P60 XML - which one to buy?

Wow Don - a million thanks!

You've just made me a lot more comfortable with purchasing the dropin. :)

Just one more question - how long do you think I could run the Manafont XML on high with the aluminium foil wrapping before it gets too hot? If it gets too hot to the touch it may be too late for the LED and driver or is there a "grace period" before they become damaged?

A big thanks from me too Don. I've always wondered but never wanted to ask so thanks for asking Haggai. Smile

Don thanks for the guide with photos on how to correctly foil wrap a drop in. Greatly appreciated.

I am interested into knowing that too. Will resist 1 hour torture test on HIGH while it draws more than 2,8Amps?

I do, no single host i have has the excact inner diameter. There is a slight variance withing same type/version hosts as well.

Thanks Don for the excellent pictorial guide. Alternatively I was wondering how effective will it be if we wrap it with thin copper wire. Did anyone tried this?

That was fast... ordered yesterday evening from Manafont, and now I got a shipment notice with registeration number.

Thanks Don! Can we make that post a sticky?

I got my drop in on Monday, haven't had time to do anything yet. Well, my cells, dmm are not even here yet.

About the length of time the battery charge lasted - 40 minutes. Less if I wasn't using my hand as a heatsink. If the snow stays away I'll find out next week as I hope to be off into the wilds with the assistant to annoy the local wildlife and do some longer-range beamshots. About 1km from here.

Last time I went there was great weather every day, but as soon as it got dark, it rained every time.

I honestly don't know if that would be better or worse. You would have to be careful that the wire didn't go to places it shouldn't but a blob of solder would hold it in place. It might take a long time to wind it neatly and tightly - you would probably want to use very fine wire so you could stuff as much of it into the gap as possible. If you do try this, I would love to hear how it worked.

Make sure it is tinned or plain copper wire, not the enamelled stuff used for winding transformers and inductors - the enamel would be a very poor conductor of heat.

What we are trying to do is to replace any air gap with metal so a tightly wound dropin ought to conduct heat away from the dropin very well. Once it is wound, dipping it in solder (After masking off everything you didn't want soldered) to keep the wire in place and fill as many remaining air gaps as possible ought to give excellent results.

What does that mean? The driver would shut off the LED if it got too hot?

Oh, you just made me want to go back to Scotland... Been there only for six weeks, but it was splendid and I really want to come back to all the wonders of this land that I've seen (and tasted! :) ) and to fill in what I've missed (the Outer Hebrides, Shetland, and many isolated places I could not get to with public transportation). I really enjoyed the nature, castles, people, highland games and the taste of whisky, and I even learned to play pool (by an englishman at my hostel). Hmm... must go back there. :)

No, I'd not be very happy to let pretty much any light run a battery empty on full power without some sort of heatsinking. Your hand is good for this as your blood will take the heat around your body. Quite a lot of lights can become painful to touch of you don't let them lose heat through your hand. The Ultrafire C3 SS will become painful to hold in about three minutes on high with a 14500.

40 minutes is about as long as a typical 18650 will run one of these on high. Most drivers won't shut of on excess heat - the only ones I can think of that do are the Ra lights ones but those aren't remotely close to budget lights. Some of the more powerful Fenixes may do.

I want to do a runtime on these anyway so will charge up a cell and keep an eye on temperatures while I do so. Unfortunately I can't log temperature at the same time as output but I have some ideas for that which I hope to have time to play with next week. What I really want is a thermal imaging camera, which my brother's company would be happy to sell me - at the price of a good new car.

4530 lux at switch-on.

Temperature of head at switch-on 18.7C. This is the foil wrapping as seen in the pictures above.

At 1 minute 24.9C

3 minutes 32C - output down to 3800lux.

5:30 39.8oC

Here is the setup.

The meter on top of the lightbox is measuring microamps from the solar cell at the far end of the lightbox that I use for output and runtime measurements - it is connected to the PC you can see on the far left of the picture. The meter on the right measures lightbox lux which I divide by 892 and multiply by 160 to arrive at "my lumens".

The meter on the left is measuring temperature. There is a small thermocouple taped to the head. In theory I ought to be able to attach both meters and log data - in practice the £W@$%%$^& Windows drivers only see one meter at a time and it appears to be completely random which one.

10 minutes 50oC 3560 lux

The foil is working. Even the tailcap is getting hot. I will stop at 60oC as the internals will be getting a lot hotter. Normally I would point a large fan at the light while doing runtimes on high.

14 minutes 54oC 3500 lux

I think most digital cameras can pick up infrared (maybe you'll need to take off the internal IR filter), so you could make a "poor man's thermal imaging camera" by using a filter that passes only IR, and use time-lapse photography or even record a video of the flashlight.

You can perhaps get the temperature values by using fixed exposure settings and calibrating the gray level with a known temperature heat source and a non-contact thermometer.

But that's a lot of work and I have no idea how accurate such a device can be...

17 minutes 58oC 3420 lux

58oC is painful to hold for most people - if it is in your hand it will not get quite so hot and it probably hasn't reached LED damaging temperatures. You will know when the driver hits 160oC - the solder will melt and it will fail.

19 minutes 59.5oC 3380 lux

20 minutes 60oC 3360 lux

I switched it off at 20 minutes. In your hand it might be good for 25 minutes till it became uncomfortable to hold.

I will let the light cool, let the battery cool, recharge it and remeasure the output.

The test was done in an old-style Ultrafire WF-504B which is a clone of the Solarforce L2, but is lighter. The Solarforce body might give slightly better thermal results as it has more mass.

Hi folks. How do you see this idea?

P60 + XML T6 led. Driver = kaidomain 8x7135 (2,8Amps)

Also, cover the dropin with aluminium foil.

If I am not wrong, on HIGH mode it feeds to led 2,8A (800 lumens). On MED 1A (300-350 lumens)

So, a solution can be, keep the light always on MED (300-350 lumens) and use HIGH (800 lum) for short periods? 300-350 lumens is a respectable amount of lumens.

What do you think?

Run on HIGH lets say, 10 minutes, and switch to MED for 5 minutes to cool...

Agreed entirely.

From my measurements it is OK for 20 minutes on high. Which is probably around half the charge of the cell anyway.

Well, the final question. With the trick of the aluminum foil....will be enough for cooling? will the led fail? or decrease efficiency?