Modern action cameras are a useful tool for a photographer in that they are compact, robust and weather resistant. However, adventurous users quickly find that battery life isn’t their strongest point. For longer recording durations, such as time-lapse photography, a mains supply or USB battery pack is needed. Connecting an external power supply typically means opening a sealing door which nullifies the camera’s weather resistance.
This article explains the commercial solutions for using a power supply outdoors and also shows step-by-step how to make a custom-fitting water-resistant connector. Additionally, it shows how to make a weather-resistant USB battery pack housing to provide flexibility for powering an action camera.
To safely power an action camera outside a measure of weather resistance is needed rather than true waterproofing. It should withstand rain or heavy dew, rather than immersion in water. For example, I might put my camera out for the entire night when there’s the prospect of a clear sky to capture star trails, recovering it just before breakfast.
To use an external power supply but maintain a watertight seal there are commercial solutions, DIY modifications to commercial products and fully DIY solutions.
The simplest place to start is to check for a readily available solution. For example, GoPro sells a ‘USB Pass-Through Door‘ for their Hero 9 and Hero 10 models. It’s simply a replacement door with a soft rubber seal that fits around the metal shaft of a USB-C plug and is relatively cheap but effective. 3BR Powersports sell a range of cages, clamps and connectors for GoPro cameras.
If you’re looking to protect a USB charger outdoors, try the waterproof containers sold for outside Christmas decorations or garden/pond electrical connections. USB power banks marketed as ‘waterproof’ typically have a rubber sealing flap over the USB ports. They are water-resistant when stored but not when in use.
Modifying a commercial product
Slightly more complicated is to look to modify a diving housing or extended battery housing. For my GoPro Hero 6, I used a housing for a larger battery, put the battery aside and used the extra space to fit a cable gland. I had to cut the cable and resolder the connections as the plug wouldn’t fit through the hole. A search should confirm what housings or replacement doors are available for your camera model that might be adapted.
DIY waterproof USB connector
Lastly, with some thought you should be able to make a custom connector. Each camera manufacturer does something different; the example below illustrated is for the Insta360 ONE RS as this was particularly a challenge. The ONE RS is a modular camera and relies on being clamped together in its mounting bracket to ensure the seals between components are watertight. The USB-C power connector is under a small latching door. You should be able to adapt the method shown here to suit other models of camera.
In this design, a small plastic piece is clamped inside a lightly modified mounting frame. A silicone seal is fashioned that seals and secures a USB-C cable plug to the camera connections bay. The modified mounting frame can also be used in its normal fashion without the plug assembly.
- Silicone sealant. I use a white mould-resistant bathroom type (Dow 785+).
- Silicone release agent. I use petroleum jelly (Vaseline), but many oily substances work.
- Thin sticky tape, such as Sellotape.
- Thick sticky tape, such as cloth tape (for example, duct tape). Grey/silver tape is shown in the photos.
- Small piece of plastic, 20mm by 30mm, 3mm to 6mm thick.
- USB cable suitable for your camera. A smooth surface will give a better seal than a braid-covered cable. Unless you have a specific need, use a cable of 2m to 3m (6ft to 10ft) in length.
- Tools: While you’ll need tools to cut, shape and drill the plastic pad, a good set of needle files will make life easier. Scissors, tweezers, sharp-pointed knife.
Step 1: Remove the SD card/USB door. The retaining stalk pulls out with a gentle tug. Note the small rubber ridge on the back of the door that seals around the edge of the inside face of the connections bay opening. Eject any Micro-SD card.
Step 2: Cut the plastic piece so that it is just larger across than the hole in the side of the mounting bracket and twice its thickness longer than the hole.
Step 3: File the short ends of the plastic piece at about 60°. File the upper and lower ends of the hole in the mounting bracket to match. You want the plastic piece to fit snugly inside the mounting bracket hole so that it is trapped by the bracket when assembled. You will probably want to round off the corners on the plastic piece but leave the vertical sides of the bracket to maintain its strength. Continue filing until the plastic piece is recessed about 1mm into the bracket.
Step 4: Drill through the plastic piece over the USB connector and enlarge the hole so that the plug will connect. File the plastic shroud on the USB plug to give a textured surface; this makes the silicone rubber grip better. You will need a gap of about 3mm all around the plug.
Step 5: Clean the side of the camera and the surfaces inside the connections bay. Using the thinnest sticky tape you have, cut small bits to seal over both side recesses where the door latches. Tweezers are useful here. Cut another small bit to go over the microphone hole.
Step 6: Build a few layers of thick tape to about 1mm depth, then cut and fit inside the base of the connections bay. Leave 1mm around the periphery and round the corners – you need to leave bare where the door would otherwise seal (as noted in step 1). Press down firmly to ensure the tape seals over the SD card and USB port orifices.
Step 7: With a sharp-pointed knife, cut the tape pad for a tight fit when the USB plug connects. Be careful not to damage the connector.
Step 8: Clean the side of the camera, inside the connections bay, the plastic piece and the USB-C plug to remove any oils. Build a few layers of thick tape to about 1mm depth and apply to the inner surface of the plastic piece or camera side about 2mm beyond the edge of the connections bay.
Step 9: Check everything fits together. The mounting bracket might not fasten depending on the thickness of the tape used in the last step.
Step 10: Using a cotton bud or similar, apply a thin layer of your release agent to all the surfaces in the connections bay and the side of the camera. If the amount of silicone you use in the next step is too generous, the excess silicone will ooze out over the camera, so apply plenty – particularly to the rubber surfaces as silicone bonds to these. Ensure the sealing surface at the edge of the connections bay base is smooth. Apply some release agent inside the mounting bracket around the side hole. This makes it easier to get apart after the silicone has cured.
Step 11: Connect the USB plug then squirt silicone into the connections bay, ensuring there are no voids in the corners or behind the plug. Press the plastic piece inside the mounting bracket down over the camera. If silicone doesn’t ooze up around the plug body, squirt some more into the gap. With a wet finger, smooth the silicone into a skirt around the plug body.
Step 12: Leave the silicone to cure. This may take several days. Manufacturers of silicone typically quote curing time in terms of depth, such as 3mm per day.
Step 13: Once cured, gently wiggle the mounting bracket off. Gently ease out the plastic pad and cable, pulling both at the same time. Trim off any excess silicone with a sharp knife, leaving a small skirt around the connections bay lip. Remove the tape pads including the thin bits over the door latch recesses.
Step 14: The mounting bracket should now clamp shut squeezing the newly formed cable/plug assembly for a watertight seal. The assembly will come out through the side hole in the mounting bracket with a little wiggling. If you’re dropping the cable in your photography bag, use a small zip-lock bag over the end to protect the sealing surface.
Battery removal. When powered from an external supply some action cameras, like late GoPro Hero versions, need the internal battery removed. Otherwise, the internal battery is used first and then the camera shuts down regardless of an external power source. Other cameras will use external power first and charge the battery in the process. Check how your camera operates.
DIY waterproof USB battery case
This adapts a plastic case to allow a USB cable through a watertight seal. The steps below show how to fabricate silicone rubber pads that allow a USB battery pack to be sealed inside and removed for recharging.
I use ‘Plastic Protective Hard Case‘ as this is reasonably light, robust and sufficient to hold either my 10,000mAh USB battery bank or my 20,000mAh pack. When sizing your box/case, allow some additional space inside for the seal and the body of the USB connector. I use a right-angle USB adaptor for my 20,000mAh pack as the connection is on the side.
A 10,000mAh battery is sufficient to power most action cameras overnight. You will need to size your box according to your needs.
- See the DIY camera connector notes above, particularly a smooth finish cable.
- Plastic pieces for formers. I’ve used bits of chromed plastic trim and bits of plastic channel conduit.
- Bolt/screw/tube/rod of slightly smaller diameter than your cable.
- A small block of wood or foam.
- Glue to fasten plastic.
- Rubber band or small weight.
- Tools: You’ll need tools to cut, shape and drill the plastic formers, and a round needle file.
Step 1: Determine where your cable should optimally enter the case. Ideally, this should be through a straight rather than curved part of the case wall.
Step 2: Carefully remove the rubber seal from the case so it doesn’t get damaged while filing. Remove the foam pieces. Put them somewhere safe.
Step 3: Shape plastic pieces to hold the silicone seals. This will be at least 20mm long and 20mm wide and the depth of the lid and base. Don’t worry about small gaps.
Step 4: Glue the plastic pieces in place. Leave to let the glue set. Once set, ensure the case closes. You can check how closely the base and lid formers match by squashing a blob of blu tack between them; it’s not important for an exact fit.
Step 5: On the base, carefully file a half-round just big enough to lay in the cable, in both the outer case wall and the inner plastic former.
Step 6: On the lid, carefully file the remaining cable passage. You can turn the case over and close the case lid around the file to start filing in the corresponding location. Ideally, the case’s rubber seal (when restored) will press on the cable when the case is closed – there may be a deeper cut on the base or lid to achieve this.
Step 7: Find a bolt, screw, tube or rod with a smooth surface and slightly smaller diameter than your cable. How much smaller will determine how tightly the cable is gripped when the case is closed. The smooth part should be long enough to lay between the case wall and the former.
Step 8: Find a thumbnail size bit of material (plastic/card/metal) about 1mm thick. This is used when making the second sealing pad. Its thickness determines how much squashing force is needed to close the case.
Step 9: Shape a small block of wood or foam to go over the bolt/screw/rod while it’s resting between the case wall and the former. If it hasn’t got a smooth surface, cover it with some tape.
Step 10: Clean the areas inside the formers and the corresponding case wall to remove any surface oils. If there are any gaps between the edges of the formers and the case wall, seal them with either tape or a blob of Blu tack.
Step 11: Smear a thin even film of release agent on the shaft of the bolt/screw/rod (from step 7) and on the block (from step 9).
Step 12: Squirt silicone into the former in the base ensuring there are no voids in the corners. Fill it up so the silicone is flush with the lip. Apply the block (from step 9) and hold it in place with a rubber band or small weight.
Step 13: Leave the silicone to cure. This may take several days. Manufacturers of silicone typically quote curing time in terms of depth, such as 3mm per day.
Step 14: Once fully cured, the block and bolt/screw/rod should peel readily. Trim any excess silicone with a sharp knife.
Step 15: Smear a thin film of release agent on the base silicone pad. Coat the shaft of the bolt/screw/rod (again) and replace in the groove in the base pad. Ensure the release agent on the shaft and pad is smooth.
Step 16: Squirt silicone into the former in the lid ensuring there are no voids in the corners. Fill it up so the silicone is just over the lip. Using the ~1mm material from step 8, trap this between the lips as you close the lid so that the lid is prevented from closing fully. Hold the lid in place with a rubber band or small weight.
Step 17: Leave the silicone to cure. This will take several further days.
Step 18: Open the case, being gentle when separating the silicone pads. Remove the bolt/screw/rod and trim any excess silicone with a sharp knife.
Step 19: Carefully cut the foam inserts to fit around the formers and replace in the base and lid. The foam has the advantage of keeping a battery pack warm when the case is left out somewhere cold which aids its efficiency. The foam inserts can be removed when deployed in a warm environment.
Step 20: Check the lid secures correctly when a cable is laid in the seal and the cable is gripped snugly.
From my garden alone, using an externally powered action camera I’ve captured all-day and all-night timelapse videos, all-night star trails and even snapped the Milky Way arching across the sky.
About the Author
David Hancocks is a photographer living in northwest England. He’s been tinkering with housings and frames for cameras in challenging places since the 1970s.