This spinning water contraption is definitely a purposeful battery
— June 18th, 2025
If you happen to ask somebody to think about a battery, they’re in all probability going to image a chemical battery, like a AA alkaline or a chargeable lithium-ion battery. However there are other forms of batteries that retailer power with none fancy chemistry in any respect. If you happen to discover a option to save power for later, you’ve a helpful battery. Erik, of the Idea Crafted Creations YouTube channel, achieved that by storing kinetic power in a spinning flywheel weighted with water.
This isn’t a loopy concept, as a result of flywheels exist particularly to retailer kinetic power in a spinning mass. On this case, most of that mass comes from tubes stuffed with water. Water is cheaper than one thing like forged iron and it’s simple to regulate the degrees to keep up good stability.
However this moist flywheel has one other trick up its sleeve: adjustable second of inertia. Watch an ice skater as they tuck into spin and also you’ll perceive this. By pulling their legs and arms shut their axis of rotation, the skater can cut back their general second of inertia and enhance their pace. Erik’s flywheel can do the identical factor by actuating the cylinders of water to convey them in nearer to the rotational axis.
To manage that course of, Erik used an Arduino Nano board housed in a easy laser-cut field with a potentiometer for adjusting pace, and buttons to manage energy and the arm actuation. A beefy brushless DC motor spins up the flywheel beneath energy. Then, when it’s time to acquire that energy (akin to to energy the lightbulb Erik used for demonstration), that motor acts as a dynamo, like in a generator.
As a battery for long-term energy storage, this isn’t very sensible. In a vacuum with good frictionless bearings, it will be. However within the real-world the flywheel will decelerate by itself in brief order. Even so, it’s nonetheless an incredible illustration of the idea.
