A Vacuum Battery Made For Looks And Learning

Looks and RGB LEDs are usually not a priority in tool batteries, but [Oleg Pevtsov] decided the battery for his DIY vacuum cleaner needed to be different. In the process, he learned some lessons in chemical etching, plating, machining, casting, and electronics. See the video after the break for the build compilation.

The core of the battery is just five 18650 cells in a 3D-printed holder with a BMS, but the real magic is in the external components. The outer body is a brass tube with the logo etched through the 0.6 mm wall. Getting the etching right took a few tries and a lot of frustration, but he eventually found success with a solution of sulfuric acid and nitric acid in a magnetically stirred container. For etch resist he sprayed lacquer on the outside and filled the inside with silicone. The inside was then coated with clear epoxy by allowing it to cure while spinning. The final touches were nickel plating, then gold plating, and a high polish.

The silver-plated connector on one end consists of a machined copper tip and ring, epoxied together for isolation. The tip has a multi-start external thread, allowing the female side of the connector to securely connect with a single twist. A set of RGB LEDs were added to the core to light up the battery from the inside. We have to hope the vacuum this is supposed to attach to is equally impressive.

This being Hackaday, we see a lot of custom power banks for all the custom electronics. These range from a small power bank for on-the-go soldering to a heavy metal beast with a built-in inverter.

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A Hot-Swappable Battery Grip Keeps The Camera Rolling

There’s nothing worse than being in the middle of an important shot, only to have the camera’s batteries die on you. The losses can be very real, so it’s best to avoid them entirely. In an effort to do so, [funkster] built himself a battery grip for his Canon EOS M.

The hack is based around the venerable 18650 battery, packing 3.6V of lithium-ion goodness into a compact metal can. [funkster]’s build has slots for two of these cells, powering the camera off of one and keeping the other in reserve. The cells are monitored by a STM32 microcontroller, which switches from one battery to another as they run out or are removed. This allows batteries to be swapped while the camera is on – a highly useful feature. There’s even an OLED display to keep an eye on the state of charge of each cell.

The manner in which power is connected to the camera is rather amusing. An original Canon battery that slides inside the camera was gutted and turned into a simple adapter for the battery port. The battery grip, which wraps around the camera body, connects to this via pin headers that pass through a hole drilled in the camera’s case. It’s a permanent mod, but one [funkster] is happy with for the added usability – especially as doing it this way still provides easy access to the SD card slot.

Keeping a camera juiced on the go can be a headache without the right gear. [funkster] demonstrates that if you can’t buy it, you can always build it yourself. If your problem isn’t battery power, but your camera is overheating, you can of course fix that too. Video after the break.

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