Introduction: Rechargeable LED Mason Jar Portable Lamp – Perfect for Cabin/Camping/Small Room/SHTF
Do you have an off-grid cabin, like to go camping, or just want something that puts out decent lightening if SHTF that's easy to maintain and portable? How about a closet or laundry room that needs some supplemental lighting? If the answer is yes to any of these, this project is for you!
Did you know that LED's typically last about 20 years under 4 hours of daily use? This is the ultimate SHTF lighting project!
I began designing this after receiving two electric bills that surpassed the $300 mark! We're on a tight budget (no doubt after those insane-o bills!) and decided to start looking at simple changes we can make in our lives right now. This fit the bill!
Materials That Will Be Used:
* 1 Qt. Wide Mouth Mason Jar. You can alternatively use any jar that you can get these components to fit into. Ideas include: pickle jars or 40 oz. peanut butter jars. I was initially going to use a standard 1 qt. Mason jar but the opening was not quiet big enough for the bulb; so be sure to look for a wide mouth jar. You can also often find mason jars at your local second hand shop for about a buck or less. Mason jars happen to be one of those things I've never seen sold less expensive online than what you can purchase them for at a "brick and mortar" store. Most grocery stores and department stores carry these at a reasonable price. Since I dabble in canning anyway I just purchased a case of 12 of these for $11.99 from my local hardware store. Total project cost: Free - $1.00
* 5v/5w USB LED light. I've found these on eBay for $1.49 each free shipping
* Scrap electrical wire - Ideas to look for this: old kids toys, broken electronics (such as DVD players), old USB cables you don't need, old broken headphones, etc. If you need to purchase wire I'd recommend 24 AWG electrical wire. It's thin enough for small electrical projects but hardy enough to make your projects good quality
* 18650 battery holder. I've found these on eBay for $2.83 free shipping for 10 - making the cost for this project: $0.28
* USB DC/DC 5v step-up module board. I've found these on eBay for $1.13 free shipping (make sure the one you order has a type A female USB connection)
* SPST switch (or SPDT switch) I had spdt switches on hand. I've found these on eBay for $1.97 free shipping for 10 - making the cost for this project: $0.20
* Micro USB battery charging module board I've found these on eBay for $0.75 free shipping
* 18650 rechargeable battery - I recommend a brand you trust
* Optional:Glass Frost
* Optional:Scrap wire (a cloths hanger would be perfect) We will be using this to create a "handle" to carry around our lamp or to hang it from
Total Project Cost:$3.85 - $4.85+ depending on how much you're able to scrap from around the house
Tools of the Trade That Will be Needed:
* Soldering wire
* Soldering iron
* Electrical tape
* Small file
* Hot glue gun (if you will be leaving this in the sun to recharge or storing it in a location that gets warm I would recommend substituting the hot glue with E6000 – since I will be charging this with my solar panel 18650 battery charger I will be using E6000)
* Optional:Helping Hands would be useful, but not necessary
Step 1: Optional: Frost Your Jar
I've tested out this light bulb and the light is very harsh if your eyes wonder close to the bulb when turned on. I've decided to frost the outside of my jar. This will also serve to hide some of the wiring inside (although being able to see the wiring would be pretty cool too!)
Follow the package instructions for your glass frost and do this in a well ventilated area (outside would be ideal).
Step 2: Prepare Your Lid
We don't want to take this lid off all the time to turn this on/off or to charge it. So we'll be creating two holes in the lid. One for the Micro USB port from your charge board to fit through and the other for your switch (which will turn the light on or off) to fit through.
But don't forget we'll also be hanging the light from the inside of the lid as well. Think about how you'd like to hang the bulb from the inside of the lid. I ultimately decided to glue a piece of string with E6000 to the center underside of the lid (as shown in the first image) to tie the bulb in place. This will allow me to easily remove it if I decide to re-purpose the light down the road.
Knowing that my string would be taking up the center space of my lid I decided to put the hole for my on/off switch and the hole for my Micro USB port on each side of where I glued the string.
I marked on the lid where to cut. For my toggle switch I found that a 3/16th size drill bit was the perfect size. I then used a 7/16th drill bit to make holes at each side for the Micro USB port as seen in the second image (I don't have a dremel... not sure if that would have been a better option). I used a knife to then make the hole bigger. It fits (see the third image) but it doesn't look very great. In hindsight I should have been more patient and used a file to complete the Micro USB hole (I also pushed too hard with my drill and made an indent... this metal is actually quiet soft). I will know better the next time I make one of these.
Step 3: Connect the Negative Wires
For those interested I have provided a basic schematic for this project in the first image.
I decided that I would keep the battery holder at the bottom of the jar instead of trying to make it fit to the underside of the lid. Either way you decide to design this think about how long you'll need your wires. Remember that the switch and Micro USB charge board will be on the lid of the jar. The DC/DC step-up module can be placed wherever you'd like. I kept that at the bottom of the jar as well.
Note: I decided to be be picky and painted the outside of my battery connector with white acrylic paint so that it would blend in with the jar a little bit better. A totally unnecessary step. In addition I had a DC/DC step-up module board laying around the house that would work just fine so mine looks different than the one I linked for the materials for this project.
Solder two wires to the ground (negative) of your battery connector.
Solder one of these ground wires to the ground of your DC/DC step-up module board.
Solder the remaining ground wire to the ground of your your Micro USB Charge Board as shown in the second image.
Step 4: Connect the Positive Wires
Solder two wires to the positive side of your battery connector.
Solder one of these wires to the positive terminal of your Micro USB Charge Board.
Solder the remaining positive wire from your battery to one of the outer pins of your switch (if you purchased a STDT switch it doesn't matter which one) as shown in the first image.
Next solder a wire to the positive terminal of your DC/DC step-up module board.
Solder the other end of the positive wire coming from your DC/DC step-up module board to the center pin of your switch as shown in the second image.
Step 5: Prevent Short Circuits
Cover all areas with exposed wires with electrical tape to prevent short circuits. We want to light a room, not set a room on fire!
Step 6: Test Drive Your LED Light
We're going to make sure everything is working okay before we start making anything permanent.
What I like to do is put a piece of string over the center of my battery holder before I put the battery in to create a very quick way for me to remove the battery without risking getting burned if anything goes wrong. I highly recommend you do this for your own safety. Put your battery into the battery holder. Nothing starting to smoke? Good! Now plug your USB light bulb into the DC/DC Step-Up Module. Did the bulb turn on and still nothing is starting to smoke? Great! Now put your switch into the "OFF" position. Did your light turn off and still no smoke? Fantastic!
Now unplug your light bulb. Next we'll test our Micro USB port. Let's start by looking it over and making absolutely certain we have the wires positive to positive and ground to ground. Next, let's check the charge of our battery. Ideally it will need at least a little charging. Check the voltage of your battery with your multimeter. Make note of the number. Replace your battery in the battery holder. Plug your Micro USB charge board into whatever charging device you will be using (I used a wall charger in the above image). Wait a few minutes and recheck the charge of your battery with your multimeter. If the number has gone up (and again we haven't made anything smoke or start on fire!) our wiring has been successful!
Unplug your battery and move on to the next step!
Step 7: Attach Your Switch & Micro USB to the Lid
Since my switch had a nut that screws it on tightly I did not glue it down to the lid. But I did use glue on the back side of the Micro USB charge board to anchor it in place as shown in the above image.
Step 8: Put All of Your Components Inside Your Jar
There was a lot of extra wire length on the LED light bulb. I just tightly wound this up around the upper part of the bulb and anchored it with a rubberband as seen in the first image. I may want this length later if I decide to re-purpose the light. I tied the hanging section that came with the light to the string and put my battery back in the battery holder and gently put everything inside the jar and... done!
I now have a cool looking light that can be charged from my solar panel battery charger wherever I go, even if the electrical grid goes down! And hey, I can charge it from the wall too if I want!
Step 9: Final Thoughts
How Well Does This Light A Room?
I took this LED Mason Jar Lamp into my laundry room which has no windows and a door that I closed making it pitch black. I turned on the light. The first image is how well this lamp lit up the room. Is it as bright as what you're used to with more conventional bulbs? Not really. But honestly it puts out an amazing amount of light when you consider it's power consumption. It's certainly enough to be perfectly satisfactory for any of the situations I've mentioned in my opinion.
Easy Off-Grid Lighting Solution
The second image is me charging this lamp with my 18650 solar panel battery charger. Using a solar charger like this truly makes this an off-grid option. There are many portable solar chargers out there that are relatively inexpensive that would be a perfect fit for this lamp. Look for anything that's designed to charge 5 volt devices such as cell phones and tablets.
Won't The Bulb Break Inside The Jar?
The light bulb itself is made 100% out of plastic so there is no need to worry that it will break inside of the jar. I've also left the light bulb on for an extended period of time and the bulb does not get hot, just a little warm to the touch. In addition you could make this "drop proof" by using a 40 oz. wide mouth peanut butter jar made of plastic. You'd pretty much be guaranteed that this lamp would never break even if it's being handled roughly.
So... How Long Will The Light Last?
This really depends on the mAh rating of your battery. In a nutshell the higher the mAh rating the longer it will keep this bulb lit. I tested out how long this light will stay lit with a 2500 mAh battery (not super high in terms of modern rechargeable batteries). When I turned the light on the battery was at 4.20 volts. 2 hours and 5 minutes later the bulb began to flicker. The battery was drained to 3.28 volts. Certainly a person could use a battery with a higher mAh rating and get more time out of this lamp. Optionally you could wire a second battery in parallel to double the mAh rating or even design something using different batteries all together.
Hanging This Close To The Ceiling Would Be Best For Maximum Lighting
Finally, you can make a handle for this lamp so that you can hang it or carry it around by following the simple instructions in this video: How To Hang Mason Jar
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