I'm looking for a flashlight which I plan to use on my bike. I have a mount for it already.

Looking for output in the 40-200 lumens range with 4h+ runtime. Obviously "more" is "better" but obviously there is a tradeoff between output, runtime and size. I want reasonably small. I'm considering either single AA or 18650 but if the latter it has to be USB rechargable in-light as I don't want to carry another charger.

For manufacturer I'd like to go for a Chinese brand that has a good reputation, the likes of Fenix would be perfect, I have had found their lights to be exceptional in the past. I'm not interested in the likes of Surefire or Maglite (way too expensive) but neither am I particularly interested in the likes of Ultrafire or "Police", i.e. the sort of flashlights I have seen about the place in night markets (way too cheap). I'm open to other quality Chinese brands like Olight or NiteCore.

Ideally I'd like to go to a physical shop to get an idea of the size of the thing, as it has to fit on my bike, but I can compare with lights I've had in the past.

The only physical shop I'm aware of currently is Tank (http://www.e-tankstore.com), who have a number of branches in central Bangkok shopping malls.

Online, I'm aware of:

http://www.tacticalthai.com (online only, no shop, I emailed him)

http://www.fonixlight.com/

Lazada and CDiscount also have lights

Any other idea of physical shops that sell flashlights in Bangkok?

My price range would be around 750-2,500B depending on the specific light.

I bought a UltraFire small Chinese flashlight w/one 18650 and variable focus length; very good for lighting up a 2x2m area some 20m away. Price was about 700 baht as I remember. Has worked well for about 6 months now, got extra 18650 batteries from Amazon in USA. Need to use external charger and the one that came with the light seems very inadequate but am awaiting arrival of proper charger from Amazon. Bought the light from a small shop on ground floor of Pantip Plaza in BKK, fairly typical of the small camping/military vendors around here. Have never seen the USB recharger version you are wanting around here, but they are common in the headlamp versions such as one I have.

Thanks for that Keen, I think I've seen that light already in some of the markets, even in a rechargeable version.

I'm willing to spend a bit more to get something that will be rock solid reliable for several years and that I know what the efficiency of, as a cyclist maximum efficiency (lowest possible weight for the output) is important to me.

Ultrafire can be good, or can be shit, it's a bit of a mixed bag. I've used their batteries extensively certainly. Looking for something marginally upmarket this time, I have subjected Fenix and Olight flashlights to years of abuse without failure while Ultrafire can be a bit more fragile.

I bought a UltraFire small Chinese flashlight w/one 18650 and variable focus length; very good for lighting up a 2x2m area some 20m away. Price was about 700 baht as I remember. Has worked well for about 6 months now, got extra 18650 batteries from Amazon in USA. Need to use external charger and the one that came with the light seems very inadequate but am awaiting arrival of proper charger from Amazon. Bought the light from a small shop on ground floor of Pantip Plaza in BKK, fairly typical of the small camping/military vendors around here. Have never seen the USB recharger version you are wanting around here, but they are common in the headlamp versions such as one I have.

How did you get manage to get the 18650 batteries shipped by Amazon?

I thought loose lithium ion batteries were banned completely by USPS, airmail and all couriers due to spontaneous fire hazard. Most seem to restrict to batteries installed in device only not more than two per package.