batteries

50 Articles

Non-Replaceable Battery? Not If This Proposed EU Law Passes!

December 24, 2022 by 104 Comments

A disturbing trend in consumer electronics has been a steady disappearance of replaceable batteries on our devices. Finding a mobile phone with a swapable battery is a struggle, and many other devices follow the trend by sealing in a Li-Po cell. The result is an ever-shorter life for electronics, and a greater problem with devices going to recycling or worse still, landfill. Hope is at hand though, thanks to a proposed European Union law that would if passed make batteries in appliances “designed so that consumers can easily remove and replace them themselves“.

In case any readers in the rest of the world wonder what it has to do with them, the EU represents such a huge market that manufacturers can neither ignore it, nor in most cases afford to make separate EU and rest-of-world versions of their products. Thus if the EU requires something for sale in its territories, in most cases it becomes the de facto norm for anything designed to be sold worldwide. We’ve already seen this with the EU’s right to repair legislation, and while we have not doubt that manufacturers will do their best to impede this new law we don’t think they will ultimately prevail.

Via 9to5Mac.

Lithium-Ion Battery Circuitry Is Simple

October 10, 2022 by 55 Comments

By now, we’ve gone through LiIon handling basics and mechanics. When it comes to designing your circuit around a LiIon battery, I believe you could benefit from a cookbook with direct suggestions, too. Here, I’d like to give you a collection of LiIon recipes that worked well for me over the years.

I will be talking about single-series (1sXp) cell configurations, for a simple reason – multiple-series configurations are not something I consider myself as having worked extensively with. The single-series configurations alone will result in a fairly extensive writeup, but for those savvy in LiIon handling, I invite you to share your tips, tricks and observations in the comment section – last time, we had a fair few interesting points brought up!

The Friendly Neighborhood Charger

There’s a whole bunch of ways to charge the cells you’ve just added to your device – a wide variety of charger ICs and other solutions are at your disposal. I’d like to focus on one specific module that I believe it’s important you know more about.

You likely have seen the blue TP4056 boards around – they’re cheap and you’re one Aliexpress order away from owning a bunch, with a dozen boards going for only a few bucks. The TP4056 is a LiIon charger IC able to top up your cells at rate of up to 1 A. Many TP4056 boards have a protection circuit built in, which means that such a board can protect your LiIon cell from the external world, too. This board itself can be treated as a module; for over half a decade now, the PCB footprint has stayed the same, to the point where you can add a TP4056 board footprint onto your own PCBs if you need LiIon charging and protection. I do that a lot – it’s way easier, and even cheaper, than soldering the TP4056 and all its support components. Here’s a KiCad footprint if you’d like to do that too.

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Thank Magnesium For Water-Activated Batteries

October 4, 2022 by 16 Comments

Most of the batteries we use these days, whether rechargeable or not, are generally self-contained affairs. They come in a sealed package, with the anode, cathode, and electrolyte all wrapped up inside a stout plastic or metal casing. All the reactive chemicals stay inside.

However, a certain class of magnesium batteries are manufactured in a dry, unreactive state. To switch these batteries on, all you need to do is add water! Let’s take a look at these useful devices, and explore some of their applications.

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Lithium-Ion Batteries Are Easy To Find

October 3, 2022 by 43 Comments

In the first article, I’ve given you an overview of Lithium-Ion batteries and cells as building blocks for our projects, and described how hackers should treat their Lithium-Ion cells. But what if you don’t have any LiIon cells yet? Where do you get LiIon cells for your project?

Taking laptop batteries apart,  whether the regular 18650 or the modern pouch cell-based ones, remains a good avenue – many hackers take this road and the topic is extensively covered by a number of people. However, a 18650 cell might not fit your project size-wise, and thin batteries haven’t quite flooded the market yet. Let’s see what your options are beyond laptops. Continue reading “Lithium-Ion Batteries Are Easy To Find” →

Lithium-Ion Batteries Are Your Friends

September 6, 2022 by 56 Comments

Need some kind of battery for a project? You can always find a few Lithium-Ion (LiIon) batteries around! They’re in our phones, laptops, and a myriad other battery-powered things of all forms – as hackers, we will find ourselves working with them more and more. Lithium-Ion batteries are unmatched when it comes to energy capacity, ease of charging, and all the shapes and sizes you can get one in.

There’s also misconceptions about these batteries – bad advice floating around, fearmongering videos of devices ablaze, as well as mundane lack of understanding. Today, I’d like to provide a general overview of how to treat your LiIon batteries properly, making sure they serve you well long-term.

What’s A Battery? A Malleable Pile Of Cells

Lithium-Ion batteries are our friends. Now, there can’t be a proper friendship if you two don’t understand each other. Lithium-Ion batteries are tailored for human needs by the factory that produced them. As for us hackers, we’ll want to learn some things.

First thing to learn – a single LiIon “unit” is called a cell. An average laptop contains three or six Li-Ion cells, a phone will have one, a tablet will have from one to three. What we refer to as “battery” is typically one or multiple cells, together with protection circuitry, casing and a separate connector – most of the time all three of these, but not always. The typical voltage is 3.6 V or 3.7 V, with maximum voltage being 4.2 V – these are chemistry-defined, the same for most kinds of cells and almost always written on the cell. Continue reading “Lithium-Ion Batteries Are Your Friends” →

A Wireless Headphone Charger Without The Wireless

March 11, 2022 by 16 Comments

We’re all used to the idea of wireless charging, usually in the form of an induction coil on which a mobile phone or other appliance can be placed for a top-up. Not every battery-powered appliance has a built-in wireless charging coil though, meaning that despite the tech being available we all still have a jumble of wires.

[Sergio Costas] has a simple solution to conjuring wireless charging from thin air in his headphone stand, which conceals a set of charging contacts. It’s by no means a new idea and it might seem like an obvious hack, but it undeniably does away with the wires and we like it. After all, if it were that obvious, none of us would have that mess of chargers.

The headphones in question are a Bluetooth wireless pair, and the charging contacts have been brought out via a voltage regulator and a bridge rectifier to a pair of copper tapes along the sides of the headband. These mate with matching contacts in a 3D printed holder to which 12 VDC has been applied. Perhaps he’s just reinvented the springy contacts you’ll find on any cordless home phone, but it’s unquestionably a charger without wires.

Meanwhile if you have a conventional wireless charger, how do you know it’s working?

SV Seeker Is Recycling Batteries

April 14, 2021 by 38 Comments

SV Seeker is a home-made boat currently being built by [Doug Jackson] just north of Tulsa, Oklahoma. It’s a bit different than what you might imagine as a typical DIY boat, though. You see, Seeker is a 75 ft steel boat, intended to work as a research vessel. Doug and his crew proudly refer to Seeker as “The boat the internet built”, and he’s our kind of people. We’ve covered them before, the first time way back in 2013. Doug’s Youtube channel does double duty, both teaching the rest of us all the skills he’s learned while building, and also serving as the eventual user and repair manual for the boat.
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