battery

372 Articles

Clay Makes For DIY Power Source, Just Add Water

June 15, 2023 by 17 Comments

[Robert Murray] starts out showing us some clay formations that house bees. He couldn’t take any of that clay home, but that’s no problem — clay is plentiful, and apparently, you can make a battery with it. Well, perhaps not really a battery. Adding water to zeolite — a clay often used as a filter material — generates heat, and where there’s heat, there can be electricity.

[Robert] uses a salvaged Peltier device, as you find in small electric refrigerators. These solid-state heat pumps usually convert electricity into a temperature differential, but in this case, it is used as a thermocouple, generating electricity from a temperature difference.

The clay used is a very fine aluminosilicate crystal known as zeolite 13X. Once it comes into contact with plain ordinary water, it immediately starts to boil. It’s a neat experiment, and with the Peltier underneath the metal container holding the clay, enough power is produced to spin a small motor. Of course this won’t power anything large, but on the other hand, plenty of things these days don’t take much power. This technique would work with any exothermic reaction of course, but there’s something compelling about the shelf-stability of water and clay.

Beats a potato, we suppose. Batteries don’t have to be difficult to make. It is only hard to make really good ones.

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Harvesting Rechargeable Batteries From Single-Use Devices

June 7, 2023 by 63 Comments

The price of lithium batteries has plummeted in recent years as various manufacturers scale up production and other construction and process improvements are found. This is a good thing if you’re an EV manufacturer, but can be problematic if you’re managing something like a landfill and find that the price has fallen so low that rechargeable lithium batteries are showing up in the waste stream in single-use devices. Unlike alkaline batteries, these batteries can explode if not handled properly, meaning that steps to make sure they’re disposed of properly are much more important. [Becky] found these batteries in single-use disposable vape pens and so set about putting them to better use rather than simply throwing them away.

While she doesn’t use the devices herself, she was able to source a bunch of used ones locally from various buy-nothing groups. Disassembling the small vape pens is fairly straightforward, but care needed to be taken to avoid contacting some of the chemical residue inside of the devices. After cleaning the batteries, most of the rest of the device is discarded. The batteries are small but capable and made of various lithium chemistries, which means that most need support from a charging circuit before being used in any other projects. Some of the larger units do have charging circuitry, though, but often it’s little more than a few transistors which means that it might be best for peace-of-mind to deploy a trusted charging solution anyway.

While we have seen projects repurposing 18650 cells from various battery packs like power tools and older laptops, it’s not too far of a leap to find out that the same theory can be applied to these smaller cells. The only truly surprising thing is that these batteries are included in single-use devices at all, and perhaps also that there are few or no regulations limiting the sale of devices with lithium batteries that are clearly intended to be thrown away when they really should be getting recycled.

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Vehicle-to-Grid Made Easy

May 25, 2023 by 37 Comments

As electric cars continue to see increased adoption, one associated technology that was touted long ago that still hasn’t seen widespread adoption is vehicle-to-grid or vehicle-to-home. Since most cars are parked most of the time, this would allow the cars to perform load-levelling for the grid or even act as emergency generators on an individual basis when needed. While this hasn’t panned out for a variety of reasons, it is still possible to use an EV battery for use off-grid or as part of a grid tie solar system, and now you can do it without needing to disassemble the battery packs at all.

Normally when attempting to use a scrapped EV battery for another use, the cells would be removed from the OEM pack and reorganized to a specific voltage. This build, however, eliminates the need to modify the packs at all. A LilyGO ESP32 is used to convert the CAN bus messages from the battery pack to the Modbus communications protocol used by the inverters, in this case a Fronius Gen24, so the inverter and battery can coordinate energy delivery from one to the other automatically. With the hard part out of the way, the only other requirements are to connect a high voltage DC cable from the battery pack to the inverter.

[Dala], the creator of this project, has taken other steps to ensure safety as well that we’d recommend anyone attempting to recreate this build pays close attention to, as these battery packs contain an extremely large amount of energy. The system itself supports battery packs from Nissan Leafs as well as the Tesla Model 3, which can usually be found for comparably low prices. Building battery energy storage systems to make up for the lack of commercially-available vehicle-to-home systems isn’t the only use for an old EV battery, though. For example, it’s possible to use Leaf batteries to triple the range of other EVs like [Muxsan] did with this Nissan van.

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The Voltaic Pile: Building The First Battery

May 25, 2023 by 11 Comments

In the technologically-underpinned modern world, most of us interact with a battery of some sort every day. Whether that’s the starter battery in a car, the lithium battery in a phone, or even just the coin cell battery in a wrist watch, batteries underpin a lot of what makes society possible now. Not so in the early 1800s when chemists and physicists were first building and experimenting with batteries. And those batteries were enormous, non-rechargable, and fairly fragile to boot. Not something suited for powering much of anything, but if you want to explore what it would have been like to use one of these devices, follow along with [Christopher]’s build of a voltaic pile. Continue reading “The Voltaic Pile: Building The First Battery” →

Battery Bot Makes Sure Cordless Tool Packs Are Always Topped Up

May 24, 2023 by 19 Comments

There was a time not that long ago when every tool was cordless. But now, cordless power tools have proliferated to the point where the mere thought of using a plain old wrist-twisting screwdriver is enough to trigger a bout of sympathetic repetitive injury. And the only thing worse than that is to discover that the batteries for your tools are all dead.

As [Lance] from the “Sparks and Code” channel freely admits, the fact that his impressive collection of batteries is always dead is entirely his fault, and that’s what inspired his automatic battery charging robot. The design is pretty clever; depleted batteries go into a hopper, under which is a 3D-printed sled. Batteries drop down into the sled, which runs the battery out from under the hopper to the charging station, which is just the guts of an old manual charger attached to a lead screw to adjust the height of the charging terminals for different size batteries. When the battery is charged, the sled pushes it a little further into an outfeed hopper before going back to get another battery from the infeed side.

Of course, that all vastly understates the amount of work [Lance] had to put into this. He suffered through a lot of “integration hell” problems, like getting the charger properly connected to the Arduino running the automation. But with a lot of tweaking, he can now just dump in a bunch of depleted packs and let the battery bot handle everything. The video after the break shows all the gory details.

Of course, there’s another completely different and much simpler solution to the dead battery problem.

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The Thousand Year (Radioactive) Diamond Battery

May 22, 2023 by 44 Comments

The Holy Grail of battery technology is a cell which lasts forever, a fit-and-forget device that never needs replacing. It may seem a pipe-dream, but University of Bristol researchers have come pretty close. The catch? Their battery lasts a very long time, but it generates micropower, and it’s radioactive.

They’re using a thin layer of vapour-deposited carbon-14 diamond both as a source of beta radiation, and as a semiconductor material which harvests those electrons. They’re expected to be used for applications such as intermittent sensors, where they would slowly charge a supercapacitor which could release useful amounts of power in short bursts.

It’s being touted as an environmental win because the carbon-14 is sourced from radioactive waste, but against that it’s not unreasonable to have a concern about the things being radioactive. The company commercializing the tech leads with the bold question: “What would you do with a power-cell that outlasts the device it powers?“, to which we would hope the answer won’t be “Throw it away to be a piece of orphaned radioactive waste in the environment when the device it powers is outlasted”. We’ll have to wait and see whether devices containing these things turn up on the surplus market in a couple of decades.

Fortunately the carbon-14 lives not in cartoonish vats of radioactive green slime but safely locked away in diamond, about the safest medium for it to be in. The prototype devices are also tiny, so we’re guessing that the quantity of carbon-14 involved is also small enough to not be a problem. We’re curious though whether they could become a valuable enough commodity to be reused and recycled in themselves, after all something that supplies energy for decades could power several different devices over its lifetime. Either way, it’s a major improvement over a tritium cell.

Inside A Pair Of Smart Sunglasses

May 6, 2023 by 14 Comments

If you’re willing to spend $200 USD on nothing more than 100 grams of plastic, there are a few trendy sunglasses brands that are ready to take your money before you have time to think twice. Sure, you can get a pair of sunglasses for an order of magnitude less money that do the exact same job, but the real value is in the brand stamped into the plastic and not necessarily the sunglasses themselves. Not so with this pair of Ray-Bans, though. Unlike most of their offerings, these contain a little bit more than a few bits of stylish plastic and [Becky Stern] is here to show us what’s hidden inside.

At first glance, the glasses don’t seem to be anything other than a normal pair of sunglasses, if a bit bulky But on closer inspection they hide a pair of cameras and a few other bits of electronics similar to the Google Glass, but much more subtle. The teardown demonstrates that these are not intended to be user-repairable devices, and might not be repairable at all, as even removing the hinges broke the flexible PCBs behind them. A rotary tool was needed to remove the circuit boards from the ear pieces, and a bench vice to remove the camera modules from the front frame. We can presume these glasses will not be put back together after this process.

Hidden away inside is a pair of cameras, a Snapdragon quad-core processor, capacitive touch sensors, an amplifier for a set of speakers. Mostly this is to support the recording of video and playback of audio, and not any sort of augmented reality system like Google Glass attempted to create. There are some concerning ties with Facebook associated with this product as well which will be a red flag for plenty of us around here, but besides the privacy issues, lack of repairability, and lack of features, we’d describe it as marginally less useful as an entry-level smartwatch. Of course, Google Glass had its own set of privacy-related issues too, which we saw some clever projects solve in unique ways.

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