Anyone tried to boost a Ryobi P705 flashlight?

6 posts / 0 new
Last post
bcm00re
Offline
Last seen: 3 weeks 5 days ago
Joined: 07/19/2019 - 01:00
Posts: 143
Location: St. Louis, MO
Anyone tried to boost a Ryobi P705 flashlight?

Has anyone tried to upgrade this light? It has a Cree XP LED on a heatsink and has plenty of battery so not sure why the output is only a measely 130 lumens.

https://photos.app.goo.gl/7JoBWSK6ab1xkM5a9

https://photos.app.goo.gl/DkTAkpw1qaGYmWie9

https://photos.app.goo.gl/psCzCEkHroJpQk6Y6

https://photos.app.goo.gl/BcFyhUL5ZDj5vs2D9

Sirstinky
Offline
Last seen: 9 hours 14 min ago
Joined: 11/02/2018 - 17:07
Posts: 1378
Location: Vancouver, WA

It’s probably an xpg3 from the photos. You could drive it harder than that, but on the aluminum mcpcb I wouldn’t go over 2 or 3 amps without aggressive cooling. You’d need a buck driver capable of dropping 21v down to 3-3.3 v. You can get a cheap DC-DC cc/cv buck converter on Aliexpress or eBay and just remove the factory driver and wire it in and see what happens. You’ll need a DMM or clamp meter to adjust the output current before connecting the led or you may fry it. Would be a good tinker project…

bcm00re
Offline
Last seen: 3 weeks 5 days ago
Joined: 07/19/2019 - 01:00
Posts: 143
Location: St. Louis, MO

Before I cracked it open I thought the LED would be the issue, but then started to wonder after it appeared to be a Cree. I have several DC-DC buck drivers laying around already so I’ll have to see if any of them fit. Any idea about how many lumens I could expect if I ran it at 2-3 amps? I guess I could consider installing a very small fan too (as the outer casing is already vented).

iamlucky13
Offline
Last seen: 13 hours 36 min ago
Joined: 06/22/2018 - 09:18
Posts: 1024
Location: USA

2A should be around 500-600 lumens out the front.

If it was me, I would also put a warmer, high CRI emitter in there.

Sirstinky
Offline
Last seen: 9 hours 14 min ago
Joined: 11/02/2018 - 17:07
Posts: 1378
Location: Vancouver, WA

At 2-3 amps, maybe 450-500 lumens? It depends on what xpg3 is in there, could be a cool white. Either way, they have a low vf (forward voltage) so controlling the current is important especially from power tool batteries. As suggested, once you get it working with the new driver, maybe swap that emitter out for one with better beam quality and one that will be happy at 2-3 amps like a neutral white XML2 or Samsung LH351D high cri.

bcm00re
Offline
Last seen: 3 weeks 5 days ago
Joined: 07/19/2019 - 01:00
Posts: 143
Location: St. Louis, MO

I did some testing tonight. The stock circuit is driving the LED at a shade over 2.9V with the current being about 0.45A. It does not appear to be limiting the current because when I drive the LED with the same voltage (from my power supply) I see the same current. I did try driving it with 3.3V and that bumped the current up to 1.9A — but the heatsink got really hot quickly. The output was brighter but not enough to warrant trying to add some forced cooling. After experimenting around I feel like this light in stock form is actually outputting more than the 130 lumens the manufacturer claims.