Hand Held Video Light, Battery Powered, Camera Quality, High CRI

I am into photography and when I saw the concept called light painting, I wanted to give it a try. This is why I have built this handheld light to shoot outside. My objectives are;

to have it small enough to carry around in a bag,

to have it battery powered yet bright enough to fill the object with light,

to have it run longer than an hour.

LG INR18650MH1 3200mAh 10A Lithium-ion Batteries x3

You can supply them from your local seller. I preferred them because they are the best value for the price and the most capacity that I can get for the price. You are free to change them according to your needs.

3S 40A BMS to protect the batteries

I recommend 40 A balanced protection board. I tried 20 A at first, but it was not powerful enough. You can move forward without using any, but I highly suggest using one.

120W 8A Voltage Regulator to achieve the same brightness always

This is the exact model I'm using in the light. It is more powerful than needed but you know what they say "Better safe than sorry". You can choose anything that can fit in the light. It has to be a buck boost converter though since the fully charged batteries are higher than 12 V and fully depleted batteries are lower than 12 V.

3S 2A Type-C Battery Charger to be able to use your light again :)

Even though batteries can handle to be charged faster than that, the faster charger gets very, very hot. Since there is no heat transfer possible for the charger, get the one with 2A inputs current. It'll just take a while to charge it.

Battery Capacity Indicator to be able to plan ahead during the shoot

I love being able to see how much juice left and I think these modules are the best to do it.

LED Dimmer 10kHz PWM to adjust the brightness without any noticeable flicker for the camera

Flicker is a big issue for a video shoot. I wanted to be able to use them for my videos as well. That's why I get a high frequency dimmer. And the best part is that these dimmers are also on/off switches. So when you turn them down all the way, it'll click and cut power.

CRI95 LEDs to get the best colors from your shoots

You only need 80 cm of LED strip. I had them laying around left over from another project. This is why I utilized them. You can use any color temperature or any CRI rating. It is just the more CRI, the better for a camera shoot.

PLA 3D Printing Filament to print the body

The prints will take less than a 200g of material. I use PLA because it is stiff and I know how the material behaves while printing.

5 mm Aluminum (or any other metal) to use as a heatsink and backplate

LEDs are getting hot and when they do too much, they burn! I used an aluminum backplate to both act as a heatsink and a structural component.

Like I said, there were exactly 80 centimeters of these LEDs laying around at my workshop. I thought this is the perfect chance to use them. I have tried a couple of patterns to put all the LEDs together, and I landed on this. Cut the strip from each segment. It should have 1 cm thickness and 5 cm length and there should be 16 of them. I suggest sticking them with tape to a flat surface for soldering. Get 2x 30 cm of cables. Peel off 16 cm of the insulator from one side for each cable. One cable will be positive, and the other will be negative. Start from the side with the insulator and work your way up. Solder every positive connection to one cable putting heat shrink between each connection to prevent the cable touching to the opposite polarity. Do the opposite for the other side. You will have parallel connection for each segment. You can light this LED panel up by supplying them 12 V.

(Do not mind the cable passing by on the photos! It is there because there was a broken connection, so I jumped a cable from the other side.)

You can find the schematic for electronics but to make it easier to understand, I will subdivide the electronics.

Power

I am using battery holder in series to avoid soldering batteries together which can damage them. I suggest you to do the same since the interior of the model is designed according to it. Here is the schematic for how to connect a BMS to batteries. Normally, this module is designed to be attached right over batteries. But we are going to put it in another section in the model. That's why to prevent a further problem, try to orient them is I did. The best way to do it is to put a divider onto the batteries and get the cables reach from one side.

This section contains battery indicator and the charger as well. These are very straightforward. Connect the charger to the power output of the BMS. It'll be the same for the indicator with one difference which is a button in one of the cables. We don't want the indicator to be lighted up all the time. I used a small breadboard button and integrated an interface to the model.

Voltage Regulation

Is mentioned before, it is best we use a buck boost converter to get a stable 12 V output. This ensures that the brightness of the LEDs will stay stationary. The connection of this module is as easy as it can get. Connect the positive output of the BMS to the positive input of the buck-boost converter. The same for the negative. Now we have 12 Volts all the time without having to worry about how much juice left on batteries.

LED Dimming

Its connection is very easy too. Positive output from the converter to the positive input of the dimmer. Negative to negative as well. However, since that was lack of empty places in the electronics compartment of the model, I needed to separate the rotational component of the module from the module itself. Only this way, I could have an easy operation of the dimming process. Just desolder the pins from the board and connect them with cables. This could be harder than you think if you have never done it before. So, take your time and be careful!

The constrains for the design are to be able to hold it with one hand, easy assembly and also my favorite "Goooood looking" :)

I am much more confident designing for 3D printing than any other processes. I have designed mostly for 3D printing for that reason. However, there was need for other methods like laser cut plexi-glass and aluminum cutting and drilling.

3D Printing

I tried to avoid supports for 3D printing as much as I can but there are places in which using supports makes much more sence then avoiding supports with another technique. There is need for support in the electronics compartment part and LED holding part. Others can be printed without any support at all. There are photos for how to place them on the print bed.

Aluminum Cutting and Drilling

I'm using 2x aluminum side by side which are 30 mm x 5 mm x 261 mm. The reason that I'm using these is because I have the material and did not wanted to purchase another one. You can use whatever you have to use as a back plate. Using metal is suggested since these LEDs are getting hot, however, printing them would work either. Just try not to let them heat up that much. The locations to drill on the aluminum given with a PDF file to print out on a paper and use as a template.

Plexi-Glass Cutting

This is a cut that you can do with hand tools or woodworking tools if you have. But I prefer to make it by laser cut. Here's a vector file for that.

First of all, let's attach the LEDs. To do that, place the aluminum block on the back of the 3D printed LED section. Use the cable openings on the printed part to align LEDs, and stick them to the aluminum. Now we have to put the plexiglass. Remove the aluminum along with LEDs, put the plexiglass in and place the aluminum again. The inside can be covered with aluminum tape to bounce more light and prevent PLA to show the light. If you want that, do it before putting plexi and aluminum back. The only part to be glued can be attached now permanently. I used CA glue which works perfectly on PLA. Place one or two drops onto each fingers touching side and attach them permanently. Don't worry! The aluminum block still can be removed. Once you get the cables of LEDs to the other side of the aluminum with the holes right next to them, this assembly will be finished and set aside for now.

Now, it's time to place batteries. The battery holder should fit easily into the battery compartment of the model. I used hot glue to attach the holder to the PLA but double sided tape would work just as fine. In this part of the model, there is also a hole for tripod mount. I used square nuts for the purpose. It would work the best if you can find them. Regular nuts could be embedded with some help of a glue or something.

These two assemblies are designed to slides onto each other and screwed from the side. Do that, and we are halfway there.

The BMS now should be attached with double-sided tape making sure that it's not going to touch to the aluminum.

The last thing before closing it up is to put the electronics in. Most of the electronics have specified places on the model. I would like to start with the battery indicator. Put it in and glue it up with hot glue. After that the button can be placed after soldering two cables to its legs and again hot glued. The battery charger, the voltage regulator, and the dimmer are just the same. Use hot glue to attach them to their places as seen in photos. Rotational part of the dimmer is going to be screwed from the outside. The nut to do that comes within the package.

After soldering and connecting all of the cables according to the schematic, it is time to screw the electronics compartment.

That's all to do! Please do enjoy your light!