As long as you stay on medium mode it should be fine. It may get uncomfortably warm but they are not hot enough to kill your light slowly.
You can consider the slightly pricier Convoy S4 if you are worried about heat. With the extra holes for catching air in S4 you may risk waterproofing but it should handle rain no problem.
I do want a,waterproof light for sure.
Check the length of the cells, this is the place to look:
http://lygte-info.dk/review/batteries2012/Common18650Summary%20UK.html
Note also that some Convoy lights come direct from Convoy, others may have been through some third party and may have different springs, different drivers, whatever they can cut a corner on.
You can rely on lights from MtnElectronics to be as described and get them built to your needs.
You want firm spring contact (and likely some “bulb grease” conductive gel at the contact).
Make sure the ends of the springs are bent round to lay the maximum length flat against the cell — not just a single sharp point of contact that digs in.
Also look up “carclo elliptical” optics — MTBR.com is full of helpful info. Those give a long flat oval beam instead of a round one.
What about vendors such as aliexpress and gearbest?
Gearbest is questionable as to quality and shipping- they have sold fake lights and cells and many shipping problems have been spoken of lately. Aliexpress is similar but Simon, owner of “Convoy”, sells there- his listings and service are real and top-notch; other sellers beware. The upside is sometimes very good prices if you aren’t in a hurry to get your product.
Before I purchase from either place I look to see what experiences others here have had with it, heeding only the latest posts as product manufacturers and vendors change stock and specs frequently for more profit; often A real product will not be sold for more than a month before fakes start being shipped. And fake cells can be very dangerous; at the least they do not perform as expected to. At worst they can go ‘boom’.
I still do business with both but I have no expectations and I recommend that everyone see the Chinese Mega-stores from that perspective or you will be disappointed.
Phil
If you are new to 18650 cells , you could get the Eagle Eye X6R
This light charges the cell inside so you will not have to purchase a separate charger. Well for now, soon after joining this forum you be finding (buying) all sorts of things you’d thought you’d never need.
https://budgetlightforum.com/t/-/33113
Also JetBeam has the “C8” with built in charging and a cell included.
Good luck!
So I need advice. My wife is asking me for gift ideas for me so I am looking at mountain electronics to give her the specs for the convoy and the tint I want is out of stock on every model. All this talk of counterfits and dangerous fake batteries has me leary of where I am ordering from. Can someone list other reputable dealers that I can trust sell genuine stuff so I can try and get good batteries, a charger, and my genuine light all from the same place? Thanks!
Email or leave a message for Mtn and ask when they could have something in that you want.
They absolutely don’t list as available anything that isn’t right now available. But it might be tomorrow.
They also generally can tell you when something’s likely, and have a “notify me” button for automatic email notice.
And if it’s not going to happen in your time frame, I expect you’ll get a straight answer. Do ask.
I have had good results from Mountain Electronics, Battery Junction and Banggood.
Avoid batteries “*fire ” they seem to be the most counterfeited brand.
I am a novice here myself, I use the Nitecore Intellicharger I find it useful for charging my 18650 cells.
For mountain biking I like the neutral white tint. Not the cool white. On the handlebars look for a flood beam, and your helmet go with more of a spot.
I use the Fenix BC30 on my bars and a Leyzene Superdrize on the helment, soon to have the JetBeam GTbr10 on my helmet.
One thing I know there is always a newer better light out there.
The C8 or S2 lights will get you started, don’t worry there will be always be some other light that you’ll want.
Are you familiar with the term ‘white balance’? Your brain attempts to adjust the input it gets from your eyes for optimal detail, color perception and contrast. Contrast is the difference between the darkest and brightest spots in your vision, so if you introduce a very bright light source like a 1000 lumens LED, the weakly lit parts (outside of lightcone) of your vision that used to be in the mid range (brightest being the moon, an incandescent light, whatever), get shifted towards the lower end of the spectrum where they are filtered out. Same for brightest parts, you’ll see less or no details in a flashlights hotspot compared to the spill cone around it (unless the hotspot isn’t the brightest light source in your current area of vision).
Jetbeam also has a bicycle specific light, the BR10GT, comes in around $44 from most retailers. Amazon had one listed at $39
I am learning quickly. Thanks for elaborating.
I think you’re better served by a “floody” beam so that you can also see hazards to the sides as well as be more visible to the sides yourself. Something with a less focused hotspot would be my choice. A concentrated beam will ‘wiggle’ across your path with normal handlebar movement which to me is disconcerting while a wider beam won’t. With enough lumens you’ll still have enough light as far ahead as you need.
I don’t have one but a ConvoyS2+ seems like a good choice for this, the beam profile is similar to my A6 which I’d consider ideal, but that’s more a ‘hot rod’ than a light meant for hard service. Real Convoys from Simon at aliexpress or from FastTech. I like the latter as they have many more emitter options listed so you can get the tints/ lumens output you want. Get cells from Mtn Electronics, always genuine and he only sells the really good ones. Xtar MC1 charger for cheap and simple, or Xtar VC2 for a comprehensive charger at a good price. Shop carefully and all can be had for around $50 or less. Cells and chargers useful for the other lights you’ll find yourself buying so a good bargain indeed. (Oh, we forgot to mention this hobby is addicting so plan for more lights now :bigsmile: )
Phil
As mentioned the “spot” will be a bit jumpy; the S2 reflector is deeper and gives a tighter spot than the S2+
Either one can be modified to a wide angle optic with this sort of lens:
more general search for various sizes;
(free US shipping, inexpensive, very nice effect)
(in Europe look for Ledil products, same kind of thing)
If you only want to spend <$50 in your light, i would recommend:
YinDing 900lm
or
Nitefighter BT21 1800lm
or
Nitenumen BC-A2 1100lm
with
Solarstorm 2S2P 18650 Battery Case
or just
Fenix BT20 including BA4C Case for 2x18650
fenixlight.com/ProductMore.aspx?id=16
It’s ordered but it is my Christmas present so I will have to wait. I ordered the s2+ and a pair of Sanyo ncr18650bf cells and a Soshine sc-s2 dual channel charger. I hope I bought the right stuff! Why can’t all 18650 cells be the same damn dimensions lol! Man researching all these batteries was intense. Ot like the good old days when you just went and bought an 8 pack of energizer AA batteries at Wally World lol!
Because (1) there’s no standard construction yet — manufacturers are trying to come up with a design that is safer and longer-lasting, and
(2) none of them come with a circuit to protect them from overcharging or over-discharging, both of which are unsafe (see (1))
so (3) there are a lot of aftermarket third party addon circuit boards, some of them good, tacked on and shrinkwrapped, to make them safer, plus
(4) there are a lot of fakes and variations out there
Can anyone paste some reliable links to a NW (perhaps even a WW) version of S2 and S2+, and some decent and recent budget 18650s? Something in the range of pink Sanyo 18650s from ~3 years ago? Or better, of course, but same price/performance class as these were 3y ago? 
Thanks,
V
These are the batteries I bought. SANYO CELLS Don’t know a thing about them but I saw you mentioning Sanyos. I was so nervous about which batteries to buy because I didn’t want counterfits that would blow up in my face etc. Researching told me that Panasonic made Sanyo cells. In fact I think they may own sanyo.
I forgot to ask early on. Can you leave 18650s and other Li Ion batteries in devices for the same amount of time as a standard alkaline without being used or is there something different about these batteries that warrants them being removed if going unused for weeks at a time? And can you use automotive dielectric grease on threads, orings, and battery ends of a flashlight?