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WOW! Those pictures are awesome! Thank you for the review! WRT heat, getting hot is a good thing actually, it means the heat is getting out however, stainless steel is not a great thermal conductor so imagin if the outside is so hot, how hot the pill would be! >)

Lovely photos. Yup, SS is pretty but it does not handle heat well.

Great photos! Thanks for the review. SS lights need to be driven with lower current. The heat does not transfer away from the pill very quickly. The head will overheat in minutes. Even that stainless steel C3 light on a 14500 gets insanely hot after a while.

If you only knew how poorly… I mounted a large LED array on a stainless steel redacted and fired it up. The backside of the stainless was spit sizzlin’ hot. Two inches away it was room temperature.

I can well imagine. I have several SS AAA lights - the heads don't even get warm unless they have a brass pill. Too bad, 'cause I really like SS, but I won't buy one larger than AAA for that reason.

Thanks for the review f42. Your pictures are fantastic. I’m glad you like the light. SS certainly looks good.

Good job .

Post as many pictures as you want F42, they are fantastic!

So, does this light have a heat problem or not? Or, rather, how bad is it?

I have a Convoy S7 (2100mA) and two Convoy S3s (2800mA, 1400mA). I normally use them on medium, while biking. The S7 gets pretty warm during use (2100mA * ~40), while both S3s feel much cooler (even 2800mA * ~40). The 1400mA one can even tailstand indoors on medium without the body getting too warm.

So, the S7 head gets pretty warm… which means it’s pulling heat away from the emitter, right? Or does it mean that the aluminum S3 body is merely distributing and dumping the heat better? Since the S3 body stays cooler, could that instead mean it’s insulating instead of conducting heat?

I don’t have a way to measure the emitter temperature, only a vague feel of how warm the body is after biking with it for a while.

I’m just trying to figure out which model actually deals with heat better, so I can gift a couple and not worry about them burning themselves out.

Also, other thoughts on Convoy S7 vs S3…

The S7 has a rather deep reflector, which makes its spill beam quite a bit narrower. However, it also seems to have a more diffuse hotspot. So, the S7 fades somewhat smoothly and evenly from the center to the edge, with the spot and spill blending into each other reasonably well. In contrast, the S3 has a fairly distinct spot+spill pattern, with a bright center surrounded by a flat, wide spill.

I haven’t decided which one is better for biking… I like the S7’s smooth transition but would also like to have the S3’s wider overall spill.

The S3 accepts longer cells, while the S7 is strictly 65mm unprotected cells.

Personally, I prefer the look and feel of the stainless steel S7, but the S3 costs less and may be functionally more suited to my purposes.

The S7 is just narrow enough that a L2P clip doesn’t quite fit right. It goes on, and it works, but there is a tiny gap on one side between the inside of the clip’s ring and the outside of the S7 body. The S3, OTOH, fits the L2P clip much better (assuming you jam a paperclip into the tailcap to assure contact).

I guess I’m still searching for the perfect budget bike light.

Oh, by “2100mA * 40” I meant it has 6x AMC7135 for a max current of 2100mA, but the medium mode is driven at ~40 (or ~840mA). It seems like about the right level for biking. Low mode for indoor use, medium mode for biking, high mode for short bursts when more light is needed.

I got it mostly because I liked the stainless steel body, but was hoping it would also make a nice bike light. Looks like I should probably stick to aluminum lights though, and should order a S3 as a gift instead of another S7. I just have to decide between 1400mA or 2100mA, assuming the recipient won’t go above medium (~180lm or 270lm) for extended use.

Thanks a lot for the review! Frontpage’d and Sticky’d.

Can anyone say how the beam pattern compares to the Xeno e03?

If you guys think that Stainless steel is a poor conductor take a look at Titanium alloys in the Wikipedia list linked to above. It has about 25% to 35% of the thermal conductivity of stainless steel. I have machined and drilled 6Al4V Titanium alloy for making body jewelry and you have to go slow to keep from cooking drill bits and cutters because Ti is such a poor heat conductor. Very easy to cook cutters and drill bits.

From a thermal conductivity standpoint pure copper or silver heat sinks, including sterling silver, would be the way to go with pure aluminum next. Unfortunately the list does not include aluminum alloys but I presume they are generally worse than brass as brass seems to be used in many higher end lights. That might be due more to it’s easy machinability though rather than thermal characteristics. Pure aluminum and copper are a pain to machine due to their being soft and kind of gummy when trying to lathe or mill them. Hard to get a good finish with either. Choice of heat sink materials for lights is a compromise between thermal and ease of manufacturing characteristics.

Looking down the Wikipedia list actually diamond would be the ideal heat sink but I am afraid few could afford lights with diamond heat sinks until man made diamond manufacturing technology improves a lot. Another possible choice could be sapphire as silicon on sapphire has been used for some integrated circuits which required the best cooling of the die material. The Wikipedia article does not list it however.

Oh, I forgot to mention it, but I improved my S7. I like it a lot better now.

I still need to modify the firmware though, since 100% / 50% / 5% isn’t a very good mode spacing and it still has two groups (3-mode/5-mode) and an annoying blink on low to switch groups.

Also, I think I may need to do something to let the emitter stick a little farther into the reflector, since my modded S7 has significantly lower output than my modded HD2011 with the same emitter and almost the same power level. I think some of the light may be getting lost underneath the reflector. Regardless, it’s still one of my favorite lights now.

Dang I wish I would have read this before I just ordered mine, oh well might make a good hand warmer this winter. Will the pill fit any other convoy light?