battery

400 Articles

Bioelectronic implants with size reference

Batteries Not Included: Navigating The Implants Of Tomorrow

November 19, 2024 by 19 Comments

Tinkerers and tech enthusiasts, brace yourselves: the frontier of biohacking has just expanded. Picture implantable medical devices that don’t need batteries—no more surgeries for replacements or bulky contraptions. Though not all new (see below), ChemistryWorld recently shed new light on these innovations. It’s as exciting as it is unnerving; we, as hackers, know too well that tech and biology blend a fine ethical line. Realising our bodies can be hacked both tickles our excitement and unsettlement, posing deeper questions about human-machine integration.

Since the first pacemaker hit the scene in 1958, powered by rechargeable nickel-cadmium batteries and induction coils, progress has been steady but bound by battery limitations. Now, researchers like Jacob Robinson from Rice University are flipping the script, moving to designs that harvest energy from within. Whether through mechanical heartbeats or lung inflation, these implants are shifting to a network of energy-harvesting nodes.

From triboelectric nanogenerators made of flexible, biodegradable materials to piezoelectric devices tapping body motion is quite a leap. John Rogers at Northwestern University points out that the real challenge is balancing power extraction without harming the body’s natural function. Energy isn’t free-flowing; overharvesting could strain or damage organs. A topic we also addressed in April of this year.

As we edge toward battery-free implants, these breakthroughs could redefine biomedical tech. A good start on diving into this paradigm shift and past innovations is this article from 2023. It’ll get you on track of some prior innovations in this field. Happy tinkering, and: stay critical! For we hackers know that there’s an alternative use for everything!

Disposable Vape Batteries Power EBike

November 7, 2024 by 15 Comments

There are a lot of things that get landfilled that have some marginal value, but generally if there’s not a huge amount of money to be made recycling things they won’t get recycled. It might not be surprising to most that this is true of almost all plastic, a substantial portion of glass, and even a lot of paper and metals, but what might come as a shock is that plenty of rechargeable lithium batteries are included in this list as well. It’s cheaper to build lithium batteries into one-time-use items like disposable vape pens and just throw them out after one (or less than one) charge cycle, but if you have some spare time these batteries are plenty useful.

[Chris Doel] found over a hundred disposable vape pens after a local music festival and collected them all to build into a battery powerful enough for an ebike. Granted, this involves a lot of work disassembling each vape which is full of some fairly toxic compounds and which also generally tend to have some sensitive electronics, but once each pen was disassembled the real work of building a battery gets going. He starts with testing each cell and charging them to the same voltage, grouping cells with similar internal resistances. From there he assembles them into a 48V pack with a battery management system and custom 3D printed cell holders to accommodate the wide range of cell sizes. A 3D printed enclosure with charge/discharge ports, a power switch, and a status display round out the build.

With the battery bank completed he straps it to his existing ebike and hits the trails, easily traveling 20 miles with barely any pedal input. These cells are only rated for 300 charge-discharge cycles which is on par for plenty of similar 18650 cells, making this an impressive build for essentially free materials minus the costs of filament, a few parts, and the sweat equity that went into sourcing the cells. If you want to take an ebike to the next level of low-cost, we’d recommend pairing this battery with the drivetrain from the Spin Cycle.

Thanks to [Anton] for the tip!

The FNIRSI HRM-10 Internal Resistance Meter

October 17, 2024 by 16 Comments

Occasionally, we find fun new electronic instruments in the wild and can’t resist sharing them with our readers. The item in question is the FNIRSI HRM-10 Internal resistance meter, which we show here being reviewed by [JohnAudioTech].

So what does it do, and why would you want one? The device is designed to measure batteries so you can quickly determine their health. Its operating principle also allows it to do a decent job of measuring low-resistance parts, which is not necessarily as easy to achieve with the garden variety multimeter, especially the low-end ones. We reckon it would be useful in the field for checking the resistance of switches and relays, possibly in automotive or industrial applications. The four-pin connector is needed because there are two wires per probe, making a Kelvin (also known as four-wire) connection.

Likely, the operating principle is to apply a varying load to the battery under test and then measure the voltage drop. The slope of the voltage sag vs load is a reasonable estimate of the resistance of the source, at least for the applied voltage range. The Kelvin connection uses one pair of wires to apply the test current from a relatively low-impedance source and the second pair to measure the voltage with a high input impedance. That way, the resistance of the probe wires can be calibrated out, giving a much more accurate measurement. Many lab-grade measurement equipment works this way.

Circling back to the HRM-10, [John] notes that it also supports limit testing, making it a helpful gauging tool for the workbench when sorting through many batteries. Data logging and the ability to upload to a computer completes the feature set, which is quite typical for this level of product now. Gone are the days of keeping a manual logbook next to the instrument stack and writing everything down by hand!

We’ve touched on measuring battery internal resistance before, but it was a while ago. Regarding Kelvin connections, here’s a quick guide and a hack upgrading a cheap LCR to support 4-wire probes.

Continue reading “The FNIRSI HRM-10 Internal Resistance Meter” →

Universal Power Bank Customized To Your Liking

August 31, 2024 by 10 Comments

One of the most troubling trends of almost every modern consumer product that uses electricity is that the software that controls the product is likely to be proprietary and closed-source, which could be doing (or not doing) any number of things that its owner has no control over. Whether it’s a computer, kitchen appliance, or even a device that handles the electricity directly, it’s fairly rare to find something with software that’s open and customizable. That’s why [Traditional-Code9728] is working on a power bank with an open-source firmware.

From a hardware perspective the power bank is fairly open as well, with a number of options for connecting this device to anything else that might need power. It sports a bidirectional USB-C port as well as a DC barrel plug, either of which can either charge other devices or receive energy to charge its own battery. These ports can also accept energy from a solar panel and have MPPT built in. There’s also dual USB-A ports which can provide anywhere from five to 12 volts at 25 watts, and a color screen which shows the current status of the device.

While this is a prototype device, it’s still actively being worked on. Some future planned upgrades to the power bank include a slimmer design, charge limiting features to improve battery life, and more fine-tuned control of the output voltage and current on the USB-C port. With all of the software being open-source, as well as the circuit diagram and 3D printing files, it could find itself in plenty of applications as well. This power bank also stays under the energy limits for flying on most commercial airlines as well, but if you don’t plan on taking your power bank on an airplane then you might want to try out this 2000-watt monster instead.

Hardware Reuse: The PMG001 Integrated Power Management Module

August 27, 2024 by 15 Comments

Battery management is a tedious but necessary problem that becomes more of a hassle with lithium-ion technology. As we’re all very aware, such batteries need a bit of care to be utilized safely, and as such, a huge plethora of ICs are available to perform the relevant duties. Hackaday.IO user [Erik] clearly spent some time dropping down the same old set of ICs to manage a battery in their applications, so they created a drop-in castellated PCB to manage all this.

Continue reading “Hardware Reuse: The PMG001 Integrated Power Management Module” →

Ryobi Battery Pack Gives Up Its Secrets Before Giving Up The Ghost

August 14, 2024 by 44 Comments

Remember when dead batteries were something you’d just toss in the trash? Those days are long gone, thankfully, and rechargeable battery packs have put powerful cordless tools in the palms of our hands. But when those battery packs go bad, replacing them becomes an expensive proposition. And that’s a great excuse to pop a pack open and see what’s happening inside.

The battery pack in question found its way to [Don]’s bench by blinking some error codes and refusing to charge. Popping it open, he found a surprisingly packed PCB on top of the lithium cells, presumably the battery management system judging by the part numbers on some of the chips. There are a lot of test points along with some tempting headers, including one that gave up some serial data when the battery’s test button was pressed. The data isn’t encrypted, but it is somewhat cryptic, and didn’t give [Don] much help. Moving on to the test points, [Don] was able to measure the voltage of each battery in the series string. He also identified test pads that disable individual cells, at least judging by the serial output, which could be diagnostically interesting.  [Don]’s reverse engineering work is now focused on the charge controller chip, which he’s looking at through its I2C port. He seems to have done quite a bit of work capturing output and trying to square it with the chip’s datasheet, but he’s having trouble decoding it.

This would be a great place for the Hackaday community to pitch in so he can perhaps get this battery unbricked. We have to admit feeling a wee bit responsible for this, since [Don] reports that it was our article on reverse engineering a cheap security camera that inspired him to dig into this, so we’d love to get him some help.

Magnesium And Copper Makes An Emergency Flashlight

August 8, 2024 by 17 Comments

Many of us store a flashlight around the house for use in emergency situations. Usually, regular alkaline batteries are fine for this task, as they’ll last a good few years, and you remember to swap them out from time to time. Alternatively, you can make one that lasts virtually indefinitely in storage, and uses some simple chemistry, as [JGJMatt] demonstrates.

The flashlight uses 3D printing to create a custom battery using magnesium and copper as the anode and cathode respectively. Copper tape is wound around a rectangular part to create several cathode plates, while magnesium ribbon is affixed to create the anodes. Cotton wool is then stuffed into the 3D-printed battery housing to serve as a storage medium for the electrolyte—in this case, plain tap water.

The custom battery is paired with a simple LED flashlight circuit in its own 3D-printed housing. The idea is that when a blackout strikes, you can assemble the LED flashlight with your custom battery, and then soak it in water. This will activate the battery, producing around 4.5 V and 20 mA to light the LED.

It’s by no means going to be a bright flashlight, and realistically, it’s probably less reliable than just keeping a a regular battery-powered example around. Particularly given the possibility of your homebrew battery corroding over the years unless it’s kept meticulously dry. But that’s not to say that water-activated batteries don’t have their applications, and anyway it’s a fun project that shows how simple batteries really are at their basic level. Consider it as a useful teaching project if you have children interested in science and electricity!