure they keep in sets. I friend who is an electrical engineer told me to do that.

 

[bograt]

Don't know what kind of paint you use, but nail varnish could be just as effective??

 

[SamT]

I assume potholer, that your zoom box holders are not waterproof? Or do you do something on that front.

Sent from my Hudl 2 using Tapatalk

 

[potholer]

Lack of waterproofing isn't really an issue as long as things start off with a little silicone grease on and dry out after they get wet.
I rarely run on AA NiMH, but if I did they'd be charged every trip and dry out then (and the adapters would dry out quickly.

I normally run on rechargeable 3-cell NiMH packs, and they're pretty well waterproofed. I wrap them in self-amalgamating rubber tape, which gives good protection, and before I do that  I use electrical-grade silicone to coat the cell ends just in case of leaks, and around the wires to give the rubber something to grip against. To avoid the rubber sticking to things and protect it from cuts, I finish with a layer of heatshrink.
Done carefully, with 4/3A cells the result still fits in the zoom box.

The likeliest situation for corrosion is people using big MN1203 alkaline packs, since they last for many trips, and for occasional cavers can end up leaving them in helmets for a long time.
That said, many years ago I used to use a Petzl Laser with a dim non-halogen bulb. I very rarely used the electric, and even doing a lot of caving I'd often have a battery in for the best part of a year, and didn't get much in the way of corrosion problems then as long as I remembered to put the odd drop of oil on the contacts.

The main thing I make sure of is that the cable-end connector and connectors on my rechargeable packs and other adapters get some lithium grease on the contacts and wire ends before final connector assembly.

I think I've replaced the helmet connector on maybe a couple of helmets I've done (out of quite a lot), but IIRC, they were on early ones where I used the non-gold-plated Maplin connectors.
I have seen some other people's battery packs get connector corrosion, but that was where they tended to carry battery packs in a personal kitbag which frequently got wet and got left wet. I carry spare packs in an oversuit pocket and remove after a trip, and mine stay clean.

 

[Olaf]

I used a piece of drainpipe from the diy shop for a battery box with screwed on end caps either side. I tied it to the helmet with bungee cord, and the screws for the endcaps hold the bungee cord in place extremely well. It wont work for flatpacks and it's sometimes a bit fiddly to open and close, but the pipe comes in some standard size (3.5mm I think) which fits a holder for 4AA cells just about perfectly. Very waterproof and robust and cheap as well.

However, modern LiPos have just such a better energy to weight and volume ratio that the 4AA solution is now retired. I'd consider checking the exact voltage ratings and try and use LiPos...