It is no secret that the GoPro range of cameras has a very limited battery life. This becomes particularly apparent when trying to take long term time lapses. As such I built this external battery that will maintain the IP rating of the camera and the Peli case.
Please refer to manufacturers instructions with regards to ratings of components and how to properly fit them. Despite the components being IP rated, I would not personally submerge this in water.
Step 1: Write Out Steps, Parts List & Source Components
The first part of this project was working out what I wanted to get out of the end product. I was then able to work through the project and write a parts list. In conjunction to this I then wrote a step by step list to cover everything that I needed to do.
My parts list is as follows:
1 x Peli 1200 Case
1 x 12v 17ah Battery (Check that it will fit in your chosen Peli case)
1 x Set of Battery Fly Leads
1 x GoPro Extended Back Door
1 x Cable Gland
1 x GoPro Battery Eliminator
1 x 2 Pin Panel Mount Socket
1 x 2 Pin Plug
1 x 2 Pin Socket
1 x Piece of Scrap Wood
In addition to this I used various tools which included: Multimeter, Electric Drill, Spade Bits, Side Cutters, Saw Soldering Iron & Solder.
Step 2: Battery Holder
In order to stop the battery from moving around in the case I cut an L shape of wood. This stops it from moving left to right as well as rising up into the lid.
Step 3: Cable Gland Location
By using the skeleton extended back door I was able to put the battery eliminator into the camera and work out the best location for the cable gland to go. I could use this method to check that the cable coming out of the eliminator would not snag and that the lock nut on the cable gland would not catch.
Step 4: Fitting Cable Gland to Back Door
Once I had decided on the location of the cable gland I marked the location on the extended back door. I chose to make the hole through the label in order to reduce scratching and cracking of the plastic, to do this I used an appropriately sized spade bit. Once I had made the hole I removed the label and brushed off any excess plastic. I then put the cable gland through (with the rubber washer on the outside) and secured the lock nut to the inside.
Step 5: Fitting Socket to Side of Case
Once a location for the socket on the side of the case has been determined, mark it up and use a hole bit to make a hole. Fit the socket through the hole and secure the lock nut (making sure that the rubber washer is on the outside of the case). As ever follow the manufacturers instructions.
Step 6: Fit Battery Eliminator to Back Door
Fitting the battery eliminator to the back door is a simple case of cutting the plug off the end and passing the cable through the gland.
As the cable gland I used would not close small enough to properly clamp down onto the cable I put heatshrink on to the cable in order to increase its thickness. I then passed the cable through the gland, leaving enough slack on the inside to allow the back door to be opened with the battery eliminator still plugged into the GoPro. When closed this coil of cable helps to keep the GoPro pushed forward into the housing.
When cutting the cable I made the cut about 10cm from the plug, thus allows the plug to have a socket wired onto it (see later step). Once I had cut the cable I used a multimeter to check the voltage that was carried down the cable when it was plugged into a 12v supply. This particular battery eliminator carried 12v and drops the voltage down in the insert that goes into the camera. It is important to check this step as if the voltage drop down was to happen in the cigarette plug end, cutting the cable and putting 12v down it could potentially damage your camera.
Step 7: Fit Plug to Battery Eliminator
The method for fitting the plug will depend on the make and model that you use. With the Bulgin Buccaneer series of connectors that I have chosen, the pin must be soldered to the cable and then inserted into the plug/socket housing.
I stripped the cable according to the instructions, soldered it to the pins and then fitted the plug together. You will need to decide on a pin configuration to use in all the plugs and sockets. I used two pin connectors with pin one as positive and pin two as negative. Be sure to follow the instructions and assemble the plug in the right order.
Step 8: Cigarette Plug to Socket
In order to make the battery eliminator as useful as possible I fitted a socket to the end of the cigarette lighter plug (making sure to use the same pin configuration as on the plug fitted to the battery eliminator). This will allow me to run the camera in a vehicle without using the battery.
Step 9: Fit Fly Leads to Socket
After stripping the end of the fly leads and soldering them to the pins, they can be put into the socket on the side of the case (ensuring that the polarity is kept the same as the other connectors).
Step 10: Fit Battery
Connect the fly leads to the battery and place it in the case. Put the wooden L shape into place to stop the battery from moving.
Step 11: Check Everything Works
Now is the time to check that everything works and fits securely into the case for transport. I am currently in the process of running a long term test with my camera to see how long I can get out of the battery.
Step 12: Label Pin Configuration & Fit Socket Cover
In order to aid memory if subsequent modifications or repairs need to be made, I put a label on the inside of the lid that shows the pin configuration.
I also fitted the counterpart cover to the socket in order to maintain its IP68 rating when there is nothing plugged into it.
I plan to stick a GoPro mount to the outside of the case in order to hold the camera securely without the need for a tripod or other mounts.