Battery Hacks

67 Articles

LiPo Replacement Keeps Portable Scanner In The Action

November 21, 2023 by 8 Comments

If there’s anything people hate more than being locked into a printer manufacturer’s replacement cartridges, it’s proprietary batteries. Cordless power tools are the obvious example in this space, but there are other devices that insist on crappy battery packs that are expensive to replace when they eventually die.

One such device is the Uniden Bearcat BC296D portable scanner that [Robert Guildig] found for a song at a thrift store, which he recently gave a custom LiPo battery upgrade. It came equipped with a nickel-cadmium battery pack, which even under the best of circumstances has a very limited battery life. Using regular AA batteries wasn’t an option, but luckily the space vacated by the OEM battery pack left a lot of room for mods. Those include a small module with BMS functions and a DC-DC converter, a 2,400 mAh 4.2 V LiPo pillow pack, and a new barrel connector for charging. With the BMS set for six volts and connected right to the old battery pack socket, the scanner can now run for seven hours on a one-hour charge. As a bonus, the LiPo pack should last a few times longer than the NiCd packs, and be pretty cheap to replace when it finally goes too. There’s a video after the hop with all the details.

If you’re looking at a similar battery replacement project, you might want to check out [Arya]’s guide to everything you need to know about lithium-ion circuitry.

Continue reading “LiPo Replacement Keeps Portable Scanner In The Action” →

Will Nickel-Hydrogen Cells Be The Energy Storage Holy Grail?

September 27, 2023 by 38 Comments

You may have heard us here remarking in the past, that if we had a pound, dollar, or Euro for every miracle battery technology story we heard that was going to change the world, we would surely be very wealthy by now. It’s certainly been the case that many such pronouncements refer to promising chemistries that turn out only to be realizable in a lab, but here there’s news of one with a bit of pedigree. Nickel hydrogen batteries have a long history of use in space, and there’s a startup producing them now for use on the ground. Could they deliver the energy storage Holy Grail?

The cathode in a nickel-hydrogen battery is formed by nickel hydroxide, and the anode is formed of hydrogen. If a gas as an anode sounds far fetched, we’re guessing that their structure is similar to the zinc-air battery, in which zinc hydroxide forms in a paste of powdered zinc, and works against oxygen from the air over a porous conductive support. What gives them their exciting potential is their ability to take more than 30,000 charge/discharge cycles, and their relative safety when compared to lithium ion cells. Hydrogen in a pressure vessel might not seem the safest of things to have around, but the chemistry is such that as the pressure increases it reacts to form water. The cost of the whole thing is reduced further as new catalysts have replaced the platinum used by NASA on spacecraft.

We really hope that these batteries will be a success, but as always we’ll wait and see before calling it. They may well be competing by then with the next generation of zinc-air cells.

Liquid Metal Battery Goes Into Production

August 12, 2023 by 89 Comments

The news is rife with claims of the next great thing in clean energy generation, but most of these technologies never make it to production. Whether that’s due to cost issues, production, or scalability, we’re often teased with industry breakthroughs that never come to fruition. Multi-layered solar panels, wave and tidal energy, and hydrogen fuel cells are all things that are real but can’t seem to break through and overtake other lower cost, simpler, and proven technologies. One that seems to be bucking this trend is the liquid metal battery, which startup Ambri is putting into service on the electrical grid next year.

With lithium ion battery installations running around $405 per kilowatt-hour, Ambri’s battery technology is already poised to be somewhat disruptive at a cost of about half that. The construction method is simpler than lithium as well, using molten metal electrodes and a molten salt electrolyte. Not only is this more durable, it’s also not flammable and is largely immune to degradation over time. The company’s testing results indicate that after 20 years the battery is expected to still retain 95% of its capacity. The only hitch in scaling this technology could be issues with sourcing antimony, one of the metals needed for this type of construction.

Even though Ambri can produce these batteries for $180 to $250 per kilowatt-hour, they need to get the costs down to about $20 for the technology to be cost-competitive with “base load” power plants (an outdated term in itself). They do project their costs to come down significantly and hit this mark by 2030, which would put electrical grids on course to be powered entirely by renewables. Liquid metal batteries aren’t the only nontraditional battery out there trying to solve this problem, though. Another promising interesting energy storage technology on the horizon is phase-change materials.

Minimizing Stress On A Coin Cell Battery

August 10, 2023 by 20 Comments

When it comes to powering tiny devices for a long time, coin cell batteries are the battery of choice for things like keyfobs, watches, and even some IoT devices. They’re inexpensive and compact and a great choice for very small electricity needs. Their major downside is that they have a relatively high internal resistance, meaning they can’t supply a lot of current for very long without decreasing the lifespan of the battery. This new integrated circuit uses a special DC-DC converter to get over that hurdle and extend the life of a coin cell significantly.

A typical DC-DC converter uses a rapidly switching transistor to regulate the energy flow through an inductor and capacitor, effectively stepping up or stepping down the voltage. Rather than relying on a single converter, this circuit uses a two-stage system. The first is a boost converter to step the voltage from the coin cell up to as much as 11 volts to charge a storage capacitor. The second is a buck converter which steps that voltage down when there is a high current demand. This causes less overall voltage drop on the battery meaning less stress for it and a longer operating life in the device.

There are a few other features of this circuit as well, including an optimizer which watches the behavior of the circuit and learns about the power demands being placed on it. That way, the storage capacitor is only charged up to its maximum capacity if the optimizer determines that much charge is needed. With all of these features a coin cell could last around seven times as long as one using more traditional circuitry. If you really need to get every last bit of energy from a battery, though, you can always use a joule thief.

A Deep Dive On Battery Life

July 28, 2023 by 12 Comments

There are all kinds of old wives’ tales surrounding proper battery use floating around in the popular culture. Things like needing to fully discharge a battery every so often, unplugging devices when they’re fully charged, or keeping batteries in the fridge are all examples that have some kernel of truth to them but often are improperly applied. If you really want to know the truth about a specific battery, its behavior, and its features, it helps to dig in and actually take some measurements directly like [Tyler] has done with a vast array of embedded batteries in IoT devices.

[Tyler] is a firmware engineer by trade, so he is deeply familiar with this type of small battery. Battery performance can change dramatically under all kinds of scenarios, most important among them being temperature. But even the same type of battery can behave differently to others that are otherwise identical, which is why it’s important to have metrics for the batteries themselves and be able to measure them to identify behaviors and possible problems. [Tyler] has a system of best practices in place for monitoring battery performance, especially after things like firmware upgrades since small software changes can often have a decent impact on battery performance.

While working with huge fleets of devices, [Tyler] outlines plenty of methods for working with batteries, deploying them, and making sure they’re working well for customers. A lot of it is extremely useful for other engineers looking to develop large-scale products like this but it’s also good knowledge to have for those of us rolling out our own one-off projects that will operate under battery power. After all, not caring for one’s lithium batteries can have disastrous consequences.

Harvesting Rechargeable Batteries From Single-Use Devices

June 7, 2023 by 63 Comments

The price of lithium batteries has plummeted in recent years as various manufacturers scale up production and other construction and process improvements are found. This is a good thing if you’re an EV manufacturer, but can be problematic if you’re managing something like a landfill and find that the price has fallen so low that rechargeable lithium batteries are showing up in the waste stream in single-use devices. Unlike alkaline batteries, these batteries can explode if not handled properly, meaning that steps to make sure they’re disposed of properly are much more important. [Becky] found these batteries in single-use disposable vape pens and so set about putting them to better use rather than simply throwing them away.

While she doesn’t use the devices herself, she was able to source a bunch of used ones locally from various buy-nothing groups. Disassembling the small vape pens is fairly straightforward, but care needed to be taken to avoid contacting some of the chemical residue inside of the devices. After cleaning the batteries, most of the rest of the device is discarded. The batteries are small but capable and made of various lithium chemistries, which means that most need support from a charging circuit before being used in any other projects. Some of the larger units do have charging circuitry, though, but often it’s little more than a few transistors which means that it might be best for peace-of-mind to deploy a trusted charging solution anyway.

While we have seen projects repurposing 18650 cells from various battery packs like power tools and older laptops, it’s not too far of a leap to find out that the same theory can be applied to these smaller cells. The only truly surprising thing is that these batteries are included in single-use devices at all, and perhaps also that there are few or no regulations limiting the sale of devices with lithium batteries that are clearly intended to be thrown away when they really should be getting recycled.

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A series of food items along the bottom of the frame including an unidentified grey block, an almond, a food supplement capsule, a square of seaweed, a square of beeswax, and a crumpled up piece of gold foil. At the top of the image is a fully assembled battery with electrodes sticking out the ends of a block of beeswax and a half finished battery with the nori separator visible.

A Delicious Advancement In Battery Tech

April 22, 2023 by 2 Comments

Electronics have been sent to some pretty extreme environments, but inside a living host is a particularly tricky set of conditions, especially if you don’t want to damage the organism ingesting the equipment. One step in that direction could be an edible battery cell. (via Electrek)

Developed by scientists at the Istituto Italiano di Tecnologia, this new cell is made from food additives and ingredients to skirt any nasty side effects one might experience from ingesting a less palatable battery chemistry like NiCd. A riboflavin anode is coupled with a quercetin cathode, both with activated carbon to increase conductivity. Encapsulated in beeswax and with a separator made of nori algae, the battery is completely non-toxic.

The cell generates a modest 0.65V with a max sustained current of 48 µA for 12 min, but it shows promise as a power source for ingestible medical sensors, even if it won’t be powering your next mobile Raspberry Pi project. This isn’t the first time we’ve seen edible electronics; check out this screaming chocolate rabbit or robots made of candy.