DIY External Power Supply for BMPC 4K Camera Ⅱ

In the previous article, DIY External Power Supply for BMPC 4K Camera. However, due to space constraints, a battery level indicator wasn't included, leaving users unaware of how much power was used or remaining. The solution was to integrate the battery level display into the power cable, primarily using a USB power tester.

This tester supports an input voltage of 5 to 20V and can display voltage, current, time, and power consumption.

First, the casing was removed, and the USB plug and socket were detached. After soldering, the voltage was tested at around 12V, which worked fine, but light leakage was severe, making the surrounding area brighter than the text in the center.

To address this, a piece of masking tape was cut to fit the display area and applied, significantly reducing light leakage during power tests.

The XT30 socket's embedded design made it challenging to grip and unplug the connector, so a 3D-printed casing was created to extend the plug length, making it much easier to use. For the 5.5 power plug, the original casing was cut off, and a custom angled casing was printed to fit. The USB tester originally had large square holes for USB-A ports, which were also 3D-printed to accommodate the wiring.

After the connections were made, voltage, current, usage time, and power consumption were all clearly visible. The power supply can be placed in the camera bag and hung under the tripod as a counterweight, with the battery level display conveniently positioned next to the camera for easy viewing. When handheld shooting is necessary, the built-in battery can be used, providing nearly an hour of power—usually sufficient for most scenarios.

Finally, a photo was taken with the power supply, showing that the overall size of the setup is quite manageable.