DIy 700 lumen batteries inside light

Just completed a 1/2 power on the bench test on my two lights, both lights switched on with one common 8 cell Eneloop pack. Lights are built up with front fully sealed, backs screwed on but no silicone seal yet.

Some details:

Room temp 19C
No forced air flow
Start voltage of pack (off load) 11.1V
Resistors for 1/2 power chosen at 180Kohm approx 470MA through LEDs for each light.
Measured initial current draw from Battery pack (total for both lights) 620mA = 2 X 310mA.
Initial voltage on load dropped to 10.4V after 1 min and stayed steady for several minutes.

Case temp reached steady temp of 40C after 6mins and stayed there for the remainder of test – both lights pretty much identical.

Back panel always felt cooler than the case.

Test terminated when battery pack reached 7.2V under load (=0.9V per cell) at 2 hours 39 mins.

Total battery current load at termination of test = 810mA (405mA per light).

Pack bounced back to 9.4V off load.

I’m happy 😀

Love to hear any comments.

Question for all you experts 8) … Now these light cases are only 38mm long of metal …. so the next test is to risk one at full power for an extended period…… at what case temp should I start to be worried for a no forced airflow test?

I was tempted to cut the case right to the edge of the alu L piece inside and make it a dinky little light, but didn’t, wanted to see how hot it got first.

I think that was a wise decision bigjim!

From what Troutie said earlier … I think 40C is no problem … but my little cases will get very hot at full power on the bench. I’m hoping that they will be OK on the bike while moving, even on full.

I’ve just got a new 8 AA cell set of 7dayshop “good to go” LSD 2100mA batteries …. when I’ve given them a few cycles, I’ll repeat the test above out of curiosity! Thinking aloud … I’ve also got some Vapextech 2900 NiMHs that are well run in …. could be a nice comparison.

I’ll leave the Sub-C 7.2V 3700mA NiMH pack out of the tests until I’m more sure of the light/drivers characteristics.

When the case starts to feel hotter than your tea when you drink it is as hot as I let owt get to .

if the light starts looking bluer then its nearly dead .

bearing in mind the leds will be 30 to 50 degrees hotter than the case assuming you have a good thermal path to the case

Full power and a walking speed airflow in the UK will keep it nice and cool on full on a case cut down to 50 mm long

Thanks Troutie …. gives me something to compare … I’ll make a brew (Yorkshire tea, of course!) and experiment! 😆

Built up my mk2 light today, it uses a slightly larger hammond case to allow me to fit 3 led’s. The case is made in 2 parts so sealing will take a little more effort. I have also had a quick play on the lathe and knocked up an ali heatsink to try and keep the temps down a little.

GaryS: Looks all good, whats the light like, any beam shots? What are you using as spacers between light and bracket?

no test yet, silicon is still setting. the spacer/heatsink is just a bit of round aluminium bar that i turned down on a lathe.

What a beast! Very nicely done, GaryS! 1000 Lumens out the front?

Did you spray or anodise the heatsink?

What length is the case (front to back) and where did you get the fibre(?) washers?

The heatsink is sprayed with car paint, probably wont last long but it looks nice for the photos 🙂 The case is cut to 50mm, and the washers are punched out from a little piece of thin rubber sheet i found.

Interesting, I didn’t know you could run more than two LEDs off the driver. Whats the handlebar mount garys?

I read in here somewhere that 3 leds would be ok assuming the input voltage is high enough. Hope i read it right! 😆

the mount is from lumicycle:
http://www.lumicycle.com/product/214/qr_lrg/qr-large-camlock-bracket.html

Cheers, looks a well made mount, I love how its still cheaper than the zip tie and plastic clip Exposure flog for a tenner for the joystick.

Mine works! Couldn’t believe it. Put the battery into the holder like I was cutting a wire on an h-bomb, was expecting an explosion of lithium fire and hydrogen and arcs of electricity, but it works fine. Just need to build the 4x holder, stick it together and seal it and its done. Have restrained from comparing to the P7 lights yet…

Magic when it doesn’t go “fizzzz” ain’t it! Well done BJ

GaryS … thanks for the info.

I got impatient and tried the “Good to go” batteries …… pretty much same results as my Eneloops …. almost to the minute. That’s good considering they have only been recharged once. So they may turn out to be worth the extra 100mA plus being nearly half the cost! I’ll reserve full judgement until they have been sat around in a camera or something else for a while!

Right, lads, just got the new batch of PCBs and have been running some tests. Difficult decision coming now… I was hoping to keep the costs under control by changing from the Diodes ZXLD1360 to the AP8803. This is a cheaper version but has a few draw-backs. It has higher losses which means more heat dissipation. I was hoping to counter this by using a larger PCB and to a degree this has, the temperatures of new and old are about equal but still a bit higher than ideal.

I’m thinking that I’m going to have to stick with the more expensive chip for the 1A driver and use the cheaper one for lower power ones. I can do an 830mA driver at the lower cost and 670mA ones will be cheaper still as I’ve managed to do some other cost savings.

The new 1A / 830mA drivers are 24 x 20mm, the lower power ones are 21 x 19mm. All have better control options with shutdown and reduced power (approx. 40%) modes built in.

Just need to get components in bulk now and get some built up. I do still have a few of the old design if anyone wants to take them off my hands…

Hi Stephen ….. a bit confused ….. so what advantage has the new design over the old? Mainly thinking about the 970mA/1A versions, but a summary of the changes for the lower current versions could interest others.

I might only be speaking for myself but a few pence extra as costs rise is worth it if it preserves or improves the spec. I guess if they rise to a pound or two extra, that would make me look at other options ….. as it is I’m happy with the current designs, especially at the size they are at. Keeping the cost the same at the expense of the spec would not be high on my list.

some great looking lights on here, Im trying to upgrade another old Lumi can but cant get a response from Trout, anyone now the best way of getting hold of him apart from his website link. Im after XPGs and reflectors

Hi Ranger,
He’s working in London this week so I guess he will have restricted tinternet access. He will either see your post on here and reply or email him direct to troutie @ blueyonder dot co dot uk. unless thats the address you have used.
I know he was having trouble over the last few weeks as not all emails where going directly to him but getting lost on his server.

Ive emailed him as well to let him know about you.

The old one ran a little bit hotter than was ideal, the new one has thicker copper and more area so will run cooler. I’d hoped it would be enough to allow me to use the cheaper chip as well, seems not.

The design is tidied up a bit, connections are further apart so less chance of shorts. You now don’t need external resistors for dim mode while keeping the ability to have the soft-off mode.

Main thing is I needed to get some more PCBs made anyway so the changes seemed worthwhile. The smaller boards use a cheaper inductor as well as the cheaper chip.

I’d worked out prices for them all but have left the spread sheet at work. I believe the 1A version would be £6, 830mA £5.25 and 330/500/670mA versions maybe £4.50. Will have to post tomorrow.

As usual 10% discount available for direct payment for forum members but don’t send any money yet, they aren’t ready!

(900?)

He! He! You got 900!

Thanks for the info Stephen. Sounds good … old chip, but a bit cooler, wider spacing on the terminal pads and still under (just on?) 20mm. 8)

p.s. you got my message about the new switches?

I’ve just mic’d up the board and it comes out at 24 x 19.7. The residue of the ‘nibs’ (what holds the PCB panel together) can increase this slightly but they can be filed down if size is critical.

I’ll try to find my camera and do some pictures.

Not got your message – which address did you send it to and when?

19.7 …. that’ll do it 🙂

ntlworld one

I can resend if you can’t find it. Thanks

I’ve got three ntlworld addresses… If it was today not received it on the blackcattech one, if it was earlier then I’ve either not received it or somehow it hasn’t registered, sorry!

No prob …I’ll resend it on this forum one now.

Got it, now it’s telling me I’m not allowed to send you email….

I’ll keep trying but to summaries, yes I have a few spare. The M6 thread is about 5.8mm OD, the ‘standard’ thread is about 6.1mm. M6 is also coarser if that helps you work out if they may fit.

Most bizarre! Ah! Just got one off you now. I’ll respond off forum.

Just wanted to say a big thanks to BCT, Trout and everyone else on this thread. Got all my stuff and built up the light, certainly not the cleanest build I’ve seen on here, but somehow it works 🙂 really impressed with it.

Thinking now I need a new light for my bars as the DX P7 torch I currently use doesn’t seem to cut it now. I’m thinking two 3up XPG’s, but not sure if that would work ok. I’ve got some computer heatsinks which I think if I used inplace of the l-shaped aluminium could be enough to keep it from melting, but not sure what reflectors/lens would be best to give a good flood style light. Any thoughts would be appreciated.

Cheers
Kev

Kev79

you will be going from 2 leds to needing either a more expensive Boost driver or useing 2 of BCTs and a larger battery .

their will be no usfull reason to use a finned or needle computor heat sink inside the housing as you need to get the heat to the outside as fast as poss .
and 2 triples will get hot fast .
if using the hammond case then try and find some U channel that is a nice tight fit and you would then need to add extra sinks to the outside of the hammond

The standard Carclo 20 mm triple tight narrow is still a good flood used with the triple XPG .

a good bar light in the Hammond would be one triple and one single with the same reflector IMHO
but would be a bit more complex to build

Hey GS, I’m impressed with your work…insulation washers a nice touch, I’m gonna copy that.

Your unit reminds me of the film ’wall-e’

I own an extensive dvd library 🙄

In preparation for the new drivers (parts should be arriving tomorrow from Digikey including another batch of 18650 holders) I’m clearing out my old stock. I have:

6x dim-mode drivers (970mA)
2x standard drivers (970mA)
1x DIY kit (driver, switch, power plug/socket)

Drivers £5.20, kit £8. A quid P&P flat rate. Any that don’t go by tomorrow evening will go on eBay.

Kev – as Troutie says, no use having the heatsink inside the box as you just heat up the air inside. Attaching one to the outside would be very useful though – fins and pins increase the surface area drastically and are especially useful when moving. Use a good thick piece of alu inside to get the heat away from the LEDs and to the case.

For three XPGs you’d need a 12V battery with my drivers. A triple lithium might just manage it but you’d be running close to dropout. I found that three P4s needed about 13.5V but they were running at about 4V / LED compared to about 3.3V for the XPG.

Oh, by the way, I’ve just bought a bag of 100 M3 x 12 polycarbonate screws and nuts from Rapid which should be very useful for avoiding shorts. I can include these in future kits if there is interest – not sure about the practicalities of selling them in 4s as they are so low value the hassle factor would be high for the money.

OK, I’m late to the party…

Mr Trout, did you get my mail?
Mr BCT I need drivers + bits and pieces to build 2 lights.I intend to build one helmet mount and one bar mount light.

So if I’ve got this right I need:
4X reflectors – Mr T.
4X LED – Mr T.
2X Cases – Mr Maplin.
1X Bar mount – Mr Lumicycle.
1X Helmet mount – Mr?
2X Switch – Mr Rapid.
2X Jack plug (male) – Mr Rapid.
2X Jack plug (female) – Mr Rapid.
1X Battery mount for internal fit – Mr BCT.
1X Battery mount for external fit – Mr BCT.
1X Battery bag for top tube – in stock.
?X AA batteries – Mr?? or Mr Smudge?
2X Heat sink – in stock.
2X Polycarb sheet – in stock.
1X Heat conducting adhesive – Mr??
Various bis of wire,screws and flex – all in stock.

Anybody care to fill in the blanks?
Regards
Marko

Marko – I’ll check what I’ve got when I get home tonight. I think I have spare switches and boots, just short of the power cables. I’m ordering from Rapid over the weekend anyway so can get what bits you need.

Troutie will probably confirm but I have a feeling he found the case was too small to fit 2x 18650 inside. You may get something like 3x CR123 which would be about half the capacity of 2x 18650 and if you are using two you could probably get away with running it on low power most of the time.

Marko cant find any mails from you in any mailboxes

have got the parts in though .

Batteries will fit in but the holders wont .

one triple and one single is tempting. I’ll finish this one and see how it is first!

Troutie and BCT.

Mr Trout, YGM.
Mr BCT, I’ll just go for the easy external battery option then. Please mail me when you have checked your stock (markostoreyATgmailDOTcom).
Thanks for the replies
Marko

im liking that triple led badboy! youll burn retinas from miles away.

considering building another as a bar mount but would defo want it floodier. anyone got any links to reflectors? i found some early on in this thread but i didnt bookmark em 🙄

Just received another 10 each of the twin, triple and quad 18650 holders. Prices as before (i.e. I can’t be bothered to dig back through the thread so you’ll have to check for yourself!)

Is there likely to be any more demand for kits? They have been fairly slow moving so I’m wondering whether to get more stock of the power leads etc.

Hi Stephen …. sent email message on 18th on same address as other messages I sent …. did you get it?