battery

417 Articles

Electric Truck Sets Racing Record

April 13, 2026 by 15 Comments

The 24 Hours of Le Mans races is an extremely prestigious endurance motorsport event which attracts the best cars and drivers from around the world. It’s one of the longest-running races too, taking place once a year since 1923 (with a few obvious understandable gaps). But, like most motorsports, it’s financially out of reach for most people. One of the more popular attempts to bring racing to the masses has been the 24 Hours of Lemons races, which have price limits on vehicles to keep the barrier to entry low, and an EV truck recently entered one of these races with some interesting results.

The group behind this vehicle is called Team Arcblast, who retrofitted an old Datsun pickup truck to the extreme to enter this race. The modestly sized electric motor is installed in between the cab and the bed for easy access to the driveshaft, with the engine bay repurposed for all of the cooling and radiators needed for endurance racing like this. They’ve also equipped the truck with plenty of efficiency-increasing spoilers and other aerodynamic parts, and rebuilt the cab with not only the required roll cage and other safety equipment, but a modified driving position with steering and other components from various Miatas.

The most impressive part of this build, however, is the battery. The team invented a method of swapping out batteries quickly to avoid having to fast charge the car in the pit area. The system lets a battery slide in to the middle of the truck above the motor and quickly connect to the electrical system allowing for very quick pit stops and the ability to charge other batteries while the race goes on. All of these modifications together allowed the team to break the EV record for a Lemons race.

For a Lemons race, though, even this truck stretches the original spirit that these races were started, however impressive the build. We published a primer to these types of races a while back which includes much more affordable internal combustion options.

Thanks to [JohnU] for the tip!

Continue reading “Electric Truck Sets Racing Record” →

This Flow Battery Operates With No Pump Required

March 27, 2026 by 6 Comments

Flow batteries are rather unique. They generate electricity by the combination of two fluids flowing on either side of a membrane. Typically, this involves the use of some kind of pump to get everything moving. However, [Dusan Caf] has demonstrated another way to make a flow battery operate.

[Dusan]’s build is a zinc-iodide flow battery. It uses two 3D printed reservoirs, each holding a ZnI2 solution and a graphite electrode. Unlike traditional flow batteries, there is no mechanism included to mechanically push the fluid around. Instead, fluid motion is generated by the magnetohydrodynamic effect, which you may know from that Japanese boat that didn’t work very well.

When charging the liquid-based cell, current flows through the conductive electrolyte that sits between both electrodes. This sees zinc electroplated onto the graphite anode, while iodide ions are oxidized at the cathode. There’s also a permanent magnet installed beneath the electrodes, which provides a stable magnetic field. This field, combined with the current flowing through the electrolyte, sees the Lorentz force pushing the electrolyte along, allowing the flow battery to operate. When the cell is being discharged, the reactions happen in reverse, with the flow through the electrodes changing direction in turn. Neatly, as current draw or supply increases, the flow rate increases in turn, naturally regulating the system.

[Dusan] notes this isn’t feasible for large batteries, due to the limited flow rate, but it’s fine for small-scale demos regarding the operation of a flow battery. We’ve featured some more typical flow battery designs in the past, too.

Continue reading “This Flow Battery Operates With No Pump Required” →

Gwiz car and vapes

Vape-powered Car Isn’t Just Blowing Smoke

March 4, 2026 by 12 Comments

Disposable vapes aren’t quite the problem/resource stream they once were, with many jurisdictions moving to ban the absurdly wasteful little devices, but there are still a lot of slightly-smelly lithium batteries in the wild. You might be forgiven for thinking that most of them seem to be in [Chris Doel]’s UK workshop, given that he’s now cruising around what has to be the world’s only vape-powered car.

Technically, anyway; some motorheads might object to calling donor vehicle [Chris] starts with a car, but the venerable G-Wiz has four wheels, four seats, lights and a windscreen, so what more do you want? Horsepower in excess of 17 ponies (12.6 kW)? Top speeds in excess of 50 Mph (80 km/h)? Something other than the dead weight of 20-year-old lead-acid batteries? Well, [Chris] at least fixes that last part.

The conversion is amazingly simple: he just straps his 500 disposable vape battery pack into the back seat– the same one that was powering his shop–into the GWiz, and it’s off to the races. Not quickly, mind you, but with 500 lightly-used lithium cells in the back seat, how fast would you want to go? Hopefully the power bank goes back on the wall after the test drive, or he finds a better mounting solution. To [Chris]’s credit, he did renovate his pack with extra support and insulation, and put all the cells in an insulated aluminum box. Still, the low speed has to count as a safety feature at this point.

Charging isn’t fast either, as [Chris] has made the probably-controversial decision to use USB-C. We usually approve of USB-Cing all the things, but a car might be taking things too far, even one with such a comparatively tiny battery. Perhaps his earlier (equally nicotine-soaked) e-bike project would have been a better fit for USB charging.

Thanks to [Vaughna] for the tip! Continue reading “Vape-powered Car Isn’t Just Blowing Smoke” →

There’s Always Room For 3D Printed Batteries

February 14, 2026 by 17 Comments

There are many applications where you have limits on how much you can cram into a particular space. There are also many applications where you need as much battery as you can get. At the intersection of those applications, you may soon be able to 3D print custom batteries to fit into oddly shaped spaces that might otherwise go to waste.

Commercial batteries are typically cylindrical or rectangular. In theory, you could build tooling to make batteries of any size or shape you want, but it’s an expensive process in small quantities. [Lawrence Ulrich] on Spectrum talks about a new process, developed by [Gabe Elias], that can print anodes, cathodes, separators, and casings for custom battery shapes with no costly tooling.

As an example, consider an unmanned aerial vehicle crammed with avionics. You could put off-the-shelf batteries in the wings, but you’ll end up wasting a lot of space. A custom battery could fill the wing’s interior completely. The post also mentions batteries shaped like the earpieces of a pair of smart glasses.

A prototype showed that in the space of 48 cylindrical cells, the new process could deliver a printed battery that uses 35% more of the available volume and a 50% boost in energy density.

Could you do this yourself? Maybe, but it won’t be trivial. The current process requires a liquid electrolyte and the ability to produce thin layers of exotic materials. What oddly-shaped battery would you like to see? Us? We’d like to have a battery for a laptop that was spread uniformly so there wasn’t a heavy side that has the battery.

A Working Intercom From Antique Telephones

February 9, 2026 by 13 Comments

Although it can be hard to imagine in today’s semiconductor-powered, digital world, there was electrical technology around before the widespread adoption of the transistor in the latter half of the 1900s that could do more than provide lighting. People figured out clever ways to send information around analog systems, whether that was a telegraph or a telephone. These systems are almost completely obsolete these days thanks to digital technology, leaving a large number of rotary phones and other communications systems relegated to the dustbin of history. [Attoparsec] brought a few of these old machines back to life anyway, setting up a local intercom system with technology faithful to this pre-digital era.

These phones date well before the rotary phone that some of us may be familiar with, to a time where landline phones had batteries installed in them to provide current to the analog voice circuit. A transformer isolated the DC out of the line and amplified the voice signal. A generator was included in parallel which, when operated by hand, could ring the other phones on the line. The challenge to this build was keeping everything period-appropriate, with a few compromises made for the batteries which are D-cell batteries with a recreation case. [Attoparsec] even found cloth wiring meant for guitars to keep the insides looking like they’re still 100 years old. Beyond that, a few plastic parts needed to be fabricated to make sure the circuit was working properly, but for a relatively simple machine the repairs were relatively straightforward.

The other key to getting an intercom set up in a house is exterior to the phones themselves. There needs to be some sort of wiring connecting the phones, and [Attoparsec] had a number of existing phone wiring options already available in his house. He only needed to run a few extra wires to get the phones located in his preferred spots. After everything is hooked up, the phones work just as they would have when they were new, although their actual utility is limited by the availability of things like smartphones. But, if you have enough of these antiques, you can always build your own analog phone network from the ground up to support them all.

Continue reading “A Working Intercom From Antique Telephones” →

Pendulum Powered Battery

February 8, 2026 by 23 Comments

While the average person would use a standard charger to top off their phone, [Tom Stanton] is no average man. Instead, he put mind to matter with an entire pendulum battery system.

Using the inductive effects of magnets on copper coils, [Tom] found the ability to power small components. With that in mind, the only path was forward with a much larger pendulum. A simple diode rectifier and capacitors allow for a smoother voltage output. The scale of the device is still too small to power anything insane, even the phone charging test is difficult. One thing the device can do is juice up the electromagnetic launcher he put together a couple years back to hurl an RC plane into the air.

The useful applications of pendulum power storage might not be found in nationwide infrastructure, but the application on this scale is certainly a fun demonstration. [Tom] has a particular fascination with similar projects where practical application comes second to novelty. For a perfect example of this, check out his work with air powered planes!

Continue reading “Pendulum Powered Battery” →

Investigating The Science Claims Behind The Donut Solid State Battery

February 8, 2026 by 63 Comments

Earlier this year Donut Lab caused quite the furore when they unveiled what they claimed was the world’s first production-ready solid state battery, featuring some pretty stellar specifications. Since then many experts and enthusiasts in the battery space have raised concerns that this claimed battery may not be real, or even possible at all. After seeing the battery demonstrated at CES’26 and having his own concerns, [Ziroth] decided to do some investigating on what part of the stated claims actually hold up when subjected to known science.

On paper, the Donut Lab battery sounds amazing: full charge in less than 10 minutes, 400 Wh/kg energy density, 100,000 charge cycles, extremely safe and low cost. Basically it ticks every single box on a battery wish list, yet the problem is that this is all based on Donut’s own claims. Even aside from the concerns also raised in the video about the company itself, pinning down what internal chemistry and configuration would enable this feature set proves to be basically impossible.

In this summary of research done on Donut’s claimed battery as well as current battery research, a number of options were considered, including carbon nanotube-based super capacitors. Yet although this features 418 Wh/kg capacity, this pertains only to the basic material, not the entire battery which would hit something closer to 50 Wh/kg.

Continue reading “Investigating The Science Claims Behind The Donut Solid State Battery” →