Whether your camping, hiking, biking or thousands of other outdoor activities chances are there is going to be a time when your phone or other device like an action camera, tablet or even your USB powered flashlight is dying and your miles or even hundreds of miles from the nearest power source. Well this instructable will show you how I made this 12v backup battery for under $10.
This is a video showing a simple DIY 12v battery backup/ emergency power solution I made using 6v lantern batteries. There are just a few parts to make this work, please note that the batteries I used are of a temporary nature and a more permanent 12v solution could be found by using the rechargeables found in emergency lighting and exit signs from your local box store or hardware.
Step 1: Collect Parts
Now obviously I made my battery very simplistic, only the parts and connections I needed for my personal use, many modifications could be made.
I used 6v Lantern Batteries, due to ease of use, but any batteries would work, proper voltage of 12v is required.
2. 12v switch
My switch was an old broken led switch I had laying around but yours can be different.
3. 12v DC Cigarette Lighter type adapter
Can be found at almost any store with a hardware/ automotive department Box stores or Walmart where I live.
4. Wire, Solder and a Soldering Iron.
5. Containment Box
In my system water resistance was necessary but it didn't need to be water proof.
Step 2: And Begin!..
If you have a multi meter or volt meter the first step I would do is to check your battery voltage and ensure that your batteries are in good working order. Now if you are using two 6v lantern batteries, soldering them together will be our next step. (Skip this if you already have a 12v battery to work from) You want to solder one positive and one negative terminal from opposite 6v batteries together. This will be the basis for your 12v battery, I have my batteries bound together with tape so they wont wiggle around and break the solder.
You now have one 12v battery, from now on the posts that are soldered together will no longer be used. The opposite posts are the ones we will need and they should be a positive and a negative. Using these posts will grant you 12v.
Step 3: Wiring
Now this step fully depends on your switch, My switch had 2 connections 1 constant power connection coming directly from the positive on my 12v battery system, and 1 switched power connection which will be wired to the 12v DC Cigarette type adapter. The difference in these two connections is that the constant power is as it sounds, the constant. The switched power connection will only be receiving power when the switch is flipped to its on position.
So as stated above, assuming your switch is like mine, wire from the positive + port of your battery to the constant power connector on your switch, when soldering this make sure to keep the connections separate and use caution if your switch is plastic as plastic can melt as you solder, breaking your switch. The second connector, the switched power, will be wired to the positive + or in my case the red wire on the 12v DC adapter. Now from your negative - or in my case the black wire on the 12v DC adapter you will wire to the negative on the battery pack.
After all of your connections are soldered and covered your DIY 12v Battery Backup is complete.
Step 4: Test!
I used a USB car charger to test my battery and make sure it works. Its highly recommended that you use a multi meter if your unsure of your connections before plugging any devices into the battery. If everything is working use silicone or hot glue to seal all holes and make sure you cover exposed connections with tape or similar.
Your All Done!
Thanks so much for taking the time to follow my post.
Questions about this build can be sent to firstname.lastname@example.org and I will respond as soon as possible.