Recycling Batteries With Bacteria

December 18, 2023 by Navarre Bartz 6 Comments

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 (LiNi_xMn_yCo_1-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.

Second Life UPS Mark II: A UPS For Low-Voltage DC Applications

December 17, 2023 by Maya Posch 17 Comments

When you have a whole stack of devices and appliances that all have an AC to DC adapter and which you’d like to put on an uninterruptable power supply (UPS), you could do the obvious thing and get an off-the-shelf UPS with myriad AC outputs. In the case of a 19″ rack this means wrangling a power strip or two and any combination of differently sized AC/DC adapters into the rack, with questionable efficiency and waste heat dumped into the rack. This is where a DC-only UPS like [Maciej Grela]’s Second Life UPS Mark II provides an interesting alternative.

At its core it’s a pretty simple concept: A single 400Watt power supply handles the AC/DC conversion from mains to 24 VDC, which feeds the battery charger as well as the outputs. These outputs include 5 VDC, 12 VDC and V_rail, with the latter being either the output from the PSU, or the battery voltage. In case of AC power failure, an LT4416 dual power path controller handles the switch-over from the PSU output to the internal batteries. In the article, [Maciej] covers how the buck modules for the 12 & 5 VDC rails were sized, along with the conversion of an old rack-mounted network switch into a UPS. Continue reading “Second Life UPS Mark II: A UPS For Low-Voltage DC Applications” →

Mods Turn Junk UPS Into A Long-Endurance Beast

December 15, 2023 by Dan Maloney 36 Comments

If you’ve got a so-called uninterruptible power supply (UPS) on your system, you’re probably painfully aware that the “uninterruptible” part has some pretty serious limits. Most consumer units are designed to provide power during a black out only long enough to gracefully shut down your system. But with a few hacks like these, you can stretch that time out and turn it into a long-endurance UPS.

As many good stories do, this one starts in the trash, where [MetaphysicalEngineer] spotted an APC home office-style UPS. It was clearly labeled “broken,” but that just turned out to be a dead battery. While he could have simply replaced it with a 12-volt sealed lead-acid battery, [Meta] knew that his computer setup would quickly deplete the standard battery. A little testing showed him that a car battery would extend the run time significantly, especially if he threw in some extra cooling for the onboard inverter.

His final design uses a marine deep-cycle battery in a plastic battery box with the UPS mounted on top. The vacated battery compartment made a great place to add a cooling fan, along with a clever circuit to turn it on only when the beeper on the UPS sounds, with a bonus volume control for the annoying sound. He also added accessories to the battery box top, including a voltmeter, a USB charger, and a switched 12-volt power outlet. And kudos for the liberal use of fuses in the build; things could get spicy otherwise. The video below shows the entire build along with all the testing. [MetaphysicalEngineer] managed to triple the estimated runtime for the load he’s trying to power, so it seems like a win to us.

If your needs run more toward keeping your networking gear running through a blackout, you might want to check out this inverter-less DC UPS.

Continue reading “Mods Turn Junk UPS Into A Long-Endurance Beast” →

Disposable Vape Batteries Turned USB Power Bank

December 14, 2023 by Tom Nardi 31 Comments

It’s another one of those fun quirks about our increasingly cyberpunk world — instead of cigarette butts littering our streets, you’re more likely to find disposable vaporizers that have run out of juice. Unfortunately, while the relatively harmless paper remnants of a cig would eventually just fall apart when exposed to the elements, these futuristic caltrops are not only potentially explosive thanks to their internal lithium-ion battery but aren’t going anywhere without some human intervention.

So do the environment and your parts bin a favor: pick them up and salvage their internal cells. As [N-Ender_3] shows with this build, it’s cheap and easy to turn the remnants of a few vapes into a useful USB power bank. In this case, the enclosure is 3D printed, which makes it particularly form-fitting, but you could just as easily pack the cells into something else if you’re not a fan of extruded plastic.

Continue reading “Disposable Vape Batteries Turned USB Power Bank” →

A 48 Volt Battery Pack With Carefully Balanced Cells

November 28, 2023 by Jenny List 60 Comments

Many readers will have at some time or another built their own lithium-ion battery packs, whether they are using tiny cells or the huge ones found in automotive packs. A popular choice it to salvage ubiquitous 18650 cylindrical cells, as [limpkin] has with this 48 volt pack. It’s based around an off-the-shelf kit aimed at the e-bike market, but it’s much more than a simple assembly job.

Faced with a hundred salvaged cells of unknown provenance, the first thing to do was ensure that they were all balanced and showed the same voltage. Some might do this the inefficient way by hooking each one up to a charger and a programmable load, but in this case a much more radical route was taken. A huge PCB was designed with sockets for all hundred cells, connected in parallel through individual series resistors. This allowed them to balance to a common voltage before being discharged to a safe voltage for assembly. Their individual ESRs were the measured, and the best performing examples were then spot-welded into the final 13s-6p final pack.

We all use lithium-ion batteries, but how many of us know how they work?

The Slow March Of Sodium-Ion Batteries To Compete With Lithium-Ion

November 26, 2023 by Maya Posch 56 Comments

The process of creating new battery chemistries that work better than existing types is a slow and arduous one. Not only does it know more failures than successes, it’s rare that a once successful type gets completely phased out, which is why today we’re using lead-acid, NiMH, alkaline, lithium, zinc-air, lithium-ion and a host of other battery types alongside each other. For one of the up-and-coming types in the form of sodium (Na)-based batteries the same struggles are true as it attempts to hit the right balance between anode, cathode and electrolyte properties. A pragmatic solution here involves Prussian Blue for the cathode and hard carbon for the anode, as is the case with Swedish Northvolt’s newly announced sodium-ion battery (SIB) which is sampling next year.

Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al. 2022) — Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al., 2022)

The story of SIBs goes back well over a decade, with a recent review article by Poonam Yadav and colleagues in Oxford Open Materials Science providing a good overview of the many types of anodes, cathodes and electrolytes which have been attempted and the results. One of the issues that prevents an SIB from directly using the carbon-based anodes employed with today’s lithium-ion batteries (LIB) is its much larger ionic radius that prevents intercalation without altering the carbon material to accept Na+ ions.

This is essentially where the hard carbon (HC) anode used by a number of SIB-producing companies comes into play, which has a far looser structure that does accept these ions and thus can be used with SIBs. The remaining challenges lie then with the electrolyte – which is where an organic form is the most successful – and the material for the sodium-containing cathode.

Although oxide forms and even sodium vanadium fluorophosphate (NVPF) are also being used, Prussian Blue analogs (PBAs) are attractive for being very low-cost and effective as cathode material once processed. An efficient way to process PB into fully sodiated and reduced Prussian White was demonstrated a few years ago, followed by successive studies backing up this assessment.

Although SIBs are seeing limited commercial use at this point, signs are that if it can be commercialized for the consumer market, it would have similar capacity as current LIBs, albeit with the potential to be cheaper, more durable and easier to recycle.