Autonomous Boat Plots Lake Beds

Although the types of drones currently dominating headlines tend to be airborne, whether it’s hobbyist quadcopters, autonomous delivery vehicles, or military craft, autonomous vehicles can take nearly any transportation method we can think of. [Clay Builds] has been hard at work on his drone which is actually an autonomous boat, which he uses to map the underwater topography of various lakes. In this video he takes us through the design and build process of this particular vehicle and then demonstrates it in action.

The boat itself takes inspiration from sailing catamarans, which have two hulls of equal size connected above the waterline, allowing for more stability and less drag than a standard single-hulled boat. This is [Clay]’s second autonomous boat, essentially a larger, more powerful version of one we featured before. Like the previous version, the hulls are connected with a solar panel and its support structure, which also provides the boat with electrical power and charges lithium-iron phosphate batteries in the hull. Steering is handled by two rudders with one on each hull, but it also employs differential steering for situations where more precise turning is required. The boat carries a sonar-type device for measuring the water depth, which is housed in a more hydrodynamic 3d-printed enclosure to reduce its drag in the water, and it can follow a waypoint mission using a combination of GPS and compass readings.

Like any project of this sort, there was a lot of testing and design iteration that had to go into this build before it was truly seaworthy. The original steering mechanism was the weak point, with the initial design based on a belt connecting the two rudders that would occasionally skip. But after a bit of testing and ironing out these kinks, the solar boat is on its way to measure the water’s depths. The project’s code as well as some of the data can be found on the project’s GitHub page, and if you’re looking for something more human-sized take a look at this solar-powered kayak instead.

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TDK Claims Solid State Battery With 100X Energy Density

Regulations surrounding disposable batteries have accelerated a quiet race to replace coin cells, which on the whole are not readily rechargeable. TDK produces solid-state batteries and has announced a new material that claims an energy density of about 100 times that of their conventional batteries.

Energy density measures how much energy a system contains relative to its volume. The new battery has 1000 Wh/L. For comparison, old nickel-cadmium cells had about 150 Wh/L. A typical lithium-ion battery usually turns in about 200 – 250 Wh/L.

There aren’t many technical details, but a few things caught our interest. For one, it uses an oxide-based solid electrolyte and lithium alloy anodes. However, what really caught our eye was that it is “intended for use in wearables… that come in direct contact with the human body.” We don’t know if that means the material is safe for your skin or if it depends on being next to your body to operate.

While the energy density is high, keep in mind that the batteries of this type are usually tiny, so the total actual power available is probably not very high. Tiny batteries are definitely a thing. We are always hearing about breakthroughs, but we always wonder if and when we’ll see actual products.

Lithium-Ion Batteries Power Your Devboards Easily

Last summer, I was hanging out with a friend from Netherlands for a week, and in the middle of that week, we decided to go on a 20 km bike trip to a nearby beach. Problem? We wanted to chat throughout the trip, but the wind noise was loud, and screaming at each other while cycling wouldn’t have been fun. I had some walkie-talkie software in mind, but only a single battery-powered Pi in my possession. So, I went into my workshop room, and half an hour later, walked out with a Pi Zero wrapped in a few cables.

I wish I could tell you that it worked out wonders. The Zero didn’t have enough CPU power, I only had single-core ones spare, and the software I had in mind would start to badly stutter every time we tried to run it in bidirectional mode. But the battery power solution was fantastic. If you need your hack to go mobile, read on.

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Betavoltaic Battery Rated To Provide Power For 50 Years

A newly introduced battery called the BV100 by Chinese Betavolt Technology promises to provide half a century of power, at 100 μW in a 15x15x5 mm package. Inside the package are multiple, 2 micron-thick layers nickel-63 isotope placed between 10 micron-thick diamond semiconductor, with each diamond layer using the principle of betavoltaics to induce an electrical current in a similar fashion to a solar panel using light. Ni-63 is a β emitter with a half-life of 100 years, that decays into copper-63 (Cu-63), one of the two stable forms of copper.

From the battery’s product page we can glean a bit more information, such as that the minimum size of the betavoltaic battery is 3x3x0.03 mm with one layer of Ni-63 and two semiconductor layers, allowing for any number of layers to be stacked to increase the power output within a given package. Also noted is that the energy conversion rate of the β energetic event is about 8.8%, which could conceivably be improved in the future.

Although this battery may seem new, it’s actually based on a number of years of research  in diamond semiconductors in betavoltaics, with V. S. Bormashov and colleagues in 2018 reporting on a similar diamond semiconductor with Ni-63 isotope layer battery. They noted a battery specific energy of 3300 mWh/g. Related research by Benjian Liu and colleagues in 2018 showed an alphavoltaic battery, also using diamond semiconductor, which shows another possible avenue of development, since alpha particles are significantly more energetic.

Whether we’ll see Betavolt’s BV100 or similar products appear in commercial products is still uncertain, but they plan to have a 1 Watt version ready by 2025, which when packaged into the size of an average Li-ion battery pack could mean a mobile power source that will power more than a pacemaker, and cost less than the nuclear batteries powering the two Voyager spacecraft and all active Mars rovers today.

Recycling Batteries With Bacteria

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 (LiNixMnyCo1-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.

Wiring Up 100 Car Batteries So You Don’t Have To

We’re willing to bet most Hackaday readers have accidentally spot welded a few electrical contacts together over the years, complete with the surge of adrenaline that comes with the unexpected pops and sparks. It’s a mistake you’ll usually only make once or twice. But where most of us would look back at such mishaps as cautionary experiences, [Styropyro] sees an opportunity.

Armed with 100 car batteries wired in parallel, his recent video sees him pitting an assortment of household objects against the combined might of eighty-five thousand amps. Threaded rods, bolts, and angle iron all produce the sort of lightshow you’d expect, but [Styropyro] quickly discovered that holding larger objects down was more difficult than anticipated. It turns out that the magnetic fields being generated by the incredible amount of current rushing through the system was pulling the terminals apart and breaking the connection. After reinforcing the business end of his rig, he was able to tackle stouter objects such as crowbars and wrenches with explosive results.

A modified log splitter serves as a remotely operated switch.

We found that his remotely operated switch, built out of a hydraulic log splitter, to be a particular highlight of the video — unfortunately he only briefly goes over its construction at the very start. His side experiment, fashioning an sort of manually-operated carbon arc lamp with a pair of thick graphite electrodes and demonstrating is luminous efficacy compared to modern LEDs was an unexpected treat. As was the off-the-shelf domestic circuit breaker that impressed [Styropyro] by refusing to yield even after repeated jolts.

While the showers of sparks and vaporized metal might trigger some sweaty palms among the audience, we’ve seen [Styropyro] handle far scarier contraptions in the past. Though he may come off as devil-may-care in his videos, we figure there’s no way he could have made it this long without blinding or maiming himself if he didn’t know what he was doing.

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Non-Replaceable Battery? Not If This Proposed EU Law Passes!

A disturbing trend in consumer electronics has been a steady disappearance of replaceable batteries on our devices. Finding a mobile phone with a swapable battery is a struggle, and many other devices follow the trend by sealing in a Li-Po cell. The result is an ever-shorter life for electronics, and a greater problem with devices going to recycling or worse still, landfill. Hope is at hand though, thanks to a proposed European Union law that would if passed make batteries in appliances “designed so that consumers can easily remove and replace them themselves“.

In case any readers in the rest of the world wonder what it has to do with them, the EU represents such a huge market that manufacturers can neither ignore it, nor in most cases afford to make separate EU and rest-of-world versions of their products. Thus if the EU requires something for sale in its territories, in most cases it becomes the de facto norm for anything designed to be sold worldwide. We’ve already seen this with the EU’s right to repair legislation, and while we have not doubt that manufacturers will do their best to impede this new law we don’t think they will ultimately prevail.

Via 9to5Mac.