Battle Born LFP Battery Melts With New Problem

January 16, 2026 by Maya Posch 23 Comments

Following up on user-reported cases of Battle Born LiFePO4 batteries displaying very hot positive terminals, [Will Prowse] decided to buy a brand new one of these LFP batteries for some controlled cycle testing.

Starting with 30 cycles with a charging current of 49 A and a discharge current of 99 A, this put it well within the 100 A continuous rating for the battery. There is also a surge current rating of 200 A for thirty seconds, but that was not tested here.

What’s interesting about the results here is that instead of the positive terminal getting visibly discolored as with the previous cases that we reported on, [Will] saw severe thermal effects on the side of the negative terminal to the point where the plastic enclosure was deforming due to severe internal heating.

During testing, the first two charge-discharge cycles showed full capacity, but after that the measured capacity became extremely erratic until the battery kept disconnecting randomly. After letting the battery cool down and trying again with 80 A discharge current the negative terminal side of the enclosure began to melt, which was a good hint to stop testing. After this the battery also couldn’t be charged any more by [Will]’s equipment, probably due to the sketchy contact inside the battery.

It’s clear that the plastic spacer inside the terminal bus bar was once again the primary cause, starting a cascade which resulted in not only the enclosure beginning to char and melt, but with heat damage visible throughout the battery. Considering that the battery was used as specified, without pushing its limits, it seems clear that nobody should be using these batteries for anything until Battle Born fixes what appears to be the sketchiest terminal and bus bar design ever seen in a high-current battery.

Continue reading “Battle Born LFP Battery Melts With New Problem” →

Looking At A Real Fake Raspberry Pi RP2040 Board

January 15, 2026 by Maya Posch 19 Comments

Since the RP2040 microcontroller is available as a stand-alone component, it’s easy enough for third parties to churn out their own variations — or outright clones of — the Raspberry Pi Pico. Thus we end up with for example AliExpress sellers offering their own versions that can be significantly cheaper than the genuine article. The ones that [electronupdate] obtained for a test and decapping session cost just $2.25 a pop.

As can be seen in the top image, the board from AliExpress misses the Raspberry Pi logo on the silkscreen for obvious reasons, but otherwise appears to feature an identical component layout. The QSPI Flash IC is marked on the die as BY250156FS, identifying it as a Boya part.

Niggles about flash ROM quality aside, what’s perhaps most interesting about this teardown is what eagle-eyed commentators spotted on the die shot of the RP2040. Although on the MCU the laser markings identify the RP2040 as a B2 stepping, the die clearly identifies it as an ‘RP2 B0’ part, meaning B0 stepping. This can be problematic when you try to use the USB functionality due to hardware USB bugs in the B0 and B1 steppings.

As they say, caveat emptor.

Continue reading “Looking At A Real Fake Raspberry Pi RP2040 Board” →

DIY Grid Dip Meter Teardown

January 7, 2026 by Al Williams 5 Comments

You don’t see them much anymore, but there was a time when any hobbyist who dealt with RF probably had a grid dip meter. The idea was to have an oscillator and measure the grid current as it coupled to external circuits. At resonance, the grid current would go down or dip, hence the name. In the hands of someone who knew how to use it, the meter could measure inductance, capacitance, tuned circuits, antennas, and more. [Thomas] takes a peek inside a homebrew unit from the 1950s in a recent video you can see below.

These meters often have a few things in common. They usually have a plug-in coil near the top and a big tuning capacitor. Of course, there’s also a meter. You have to pick the right coil for the frequency of interest, which both sets the oscillator frequency range and couples to the circuit under test.

Continue reading “DIY Grid Dip Meter Teardown” →

Teardown Of Boeing 777 Cabin Pressure Control System

January 3, 2026 by Maya Posch 24 Comments

Modern passenger airliners are essentially tubes-with-wings, they just happen to be tubes that are stuffed full with fancy electronics. Some of the most important of these are related to keeping the bits of the tube with humans inside it at temperatures and pressures that keeps them alive and happy. Case in point the Boeing 777, of which [Michel] of Le Labo de Michel on YouTube recently obtained the Cabin Pressure Control System (CPCS) for a teardown.

The crucial parts on the system are the two Nord-Micro C0002 piezo resistive pressure transducers, which measure the pressure inside the aircraft. These sensors, one of which is marked as ‘backup’, are read out by multiple ADCs connected to a couple of FPGAs. The system further has an ARINC 429 transceiver, for communicating with the other avionics components. Naturally the multiple PCBs are conformally coated and with vibration-proof interconnects.

Although it may seem like a lot of hardware just to measure air pressure with, this kind of hardware is meant to work without errors over the span of years, meaning significant amounts of redundancy and error checking has to be built-in. Tragic accidents such as Helios Airways Flight 522 involving a 737-300 highlight the importance of these systems. Although in that case human error had disabled the cabin pressurization, it shows just how hard it can be to detect hypoxia before it is too late.

Continue reading “Teardown Of Boeing 777 Cabin Pressure Control System” →

Born To Burn: The Battle Born LFP Battery

December 25, 2025 by Maya Posch 39 Comments

Would you feel confident in buying US-made LiFePO₄ (LFP) batteries? While the answer here is generally expected to be ‘yes’, especially compared to getting an unbranded LFP battery off eBay from a random seller, the outcome may not be that different. Case in point the 100 Ah, 12 VDC LFP Battle Born battery that [Will Prowse] took a look at to see why its positive terminal gets positively crispy.

Battle Born battery positive terminal. (Credit: Will Prowse, YouTube)

Once the lid was cut off, it’s easy to see what the problem is: the positive terminal is only loosely attached to the bus bar, leading to extremely poor contact. It also appears that there’s a plastic spacer which has properly melted already in this well-used battery that [Will] obtained from a viewer.

This overheating issue with Battle Born batteries has been reported for years now, which makes it a great idea to take a good look at any Battle Born LFP batteries you may have kicking around, as they may be plagued by the same design flaw. Trying to make use of the manufacturer’s warranty could be complicated based on the commentators in the DIY Solar Forum thread, as Battle Born likes to claim that the overheating issue is an external problem and not a design flaw.

Either way, it looks like an incredibly sketchy way to design a battery terminal on an LFP battery that is supposed to surge 100+A. [Will] is requesting that anyone affected posts details in the forum or similar to get all information together, as he looks to push Battle Born on this issue.

What makes this issue worse is that shortly after releasing that first video, Battle Born responded to some concerned customers with a response that claims that their terminal design is a ‘thermal fail-safe’, but as can be seen in [Will]’s follow-up video, it absolutely doesn’t look like one.

Continue reading “Born To Burn: The Battle Born LFP Battery” →

Tearing Down Walmart’s $12 Keychain Camera

December 15, 2025 by Lewin Day 47 Comments

Keychain cameras are rarely good. However, in the case of Walmart’s current offering, it might be worse than it’s supposed to be. [FoxTailWhipz] bought the Vivitar-branded device and set about investigating its claim that it could deliver high-resolution photos.

The Vivatar Retro Keychain Camera costs $12.88, and wears “FULL HD” and “14MP” branding on the packaging. It’s actually built by Sakar International, a company that manufactures products for other brands to license. Outside of the branding, though, [FoxTailWhipz] figured the resolution claims were likely misleading. Taking photos quickly showed this was the case, as whatever setting was used, the photos would always come out at 640 x 480, or roughly 0.3 megapixels. He thus decided a teardown would be the best way to determine what was going on inside. You can see it all in the video below.

Pulling the device apart was easy, revealing that the screen and battery are simply attached to the PCB with double-sided tape. With the board removed from the case, the sensor and lens module are visible, with the model number printed on the flex cable. The sensor datasheet tells you what you need to know. It’s a 2-megapixel sensor, capable of resolutions up to 1632 x 1212. The camera firmware itself seems to not even use the full resolution, since it only outputs images at 640 x 480.

It’s not that surprising that an ultra-cheap keychain camera doesn’t meet the outrageous specs on the box. At the same time, it’s sad to see major retailers selling products that can’t do what they say on the tin. We see this problem a lot, in everything from network cables to oscilloscopes.

Continue reading “Tearing Down Walmart’s $12 Keychain Camera” →

Mass Spectrometer Tear Down

December 15, 2025 by Al Williams 7 Comments

If you have ever thought, “I wish I could have a mass spectrometer at home,” then we aren’t very surprised you are reading Hackaday. [Thomas Scherrer] somehow acquired a broken Brucker Microflex LT Mass Spectrometer, and while it was clearly not working, it promised to be a fun teardown, as you can see in the first part of the video below.

Inside are lasers and definitely some high voltages floating around. This appears to be an industrial unit, but it has a great design for service. Many of the panels are removable without tools.

Continue reading “Mass Spectrometer Tear Down” →