Driver selection for dual XHP70

I currently have a modified Thrunight tn36 powered by a 5000mah hardcase LIPO but I am looking to make something lower profile and better heat sinked

This thing is way too bulky, and it either thermal, or times out of turbo

I am thinking with two XHP70 driven hard and cooled, i can get near the high setting of the triplet.

Im new to the electronics portion of this
I have two xhp70 chips 6v,
I am open to parallel or series
batteries will likely be Lipo but im open to 2s, 3s, 4s.
but one thing is for sure,
I need to drive these bad boys as hard as i can while being able to run them for roughly 1-1.5 hours at a time.
can anyone reccomend a driver configuration that will allow me to do this?
I have an adventure sports driver currently but its apparent that this is wholy insufficient for driving these things to their potential.

Any advice would be appreciated
Aaron Englert.

Driving a xhp70.2 hard generates a lot of heat, remember @6v and 5A you’re needing to dissipate 30W of power. I’m not an expert with multiple xhp70.2 setups, but I think you can do something like a buck driver and run 2 6v emitters in parallel off a 3S lipo. They will still generate a lot of heat in both the buck driver and emitters so cooling is essential, or get a driver with thermal regulation. For drivers check out mountain electronics or hop on kaidomain or Aliexpress and search xhp70.2 driver.

thanks sirstinky

I was looking at buck drivers on MTN, and I think one will work, but I can only get 4A at 12v or 5A at 6v, and i am thinking that’s not quite enough…

Sure. Im all for more power, but figure that even at 5A a P2 1A binned 70.2 is making nearly 5000 (or more) lumens, so x2 that’s 10k lumens. Even at that relatively tame drive current, in a small housing managing heat will be very difficult without constant stepdowns so you need a way to actively cool it or you’ll start throttling immediately and decrease brightness. You also need a way to cool the driver since it will also get hot quick.

If you are trying to get much throw out of an xhp 70.2 you’re into a large reflector or optic. The xhp70 aliexpress reflectors for a C8 probably won’t cut it. A 38mm Ledil Suri optic is 6.6cd/lm and might work. Once you get into that size of light body keeping it cool while moving should be manageable with some heatsinking.

Two seven emitter anna spot optics with sst-20 leds or xpl hi might be a better option. They also make a medium optic to help tune the beam pattern.

A Gemini Titan or Magicshine Monteer might work but they are made for mountain bikes and may not throw far enough. Kaidomain sells a xhp70 mountain bike light that may work if you double up on the sense resistors. Fairly bulky but its cheap.

Too much light can be quite painful and blinding if it gets reflected back into your eyes. Signs, foliage, dust and snow can do it. Those things have gotten me while mountain biking, they haven’t caused me to crash yet but the risk is bigger at motorized speeds.

If I understand correctly
If I do a series of 2 6v xhp70, supplying “12v” @ 4a, each will see 4a

If I supply 6v @ 5A to parallel 6v xhp70 then I will only get 2.5A which won’t be close to what I’m going for.

I’d like to be able to get close to 5A to see how hot it will get and work back from there to get the highest setting that will work

Well the tn36 moto version i showed makes any bike light I’ve come across cower…
But that much weight on a half shell is terrible.

Can keep a good pace on technical decents.
On the motorcycle I really use the light only a few times a year and it works well. Obliterates the setups like the “task racing” light that the baja guys use.

The only bike lights in the league I’m going for are the cateye volt 6000 and the Betty r lupine both are like 800usd

It must be ultra compact for helmet mounting.

Having the light higher(to reduce hole shadows) and pointed where you are looking is a must if you want to run race speed

Plus it somewhat already exists

Excuse the rough machining just wanted to make it fit didnt want to fade as I plan on making a much nicer one.

Big power, decent throw, light weight and small is not going to be easy. If you haven’t done so already measuring your existing light with a lux meter and then figuring out what light intensity you are targeting would be a good start. The major optic manufacturers show the cd per lumen for each tested led so you can work out how many lumens you need to produce. Unfortunately I have not found a good formula to predict how adding more lights affects the throw or beam width.

Cree has a tool for showing lumen output and electrical charactaristics. If you over drive a small number of led’s they start becoming very inefficient and run hot , and as the led operating temperature increases the efficiency drops again.

Lexel is a member here that sells a lot of drivers and has modded quite a few lights. He’s not been very active here lately but pm’ing him might be worthwhile.