a) Schematic illustration of energy storage process of succulent plants by harnessing solar energy with a solar cell, and the solar cell converts the energy into electricity that can be store in APCSCs of succulent plants, and then utilized by multiple electrical appliances. b–d) The energy is stored in cactus under sunlight by solar cell and then power light strips of Christmas tree for decoration.

Succulents Into Supercapacitors

January 11, 2024 by Navarre Bartz 17 Comments

Researchers in Beijing have discovered a way to turn succulents into supercapacitors to help store energy. While previous research has found ways to store energy in plants, it often required implants or other modifications to the plant itself to function. These foreign components might be rejected by the plant or hamper its natural functions leading to its premature death.

This new method takes an aloe leaf, freeze dries it, heats it up, then uses the resulting components as an implant back into the aloe plant. Since it’s all aloe all the time, the plant stays happy (or at least alive) and becomes an electrolytic supercapacitor.

Using the natural electrolytes of the aloe juice, the supercapacitor can then be charged and discharged as needed. The researchers tested the concept by solar charging the capacitor and then using that to run LED lights.

This certainly proposes some interesting applications, although we think your HOA might not be a fan. We also wonder if there might be a way to use the photosynthetic process more directly to charge the plant? Maybe this could recharge a tiny robot that lands on the plants?

Aqueous Battery Solves Lithium’s Problems

January 4, 2024 by Bryan Cockfield 15 Comments

The demand for grid storage ramps up as more renewable energy sources comes online, but existing technology might not be up to the challenge. Lithium is the most popular option for battery storage right now, not just due to the physical properties of the batteries, but also because we’re manufacturing them at a massive scale already. Unfortunately they do have downsides, especially with performance in cold temperatures and a risk of fires, which has researchers looking for alternatives like aqueous batteries which mitigate these issues.

An aqueous battery uses a water-based electrolyte to move ions from one electrode to the other. Compared to lithium, which uses lithium salts for the electrolyte, this reduces energy density somewhat but improves safety since water is much less flammable. The one downside is that during overcharging or over-current situations, hydrogen gas can be produced by electrolysis of the water, which generally needs to be vented out of the battery. This doesn’t necessarily damage the battery but can cause other issues. To avoid this problem, researchers found that adding a manganese oxide to the battery and using palladium as a catalyst caused any hydrogen generated within the battery’s electrolyte to turn back into water and return to the electrolyte solution without issue.

Of course, these batteries likely won’t completely replace lithium ion batteries especially in things like EVs due to their lower energy density. It’s also not yet clear whether this technology, like others we’ve featured, will scale up enough to be used for large-scale applications either, but any solution that solves some of the problems of lithium, like the environmental cost or safety issues, while adding more storage to an increasingly renewable grid, is always welcome.

Building A Rad Super Capacitor RC Plane

December 25, 2023 by Lewin Day 15 Comments

[Tom Stanton] is a fan of things like rubber band planes, and has built many of his own air-powered models over the years. Now, he’s built a model powered by a supercapacitor for a thoroughly modern twist on stored-energy flying toys.

It’s not a wholly original idea; [Tom] was inspired by a toy he bought off-the-shelf. His idea, though, was to make one that could be hand-cranked to charge it to make it more like the rubber-band planes of old. He thus built his own geared generator for the job using a big pile of magnets and 3D printed components. It’s capable of putting out around 17 volts when cranked at a reasonable speed. Hooked up to the toy plane, his hand-crank generator was able to fully charge the plane in just a few turns.

His generator was really overkill for the small toy, though. Thus, he elected to build himself a much larger supercapacitor-powered model. He wired up a pack of six supercapacitors in series, designed for roughly 18 volts. The pack was given balance leads to ensure that no individual capacitor was charged beyond its 3.0 V rating. The pack was placed inside a nice aerodynamic printed fuselage. The plane was then given a brushless motor and prop, speed controller, servos, and an RC receiver. Indeed, far from a simple throwable model, it’s a fully flyable RC plane.

The plane is quite a capable flyer with plenty of power, but a fairly short run time of just under two minutes. Though, with that said, it can be recharged in just about that same amount of time thanks to its supercapacitor power supply. [Tom] reckons it should be capable of a 1:1 crank time to flight time ratio in ideal conditions.

Supercapacitors are super cool, but we don’t see enough of them. They’ve popped up here and there, and obviously have many important applications, but we’re not sure they’ve had a real killer app in the consumer space. XV Racers were killer fun, though. Continue reading “Building A Rad Super Capacitor RC Plane” →

Open Source DC UPS Keeps The Low-Voltage Gear Going

December 22, 2023 by Dan Maloney 26 Comments

We all like to keep our network gear running during a power outage — trouble is, your standard consumer-grade uninterruptible power supply (UPS) tends to be overkill for routers and such. Their outlet strips built quickly get crowded with wall-warts, and why bother converting from DC to AC only to convert back again?

This common conundrum is the inspiration for [Walker]’s DC UPS design, which has some interesting features. First off, the design is open source, which of course invites tinkering and repurposing. The UPS is built for a 12 volt supply and load, but that obviously can be changed to suit your needs. The battery bank is a 4S3P design using 18650 cells, and that could be customized as well. There’s an ideal diode controller that prevents DC from back-feeding into the supply when the lights go out, and a really interesting synchronous buck-boost converter in place of the power management chip you’d normally see in a UPS. The converter chip takes a PWM signal from an RP2040; there’s also an ESP32 onboard for web server and UI duties as well as an STM32 to run the BMS. The video below discusses the design and shows a little of the build.

We’ve seen a spate of DC UPS designs lately, some more elaborate than others. This one has quite a few interesting chips that most of us don’t normally deal with, and it’s nice to see how they’re used in a practical design.

Continue reading “Open Source DC UPS Keeps The Low-Voltage Gear Going” →

Tesla’s Plug Moves Another Step Closer To Dominance

December 21, 2023 by Navarre Bartz 46 Comments

Charging an EV currently means making sure you find a station with the right plug. SAE International has now published what could be the end to the mishmash of standards in North America with the J3400 North American Charging Standard.

The SAE J3400TM North American Charging Standard (NACS) Electric Vehicle Coupler Technical Information Report (TIR), which just rolls off the tongue, details the standard formerly only available on Tesla vehicles. We previously talked about the avalanche of support from other automakers this year for the connector, and now that the independent SAE standard has come through, the only major holdout is Stellantis.

Among the advantages of the NACS standard over the Combined Charging System (CCS) or CHAdeMO is a smaller number of conductors given the plug’s ability to carry DC or AC over the same wires. Another benefit is the standard using 277 V which means that three separate Level 2 chargers can be placed on a single 3-phase commercial line with no additional step down required. Street parkers can also rejoice, as the standard includes provisions for lampost-based charger installations with a charge receptacle plug instead of the attached cable required by J1772 which leads to maintenance, clutter, and ADA concerns.

Now that J3400/NACS is no longer under the purview of a single company, the Federal Highway Administration has announced that it will be looking into amending the requirements for federal charger installation subsidies. Current rules require CCS plugs be part of the installation to qualify for funds from the Bipartisan Infrastructure Bill.

If you want to see how to spice up charging an EV at home, how about this charging robot or maybe try fast charging an e-bike from an electric car plug?

Recycling Batteries With Bacteria

December 18, 2023 by Navarre Bartz 6 Comments

Vehicle battery recycling is going to be a big deal with all the electric cars hitting the roads. What if you could do it more effectively with the power of microbes? (via Electrek)

“Li-ion” vehicle batteries can be any of a number of different chemistries, with more complex cathode makeups, like NCM (LiNi_xMn_yCo_1-x-yO₂), being understandably more complex to separate into their original constituents. Researchers and companies in the industry are hoping to find economically-viable ways to get these metals back for both the environmental and economic benefits a closed loop system could provide.

Researchers in the UK developed a method using two species of bacteria to precipitate Ni, Mn, and Co from the liquid leached from cathodes. Li remained in the liquid where it could be processed separately like that obtained in Li brine. Mn was precipitated first by S. oneidensis MR-1, and a following step removed Ni and Co with D. alaskensis G20. The researchers report that Ni and Co show promise for further separation via biological methods, but more research is required for this step.

If you’re looking for some more interesting ways bacteria can be harnessed for the energy system, checkout this microbial fuel cell, another using soil, and an enzyme derived from bacteria that can pull electricity from thin air.

Second Life UPS Mark II: A UPS For Low-Voltage DC Applications

December 17, 2023 by Maya Posch 17 Comments

When you have a whole stack of devices and appliances that all have an AC to DC adapter and which you’d like to put on an uninterruptable power supply (UPS), you could do the obvious thing and get an off-the-shelf UPS with myriad AC outputs. In the case of a 19″ rack this means wrangling a power strip or two and any combination of differently sized AC/DC adapters into the rack, with questionable efficiency and waste heat dumped into the rack. This is where a DC-only UPS like [Maciej Grela]’s Second Life UPS Mark II provides an interesting alternative.

At its core it’s a pretty simple concept: A single 400Watt power supply handles the AC/DC conversion from mains to 24 VDC, which feeds the battery charger as well as the outputs. These outputs include 5 VDC, 12 VDC and V_rail, with the latter being either the output from the PSU, or the battery voltage. In case of AC power failure, an LT4416 dual power path controller handles the switch-over from the PSU output to the internal batteries. In the article, [Maciej] covers how the buck modules for the 12 & 5 VDC rails were sized, along with the conversion of an old rack-mounted network switch into a UPS. Continue reading “Second Life UPS Mark II: A UPS For Low-Voltage DC Applications” →