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.

34 thoughts on “A Vacuum Battery Made For Looks And Learning

  1. This is the second time this week that I read “vacuum something” in a headline and I wonder how they do that with vacuum. Like, how much energy can we get from a canister at 1 atm differential? Wouldn’t it be better to use positive pressure, like pellet guns? How to regulate it?

    1. looks like you didn’t bother to read the article in the slightest. vacuum battery as in an electric battery for a vacuum cleaner nothing do do with evacuated canisters here.

      1. Looks like you didn’t bother to read the comment in the slightest, he was talking about what the headline made him think, not the body of the article. I thought the same thing. Vacuum battery, as a concept, kind of evokes that idea.

        Next time, assume the best, instead of pouncing.

          1. This vacuum cleaner battery seems like a waste of battery runtime, but it is pretty from an artistic perspective.
            Side note, my brain is now trying to think of ways to make a battery powered by a vacuum.
            Personally I would have thought a battery powered by an evacuated cylinder would be an awesome concept if it could be made viable.

    2. Why not store thousands of gallons of ice in vacuum insulation? With peltier generators I think you can get a Wh per Kg(At absolutely horrible sub-percent cycle efficiency).

      But the side effect if discharge us to generate cold, and charging generates heat with totally perfect efficiency, and the whole process also results in a chilled and therefore preserved emergency water supply.

      Combine it with your water heater to capture the waste heat, and use it for air conditioning, and you might have useful amounts of energy stored by the time you hoard enough water to completely cover air conditioning and refrigeration needs.

      If solar gets *really* cheap and you can have 10KW of it, 1% efficiency seems totally acceptable when it also covers your AC as well.

          1. On a happier note, I discovered that silver polish will do electroless plating on copper. Dude who sold it say the idea never occurred. Same valance.

          2. https://www.tifoo.de/

            In case it helps anyone else, I got some conductive copper varnish from here (spent time messing trying to make graphite paint, didn’t work) for coating organic stuff for pre-plating (use normal varnish first) – they also sell (safe) bath plating solution for silver and gold.

  2. The battery is gorgeous, and the workmanship talented. But for some reason the thing I fixated on was his mechanical spot welder. Digging through his channel, there’s a Russian-only video about the machine. The translation is clearly struggling at times but it’s pretty interesting. Worth a watch on it’s own, and I’d love it if someone who spoke Russian made a go of translating the interesting details.


    I do love how he dials in the pulse size needed – test welding on a dead battery. The first shot blows a hole in the end, so he just turns the motor speed up (and pulse length down) until the welds not only leave the battery intact – he keeps going until they don’t produce excessive welding.

    And if I caught the backstory right, the machine was purchased to refurbish for his wife’s stationary business – he’s just borrowed it to spot weld this battery together.

    1. Have you seen the spot welder video on YouTube by Dan Gelbert? He’s got a pretty neat homemade unit. Not so much in his video about how it was built, but he does go over it

  3. Ok, so was the first one, shown at 2:30, a bust? So he had to make another one using paint as etch resist? Otherwise he etched two cylinders, so where’s the other one?

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