On The Wisdom Of Replacing A NiMH Module In A Prius Battery Pack

Old versus new Prius NiMH module. (Credit: HubNut, YouTube)
Old versus new Prius NiMH module. (Credit: HubNut, YouTube)

It’s possible to get a pretty good deal on used Toyota Prius cars, but as with all hybrid cars that also means a used battery pack and resulting issues. In the case of the Gen 2 Prius that [HubNut] recently acquired it was clear that its battery was effectively toast, with the engine running constantly and the car often giving up due to detected issues with the pack. After getting to an EV-focused garage for repairs, a spare NiMH module was used to replace a problematic module to bring it back to good health, while raising the question of how sensible such a repair is.

Certainly, compared to the average BEV where a much larger battery is generally integrated well into the frame, a Prius makes things very easy, with the compact battery readily accessible and removable from the trunk. It is also a very modular battery, with some elbow grease and bolt-twisting enough to disassemble it.

Even with that it still a high-voltage battery with all the associated risks, and as raised in the comments there’s a big question about putting a new(er) cell into a pack with more worn-out NiMH cells as generally the cells wear out fairly evenly. While this fix can give the pack some more life, the new cell won’t match the internal resistance and other parameters of the pack, leading to issues like voltage drift. Then there’s the issue that if one cell failed, others probably aren’t far behind, so this hack would soon become a regular ritual.

Much like swapping one bad 18650 Li-ion cell in a bigger battery, it’s probably a more sustainable solution to simply replace the entire battery at once, or at least replace all modules or cells to properly refurbish it. For [HubNut] this fix suffices because he suspects that this pack was already assembled from random modules, it’s an important consideration to make if you don’t enjoy ending up stranded during a trip.

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Know Your Food: Cheesemaking

There’s a thing that people who grew up on farms all share: a connection with food production that isn’t some mystical rose-tinted woo from a TV chef, but instead a practical general knowledge from being there on the ground. A glance at a crop in a field and you immediately recognise what it is, if it’s ploughing time you’ll know the soil type, and there’s always either too little, or too much rain. For a given foodstuff you’ll know far too much about where it came from, because if your dad wasn’t involved in its production, the chances are someone he knew was. You take this for granted, after all doesn’t everyone have this general knowledge? Seemingly not.

Hackaday is not a cooking channel, but I know we’re all interested here in how things are made. Shouldn’t that also extend to what we eat? It’s fashionable to follow a back-to-nature line that all commercial foodstuffs are somehow over-processed junk, but without the requisite knowledge you’re flying blind there. To know both how common foodstuffs should be made, as well as how they are made industrially, should be an essential for everyone.

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Like A Wire Bender, But For Pop Tubes

Are you familiar with pop tubes? Resembling the corrugated section of a bendy straw, they are at the core of PopTuber, an intriguing research project from the Actuated Experience Lab at the University of Chicago.

With five motors and specialized gears a pop tube can be formed into complex, arbitrary shapes, and just as easily reset.

PopTuber shows how five motors and some specialized gears are all it takes to bend pop tubes into complex and stable 3D shapes. One can design the shapes in software, feed a pop tube into the shaper, and watch the device do the work. Importantly, the device can just as easily reset and re-use the tube. Watch the video (embedded below the page break) to see it in action and get a feel for what it can do.

In concept, it’s a little like a wire-bending machine, although wire benders are bulkier in comparison, more complex to scale, and unbending a wire is a separate process with its own hardware.

This project explores possibilities for a machine that can crank out complex curves on demand, such as oddball user interfaces, physical prototyping, and even a strange sort of physical display. But the real forward-thinking and interesting question researchers asked is whether this idea could be a form of programmable matter. The project shows that five actuators in a relatively compact package are all that’s needed to shape (and reset) a pop tube of arbitrary length in a programmable way, and it can scale easily to different sizes.

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Revisiting Making Your Own Internet Router In 2026

After my recent misadventures setting up an OpenWrt installation on a scruffy e-waste-level x86 PC, quite a few people chimed in with feedback, criticism and friendly hostility regarding things like a presumed ‘x86 bias’. There were also some system-related things that simply didn’t seem to want to work, such as booting from an SD card with a USB adapter, which cut short a lot of the actual OpenWrt testing that I had intended. This made it mostly an enlightening look at what issues you can run into when ‘quickly’ throwing an OpenWrt router together with some junk parts these days.

In this second article I’ll try to address as many of these points as possible, as well as attempt to show off an actual working OpenWrt installation in action. In addition, since just using random junk x86 PC parts was the way to go back in the late 90s/early 2000s doesn’t mean that this is still the way in 2026, so I’ll be taking a look at alternatives that exist today. This includes everything from mini PCs, to ancient business PCs being sold for peanuts, as well as more dedicated (ARM-based) hardware solutions.

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Reverse Engineering A Rock Bottom NES Clone

The NES was Nintendo’s smash hit console of the 1980s, the international version of their Japanese Famicom system. It wasn’t a particularly complex device, so it was the subject of many clones back in the day. More recently, it has enjoyed a new life thanks to “NES on a chip” systems. It’s one of these that [Poking Technology] has, real rock bottom for the console built into a cheap phone case.

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Classically-named Argus Robot Is Terminator Meets Tumbleweed

If you were making a multi-limbed symmetric nightmare of a robot, where else would you look for a name but Greek Mythology? The team at Duke University that came up with this particular multi-limbed creature had two obvious choices: name it for one of the Hundred-Handed giants, the Hecatoncheires, or lean on the fact that each limb has its own sensor and go for many-eyed Argus. Argus sounds better to a funding committee, so Argus it is.

Hecatoncheries would be a bit of a reach anyway, considering Argus only has 20 limbs in its current incarnation. It uses what the researchers are calling its ‘dynamic symmetry’ to get around– extending and retracting its many limbs to exert forces in any direction, it can bounce about like a beach ball on a windy day.

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Making A Zippy FDM Printer Out Of Wood

Generally, the frame and other structural parts of an FDM printer use steel or similar, but could you use wood instead for that truly artisan look? As [Mitsu Makes] demonstrates after half a year of work, you absolutely can, and it looks about as amazing as you might imagine.

Naturally, you cannot make everything out of wood – such as the linear rails and lead screws – and there is a fair bit of FDM-printed black PLA in there too, but the wood is both structural and decorative. The stained look does really add something. For the FDM-specific parts, the Voron 0 was taken as the base, including the bed. The motion system isn’t CoreXY but Cartesian for ease of construction and driving the axes, while also providing more torque due to the additional motors.

Since it’s more or less a Voron FDM printer and even has automatic bed leveling, it works basically perfectly after assembly and input shaping. Even if it’s not the most practical way to make your own FDM printer from parts, it definitely makes it look unique and would be the focal point of any printing farm.

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