First of all, I apologies for my complete ignorance on this matter, although I’m hoping some knowledgeable and kind-heated souls will take pity and help me to broaden my horizons!
I own a bike light called a Bikeray III V2 which is a pretty good little light with a good spread that’ll run for around 4 hours in it’s current form. If possible though, I’d like to uprate the LEDs to something a bit more powerful/efficient without losing more than half the battery time. I use it for mountain biking and it really does seem a bit underpowered, especially in the wet when the light reflection is lower.
Is it possible to just replace the LEDs or do I also need to replace the driver and possible battery to uprate the output? I’m on a bit of a tight budget so I can’t spend too much. Hopefully the heat dissipation would also be able to deal with uprated LEDs…
Here are the specs for the light:
1300 Lumens 3 LED Cree X-PG
4.4 Hours Run Time @ 1300 Lumens
LED: LED3 Cree XP-G R5
Reflector: Mould optical glass lens
Over heat: High temperature protection driver board
Power supply: 4x 18650 battery 5.2AH Battery
Casing Material: Aluminium Alloy 6061 Aircraft material
Water proof: IPVI
Certification: CE/UL
Run time: Hi 1280 lm 4.4 hrs; Low 600 lm 14.4 hrs & Flash 1280 lm 150hrs
Charging time: 4 hours (standard charger)
And here are some pics:
Any advice would be greatly appreciated. I’d really enjoy having a go at this if possible.
You could just upgrade the LEDs to XPG2’s, or XPL for even higher output(probably have to modify optic to fit) add extra heatsinking, and add another sense resistor or 2 if you want more output with a little less runtime
At the risk of being an annoying noob, I don’t suppose you could you direct me to anywhere that might explain the purpose of and how to add the sense resistors, and how to uprate the heat sink? I’ve done a fair bit of looking around but can’t find any material that explains the process, probably down to my lack of experience on the subject matter and not wording the searches correctly.
Have a look at Help with Current Sense Resistor Modding but if you just type ‘sense resistors’ in the search bar you’ll find some threads about it.
Heatsink wise, mount the leds on a copper MCPCB and just get some copper to put behind the MCPCB, then some silicone thermal pads on the driver
Upgrading the LEDs wouldn’t do much wrt output without modification of the circuit too. The XPG2 LEDs are a little more efficient than XPG but the difference would hardly be noticeable. The XPL LEDs can handle a lot more power but have a slightly different shape from the XPGs so are not a dirct replacement. As mentioned, modification of the optics would be necessary as well as modification of the circuit if you want noticeably more output. Reducing the resistance of the sense resistor would potentially increase current to the LEDs. The white thing the LEDs are soldered to is the MCPCB (sometimes referred to as the star,) which looks like aluminum in your case. A copper version would transfer heat to the body a lot faster than aluminium which would be nice for higher outputs.
Approximately, what is the diameter of the star from your light? If you can buy a star with three LEDs already attached, that would make life a lot easier. MTNelectronics sells triple stars that may work.
That’s sounds like a good plan. The diameter of the star is roughly 24 mm. The XPLs would be an interesting option as long as the battery wasn’t drained too quickly.
Cheers for the info - I’ll check out MTNelectronics and see what they have. If I could get a fitted out star for not much that would , as you say, make life a lot easier!
Would anyone be able to direct me to a UK based supplier who could supply the XPL LEDs as well as the additional R100 and R120 sense resistors? I’m also struggling to find a direct copper replacement for my current 24mm aluminium MCPCB so if anyone could assist, I’d be most grateful.
Also, is there an easy way to remove the current MCPCB without damaging it? It’s bonded to the light housing, presumably with some kind of thermal grease/glue. Speaking of which, I was thinking of using some thermal grease (used for computer processors) to help transfer the heat to the housing if I do upgrade the star. Has anyone else used this before?
I’d love to have a crack at this and apologize once again for my laymen questions.
I can supply you some XPL’s and some sense resistors if you like? If got a few different values including r100 and r120
Best way to remove is heat but you could just pry it out, sounds like thermal epoxy that’s holding It in, I’ve also got a triple star but it’s 20mm if you want to try it
