Lumafield Shows Why Your Cheap 18650 Cells Are Terrible

September 29, 2025 by Jenny List 3 Comments

Lithium-ion cells deliver very high energy densities compared to many other battery technologies, but they bring with them a danger of fire or explosion if they are misused. We’re mostly aware of the battery conditioning requirements to ensure cells stay in a safe condition, but how much do we know about the construction of the cells as a factor? [Lumafield] is an industrial imaging company, and to demonstrate their expertise, they’ve subjected a large number of 18650 cells from different brands to a CT scan.

The construction of an 18650 sees the various layers of the cell rolled up in a spiral inside the metal tube that makes up the cell body. The construction of this “jellyroll” is key to the quality of the cell. [Lumafield’s] conclusions go into detail over the various inconsistencies in this spiral, which can result in cell failure. It’s important that the edges of the spiral be straight and that there is no electrode overhang. Perhaps unsurprisingly, they find that cheap no-name cells are poorly constructed and more likely to fail, but it’s also interesting to note that these low-quality cells also have fewer layers in their spiral.

We hope that none of you see more of the inside of a cell in real life than you have to, as they’re best left alone, but this report certainly sheds some light as to what’s going on inside a cell. Of course, even the best cells can still be dangerous without protection.

Two Decades Of Hackaday In Words

September 29, 2025 by Jenny List 16 Comments

I think most of us who make or build things have a thing we are known for making. Where it’s football robots, radios, guitars, cameras, or inflatable textile sculptures, we all have the thing we do. For me that’s over the years been various things but has recently been camera hacking, however there’s another thing I do that’s not so obvious. For the last twenty years, I’ve been interested in computational language analysis. There’s so much that a large body of text can reveal without a single piece of AI being involved, and in pursuing that I’ve created for myself a succession of corpus analysis engines. This month I’ve finally been allowed to try one of them with a corpus of Hackaday articles, and while it’s been a significant amount of work getting everything shipshape, I can now analyse our world over the last couple of decades.

The Burning Question You All Want Answered

A graph of "arduino" versis "raspberry", comparing Arduino and Raspberry Pi coverage over time. — Battle of the Boards, over the decades.

A corpus engine is not clever in its own right, instead it will simply give you straightforward statistics in return for the queries you give it. But the thing that keeps me coming back for more is that those answers can sometimes surprise you. In short, it’s a machine for telling you things you didn’t know. To start off, it’s time to settle a Hackaday trope of many years’ standing. Do we write too much about Arduino projects? Into the engine goes “arduino”, and for comparison also “raspberry”, for the Raspberry Pi.

What comes out is a potted history of experimenter’s development boards, with the graph showing the launch date and subsequent popularity of each. We’re guessing that the Hackaday Arduino trope has its origins in 2011 when the Italian board peaked, while we see a succession of peaks following the launch of the Pi in 2012. I think we are seeing renewals of interest after the launch of the Pi 3 and Pi 4, respectively. Perhaps the most interesting part of the graph comes on the right as we see both boards tail off after 2020, and if I had to hazard a guess as to why I would cite the rise of the many cheap dev boards from China.

Continue reading “Two Decades Of Hackaday In Words” →

Decorate Your Neck With The First Z80 Badge

September 28, 2025 by Jenny List 4 Comments

Over the years, we’ve brought you many stories of the creative artwork behind electronic event badges, but today we may have a first for you. [Spencer] thinks nobody before him has made a badge powered by a Z80, and we believe he may be right. He’s the originator of the RC2014 Z80-based retrocomputer, and the badge in question comes from the recent RC2014 Assembly.

Fulfilling the function of something you can write your name on is a PCB shaped like an RC2014 module, with LEDs on all the signal lines. It could almost function as a crude logic analyser for the system, were the clock speed not far too high to see anything. To fix this, [Spencer]’s badge packs a single-board RC2014 Micro with a specially slow clock, and Z80 code to step through all memory addresses, resulting in a fine set of blinkenlights.

Thus was created the first Z80-based event badge, and we’re wondering whether or not it will be the last. If you’re curious what this RC2014 thing is about, we reviewed the RC2014 Micro when it came out.

Drones At Danish Airports, A Plea For Responsible Official Response

September 27, 2025 by Jenny List 46 Comments

In Europe, where this is being written, and possibly further afield, news reports are again full of drone sightings closing airports. The reports have come from Scandinavia, in particular Denmark, where sightings have been logged across the country. It has been immediately suggested that the Russians might somehow be involved, something they deny, which adds a dangerous geopolitical edge to the story.

To us here at Hackaday, this is familiar territory. Back in the last decade, we covered the saga of British airports closing due to drone sightings. In that case, uninformed hysteria played a large part in the unfolding events, leading to further closures. The problem was that the official accounts did not seem credible. Eventually, after a lot of investigation and freedom of information requests by the British drone community, there was a shamefaced admission that there had never been any tangible evidence of a drone being involved.

Continue reading “Drones At Danish Airports, A Plea For Responsible Official Response” →

NEC V20: The Original PC Processor Upgrade

September 27, 2025 by Jenny List 14 Comments

In the early 1980s, there was the IBM PC, with its 4.77 MHz Intel 8088 processor. It was an unexpected hit for the company, and within a few years there were a host of competitors. Every self-respecting technology corporation wanted a piece of the action including processor manufacturers, and among those was NEC with their V20 chip and its V30 sibling. From the outside they were faster pin-compatible 8088 and 8086 clones, but internally they could also run both 8080 and 80186 code. [The Silicon Underground] has a look back at the V20, with some technical details, history, and its place as a PC upgrade.

For such a capable part it’s always been a surprise here that it didn’t take the world by storm, and the article sheds some light on this in the form of an Intel lawsuit that denied it a critical early market access. By the time it was available in quantity the PC world had moved on from the 8088, so we saw it in relatively few machines. It was a popular upgrade for those in the know back in the day though as it remains in 2025, and aside from its immediate speed boost there are a few tricks it lends to a classic PC clone. The version of DOS that underpinned Windows 95 won’t run on an 8086 or 8088 because it contains 8016 instructions, but a V20 can run it resulting in a much faster DOS experience. One to remember, if an early PC or clone cones your way.

Hungry for the good old days of DOS? You don’t need to find 80s hardware for that.

Steamboat Willie Still Tests Copyright

September 26, 2025 by Jenny List 18 Comments

If you know anything about Mickey Mouse, you’ll be able to tell us that his first outing was in 1928’s Steamboat Willie — an animated short that sees our hero as the hapless pilot of a riverboat battling an assortment of animals and his captain. It entered the public domain last year, meaning that it and the 1928 incarnation of Mickey are now free of any copyright obligation to the media giant.

There’s an interesting development from Florida on that front though as it seems Disney may have been testing this through legal means, and now a law firm wants to see them in court over their proposed use of the film in an advert.

Of course here at Hackaday we don’t cover the dry subject of Florida legal news as a rule, but we are interested in the world of copyright as it applies to many other things that do come under our eye. As we understand it the law firm is requesting the judge assert their protection from trademark claims over the use of Disney’s 1928 Willie, given that there have been claims from the entertainment giant against others doing the same thing.

It’s hardly surprising that a large corporation might seek to use legal muscle and trademark law to de facto extend the term of Mickey’s protection beyond the defined copyright expiration date, so for once it’s refreshing to see them come up against someone unafraid of a courtroom.

We hope that common sense will prevail, and this undermining of a cherished right (not to mention prior case law) is not allowed to succeed. Meanwhile if you’d like a 1928 Mickey that Disney have shied away from coming after, look no further than the EFF.

Retrotechtacular: The Ferguson System

September 24, 2025 by Jenny List 37 Comments

Of the many great technological leaps made in the middle of the 20th century, one of the ones with perhaps the greatest impact on our modern life takes a back seat behind the more glamorous worlds of electronics, aeronautics, or computing. But the ancestor of the modern tractor has arguably had more of an impact on the human condition in 2025 than that of the modern computer, and if you’d been down on the farm in the 1940s you might have seen one.

The Ferguson system refers to the three-point implement linkage you’ll find on all modern tractors, the brainchild of the Irish engineer Harry Ferguson. The film below the break is a marketing production for American farmers, and it features the Ford-built American version of the tractor known to Brits and Europeans as the Ferguson TE20.

The evolution of the tractor started as a mechanisation of horse-drawn agriculture, using either horse-drawn implements or ones derived from them. While the basic shape of a modern tractor as a four wheel machine with large driving wheels at the rear evolved during this period, other types of tractor could be found such as rein-operated machines intended to directly replace the horse, or two-wheeled machines with their own ecosystem of attachments.

As the four-wheeled machines grew in size and their implements moved beyond the size of their horse-drawn originals, they started to encounter a new set of problems which the film below demonstrates in detail. In short, a plough simply dragged by a tractor exerts a turning force on the machine, giving the front a tendency to lift and the rear a lack of traction. The farmers of the 1920s and 1930s attempted to counter this by loading their tractors with extra weights, at the expense of encumbering them and compromising their usefulness. Ferguson solved this problem by rigidly attaching the plough to the tractor through his three-point linkage while still allowing for flexibility in its height. The film demonstrates this in great detail, showing the hydraulic control and the feedback provided through a valve connected to the centre linkage spring. Continue reading “Retrotechtacular: The Ferguson System” →