A really, really easy 10 minute 18V power tool flashlight mod.

I have a lot of the cheap 18V Ryobi ONE+ tools. Originally these tools had Ni-Cd battery packs and they are total crap. The tools themselves are decent. They best part of the line is the availability of many, many different tools that can run on that same battery pack. I have 3 of the drills, a mini vac, 2 small circular saws, 2 radios, jig saw, , a couple of reciprocating saws and even a little table saw! What is not well known is that for a short while, Homelite made a set of outdoor tools that used the same battery pack and charger. In that line I have a tree pruner, chainsaw, and hedge clipper. Of all these tools, the most useful to me now is the hedge trimmer. the problem now is that the battery packs are all shot, and to trim some bushes, I would have to drag out 4! of the chargers and a bunch of batteries and start them charging so that when I started I could change out a pack every 5 minutes or so.
Why am I telling you all that?, well because I painted myself into a corner with this line. Here I was with all these tools and no batteries to run them on! On Black Friday this past year, Home Depot had a promo on the new Li-Ion ONE+ drill and battery and charger. Price was $39.95. I saw that and stood there for about 5 minutes, trying to decide if I should throw good money after bad and get 1. I certainly didn’t need another drill, but I could use the battery pack as it is backwards compatible with the older tools. Besides, this deal was the same price as the battery alone, and it included the special Li-Ion charger that I would need. So I bought 2.
Now the LUCKY part of this whole story. A friend of mine in Ohio, who has some 12V Ridgid tools, had a couple of his packs go bad. I offered to repair them (replace the junky Chinese cells that I know they contain) if he could find me some old Li-Ion packs for parts. I suggested he look in the recycle bins at his local Home Depot and Lowes for some packs. A couple of weeks later he called me to say he found 3. I asked him what brand they were, and he told me they were Ryobi. I shot right back and told him they needed to be Li-Ion packs, not the older Ni-Cad. He told me they were Li-Ion, it said so right on the units. Then he continued and said one of his sons was going to Rhode Island and he could drop them off with his spent Ridgid packs as he went thru Connecticut. Sure enough, a couple of days later I have his spent Ridgid packs and the 3 Ryobi’s in my hand. First thing I did was take the Ryobi’s apart and checked out the cells. All were Sanyo’s and one of the packs was the 10 cell version. I was surprised to find that all cells measured at 4.1V. Then I noticed that all 3 packs looked practically new!. Later I figured out that they must have been used in one of the displays at Home Depot, and when they broke down the display, they threw the packs in the recycle bin!
So now I have 5 Li-Ion packs for all my older ONE+ tools, one of those being a double capacity pack.
Back in business!

That’s the back story, now onto the 10 minute flashlight mod.
Because my ONE+ line of tools is now a viable option It turns out that in addition to all the ONE+ tools i have, I also have 3 of the flashlights. They are all incandescent and I NEVER even bothered to unwrap any of them because I knew they were not going to be that good anyway. Because my ONE+ line of tools is now a viable option, it would make sense to mod one of the included flashlights to LED. I know from past experience that some of the 12V MR16 LED bulbs can run on voltages from 12-24V. The 18V ONE+ packs could drive one of those directly with nod modifications. It happens that I had some nice MR16’s left over from another build.
My 10 minute incandescent to LED conversion.
The original light and new 18V Li-Ion battery and stages of disassenbly.

Next I un-soldered the spring and socket for the incan, the wires as is will reach the MR16 bulb.

With the old socket removed.

It must be that I am living right, the MR16 drops right in. Once again a perfect fit

So I wired the bulb in and glued it in place.

Now the question is, will 18V be too much for this MR16? As I said, I know that some of these MR16 bulbs can handle 12-24V, but the question is can this one. I searched the internet but could find nothing about the voltage range of this particular bulb. It’s a nice one with 8 Nichia 119’s for a total of 313 Lumen and a CRI 0f 83. I bought in on clearance for $1.25 at Lowes but I don’t want to blow it running it on too high a voltage. So what I did is ran it at increasingly higher voltages and measured the current draw. Here are the results of that.
8V - 0.35A
12V - 0.55A
16V - 0.39A
At this point it is apparent to me that there is some sort of PWM driver inside. The question is how much more voltage can it safely take.
17.5V - 0.35A
An “18V” Li-Ion pack is really 21V fully charged so at this point I ran it on the fully charged “18V” pack
21V - 0.3A
All seems well and good.
BTW, the original incandescent bulb draws 0.8A and is nowhere near as bright. After the glue dries I will post beamshots.

Perfect fit. Wow, looks like the bulb was custom built for the job. :slight_smile:

Good going lucking out on those basically new Ryobi liion packs. Reviving ur whole set of tools :slight_smile:

What kind of tool needs a 10 cell battery pack?

Also, nice mod. :slight_smile: Love me some MR16’s.

Nice effort and story. Looking forward to the night shots.

I recently got a Ryobi 3 piece Li-Ion set - drill, trim saw, & flashlight with 1 battery (it's a medium capacity I think - it's this one). Wife and I went out to the Pittsburgh Outlets and I went to a store called "Direct Tools Factory Outlet". Store was running a 20% off everything, with an additional 50% off items with orange stickers (I picked up numerous small items like jig saw blades, Ryobi replacement drill chuck, drill bits, etc. . . dirt cheap). So then I spotted the Ryobi 18v ONE+ lithium batteries behind the counter for $34 "reconditioned". Talked to the cashier about them and he told me they are mostly pulls from sets people return, all look like new. So for $27.20 I bought one. I probably should have picked up more!

I am curious to attempt this MR16 conversion in my Ryobi light.


It’s a snow day here in Connecticut and I still have 2 other hosts to modify. Yes that does look like that bulb was made for it. Actually most any MR16 should fit, so I will try another one. This time I will use this bulb, which can be had for a few bucks on EBay. Just remember that to run an MR16 on anything higher than 12V, it must have a driver.

Those 3 free battery packs that I got from my friend are worth close to $200. That was my favorite part of the story.

An 18V Li-Ion pack uses 5 cells in series for 5x3.7 Volts (18V). But we know that they are usually charged to 4.2V each or 5x4.2V = 21V.
In this case, a 10 cell pack has a 5S2P configuration for twice the mAh

It really took me 10 minutes to take the light apart, un-solder the socket and install the new bulb. However afterwards I spent 30 minutes on the internet searching for the maximum working voltage for that MR16 to no avail. Then I spent another 15 minutes running the voltage and current tests, and then another 1 1/2 hours typing up the post! :~
So in this case, The R&D and administrative costs, far exceed the manufacturing costs! :wink:

Hmm . . . a link to Ryobi battery capacities and some cell information.


Yeah those are the free batteries I got from my friend. The third battery was the double capacity like this one.
The 2 standard cap batteries are 2 for 99.99 and the double cap one is 99.99, so I got $200 for free. When I told my friend that, he said “Merry Christmas”!

I just made another one. This time with the very same MR16 that you already have, that you bought for the purpose of doing just this. I had to steal a driver from another MR16 and transplant into this newer style MR16 as the 1 piece triple MIR lense is much more attractive. As soon as the glue dries, I will reveal it to the world. If you will remember, the first new style MR16’s that we got had the proper driver already in it. The second batch I bought didn’t. It only had a full wave bridge and some current limiting resistors. It would not be able to be run on 18-21V as this flashlight uses.


The glue is has dried, here is a pic of my 3 babies. One stock, the 8 emitter and the 3 emitter mod.

Here are pics of the drivers in these cheaper MR16 bulbs. The first 2 pics are of a constant current driver, a pic of each side.

and now pics of a cheaper driver that does not supply constant current and is not appropriate for this kind of mod. Notice that it is a simple board with just 4 diodes for a full wave bridge and some current limiting resistors. This would not work in this application and the LED’s would be over driven at 18-21V

As of now, it is still snowing here is CT and we are house bound. I can’t go outside to do any beam shots, so here are some inside shots. I am not a photographer, so I don’t know how to take comparison shots. I do know that my camera adjusts for light levels automatically, so it is hard to compare one shot to the next. What I did here is shoot a wall that has windows to either side. As all 4 shots were done within a minute, the level outside each window should appear to be the same. In these pics, they do not because I believe, the camera is adjusting the sensitivity to accommodate the different levels of light output.
First no flashlight. notice the outside light thru the windows, kind of bright.

Next the original incandescent. Notice the light thru the windows, not as intense because of the hot spot on the wall.

This is the 8 Nichia MR16, The brightest of the 3. More flood than the incan. Notice even less apparent light thru the windows. This because even more light on the wall

Lastly, the triple emitter MR16. This is a warm white version, but it appears cooler than either the ican or the Nichia’s Once again notice there again appears to be more light thru the windows as this bulb puts out less light than the 8 Nichia’s

Can someone with more experience in photography clue me in on how to take more meaningful beamshots?

I certainly can. I do this for my reviews on e90post

What you want to do is take a control shot. You can under-expose it if you want (i.e. a little darker than it appears) but you don’t want to over-expose.

Then, you tell the camera to “lock” the exposure. On a DSLR, there are usually dedicated buttons for this (on my Canon EOS 20D, an oldie but goodie, it’s a button with an asterisk symbol). Some point and shoots (YMMV) may have a quick menu that allows this. You want to look for a button or menu that says something like AE-Lock, or AE-AF Lock. And even 3rd party camera apps (again, YMMV) offer this functionality (ProShot on Windows Phone, for example).

A tripod will be immensely helpful. You will be able to put the camera on the tripod, lock the exposure, and do your thing. Awesome for mouse-over images. I wish e90Post supported that, it would be quite awesome.

If you provide the camera model you own, I can do the research for you and tell you exactly what you’ll need to do to make this happen.

Awesome mod!!!

For those that don't want to tinker and still want a functioning light after the incandescent light goes kaput and want to upgrade to LED


The 1watt with the right voltage (7-26vdc) works great, I put one of these in my Porter Cable worklight that came a toolkit I bought from lowes...decent enought light and doesn't get hot

But what fun is that :D

P.S. They work in Maglite's too! (gotta get the right voltages)

Nice, a bunch of dropins:D


I believe I found your driver


whole bunch of those drivers


Some cameras like the one I have (Sony DSC-W30) only has auto-exposure. The only thing I can do is adjust the brightness using an art program.

I think I got it. It is now dark out side so there is no light coming in thru the windows. I have 4 pictures, first the control shot with nothing but the ambient light in the room. All 4 of these shots are under exposed and are actually brighter in real life. This to show relative brightness.

If you reduce the width of the browser window, it is possible to view all three lights at the same time.

The control shot.

Now this next shot is the original incandescent

next is the 8 Nichia bulb, the brightest of the 3.

and lastly the triple emitter bulb that can be purchased almost anywhere on EBay and Amazon for around $3.

I was in Lowes yesterday and got 2 of these on clearance.

Same as the other 2, it falls right in place. It has the driver in it so it runs on 12-24V no problem.

I also converted an old Ridgid light that I had that also uses 18V Li-ion batteries.
This light was a little more difficult as I had to cut a 49mm hole in the lens and glue the MR16 to the lens. The insides of the light were a little more sophisticated, it had it’s own 18V to 12V board so that the stock incan ran on 12V
This light took a little longer, not 10 minutes, more like 45. The stock bulb drew 0.90A. The LED is brighter and draws 0.20A
I know this type of bulb is advertised as 3W but in reality it is more like 2W.

My Harbor Freight drill light mod: https://budgetlightforum.com/t/-/19995

I have another one that might get an MR-16 …

I have a 4th Ryobi to mod. Once again I will use a 12-24V MR16 bulb and even though this Ryobi is only 9.6V, I will drive the LED’s to full brightness with the 9.6V. Anyone care to guess how it will be done?

Hint, it’s easy, and cheap.

$0.99 Chinese boost converter? http://www.ebay.com/itm/DC-DC-2A-Adjustable-Boost-Power-Supply-Converter-Step-Up-Module-2-24v-Input-New-/161650445447?hash=item25a31e0c87:g:9wAAAOSwrklVG4SM

Yep, that is easy and cheap!

Went ahead and did your mod on my old Ryobi FL1800 18V Worklight using the Echosmart 6w/35w Bright White Dimmable MR16 Bulb (P/N 1001401210 on packaging) from Home Depot. They also just reduced the closeout price from $4.33 to $3.53.

Hooked the bulb up to a freshly charged One+ Li-ion 18v Battery and let it run for not quite 5 minutes and don't think heat will be a issue. I removed the old incandescent bulb holder, test-fit the new MR16 bulb and had to take my Dremel tool and remove some material from the light head in the spot where the old incandescent bulb mounted to allow the MR16 bulb to sit flush. Soldered the wires to the new bulb then reassembled the light, using some 100% Silicone caulk to glue the bulb in place.

Light output is probably at least 3-4 times greater vs the old incandescent bulb, is much brighter/whiter and has a nice flood pattern that illuminates a good-sized area out to at least 50 feet. While I haven't tested runtime, even if it is a bit less, I feel the mod has totally transformed a formerly feeble light into a vastly more useful lighting tool.

OP - Thanks for creating this thread and for your helpful replies to my PM's.

Link to Home Depot MR16 Bulb - my local store had them on a Closeout Endcap Display for $3.53 each. http://www.homedepot.com/p/EcoSmart-35W-Equivalent-Bright-White-3000K-MR16-LED-Flood-Light-Bulb-ECS-16-35WE-WW-FL-FS1-BL/206127761?keyword=ecosmart+1001401210