Ultimate Power: Lithium-Ion Batteries In Series

At some point, the 3.6 V of a single lithium ion battery just won’t do, and you’ll absolutely want to stack LiIon cells in series. When you need high power, you’ve either got to increase voltage or current, and currents above say 10 A require significantly beefed up components. This is how you’re able to charge your laptop from your USB-C powerbank, for instance.

Or maybe you just need higher voltages, and don’t feel like using a step-up converter, which brings along with it some level of inefficiency. Whatever your reasons, it’s time to put some cells into series. Continue reading “Ultimate Power: Lithium-Ion Batteries In Series”

Showing a USB-C tester running the DingoCharge script, charging a battery pack at 7V. To the right is a battery pack being charged, and a USB-C charger doing the charging.

Use USB-C Chargers To Top Up Li-Ion Packs With This Hack

In USB-C Power Delivery (PD) standard, the PPS (Programmable Power Supply) mode is an optional mode that lets you request a non-standard voltage from a charger, with the ability to set a current limit of your choice, too. Having learned this, [Jason] from [Rip It Apart] decided to investigate — could this feature be used for charging Li-Ion battery packs, which need the voltage and current to vary in a specific way throughout the charging process? Turns out, the answer is a resounding “yes”, and thanks to a USB-C tester that’s programmable using Lua scripts, [Jason] shows us how we can use a PPS-capable USB-C charger for topping up our Li-Ion battery packs, in a project named DingoCharge.

The wonderful write-up answers every question you have, starting with a safety disclaimer, and going through everything you might want to know. The GitHub repo hosts not only code but also full installation and usage instructions.

DingoCharge handles more than just Li-Ion batteries — this ought to work with LiFePO4 and lithium titanate batteries, too.  [Jason] has been working on Ni-MH and lead-acid support. You can even connect an analog output thermal sensor and have the tester limit the charge process depending on the temperature, showing just how fully-featured a solution the DingoCharge project is.

The amount of effort put into polishing this project is impressive, and now it’s out there for us to take advantage of; all you need is a PPS-capable PSU and a supported USB-C tester. If your charger’s PPS is limited by 11V, as many are, you’ll only be able to fully charge 2S packs with it – that said, this is a marked improvement over many Li-Ion solutions we’ve seen. Don’t have a Li-Ion pack? Build one out of smartphone cells! Make sure your pack has a balancing circuit, of course, since this charger can’t provide any, and all will be good. Still looking to get into Li-Ion batteries? We have a three-part guide, from basics to mechanics and electronics!

Potential Contenders For Battery Supremacy

Lithium ion batteries have been a revolutionary technology. Their high energy and power density has made the electric car a practical reality, enabled grid storage for renewable energy, and put powerful computers in the palm of the hand. However, if there’s one thing humanity is known for, it’s always wanting more.

Potential contenders for the title of ultimate battery technology are out there, but it will take a major shift to dethrone lithium-ion from the top of the tree.

Dominant For Good Reason

Lithium-ion batteries were first developed by Stanley Whittingham, working at Exxon, who were looking to diversify away from oil in the midst of the major energy crises of the 1970s. Over the years, the technology was developed further, with work by John Goodenough (a superb hacker name if we’ve ever heard one) and Akira Yoshino increasing performance with improved cathode and anode materials. Commercialization was first achieved by Keizaburo Tozawa, working at Sony to develop a better battery for the company’s line of camcorders. Continue reading “Potential Contenders For Battery Supremacy”

The Science Behind Lithium Cell Characteristics And Safety

To describe the constraints on developing consumer battery technology as ‘challenging’ is an enormous understatement. The ideal rechargeable battery has conflicting properties – it has to store large amounts of energy, safely release or absorb large amounts of it on demand, and must be unable to release that energy upon failure. It also has to be cheap, nontoxic, lightweight, and scalable.

As a result, consumer battery technologies represent a compromise between competing goals. Modern rechargeable lithium batteries are no exception, although overall they are a marvel of engineering. Mobile technology would not be anywhere near as good as it is today without them. We’re not saying you cannot have cellphones based on lead-acid batteries (in fact the Motorola 2600 ‘Bag Phone’ was one), but you had better have large pockets. Also a stout belt or… some type of harness? It turns out lead is heavy.

The Motorola 2600 ‘bag phone’, with a lead-acid battery. Image CC-BY-SA 3.0 source: Trent021

Rechargeable lithium cells have evolved tremendously over the years since their commercial release in 1991. Early on in their development, small grains plated with lithium metal were used, which had several disadvantages including loss of cell capacity over time, internal short circuits, and fairly high levels of heat generation. To solve these problems, there were two main approaches: the use of polymer electrolytes, and the use of graphite electrodes to contain the lithium ions rather than use lithium metal. From these two approaches, lithium-ion (Li-ion) and lithium-polymer (Li-Po) cells were developed (Vincent, 2009, p. 163). Since then, many different chemistries have been developed.

Continue reading “The Science Behind Lithium Cell Characteristics And Safety”

Semisolid Lithium Ion Batteries Promise Better Cars, Solar

Lithium-ion batteries make possible smaller and lighter electronics. Unfortunately, they are also costly to produce. In a conventional lithium-ion battery, many thin layers create the finished product much like filo dough in baklava. A startup company called 24M thinks they have the answer to making less expensive lithium-ion batteries: a semisolid electrode made by mixing powders and liquid to form an electrolyte goo.

Not only will the batteries be cheaper and faster to create, but the cost of the factory will be less. Currently, 24M has a pilot manufacturing line, but by 2020 they expect to scale to produce batteries that cost less than $100 per kilowatt hour (today’s costs are about $200 to $250 for conventional batteries). Under $100, the batteries become competitive with the cost of internal combustion engines, according to the article.

Continue reading “Semisolid Lithium Ion Batteries Promise Better Cars, Solar”

Hacklet 39: Battery Power

3296371398740598106[robin] has a Red Camera (lucky!), an absurdly expensive digital video camera. As you would expect the batteries are also absurdly expensive. What’s the solution? Battery packs from cordless drills.

Cordless drills are interesting pieces of tech that can be easily repurposed; there are huge battery packs in them, big, beefy motors, and enough hardware to build an Automatic Cat Feeder or a motorized bicycle.

What if those old Makita batteries don’t charge? That usually means only one or two cells are dead, not the whole pack. Free LiIon cells, but you need to charge them. Here’s a single cell charger/boost converter that will do the trick.


A problem faced by amateur radio operators around the world is the lack of commercial power. Plugging a portable shack into a wall will work, but for uninterrupted power car batteries are everywhere. How do you combine wall power and car batteries for the best of both worlds? With an In-line battery backup module.

9k=All of the projects above rely on charging a battery through wall power, and sometimes even that is impossible. Solar is where we’re headed, with solar LiPo chargers, and solar LiFe chargers. That’s more than enough to keep a smartphone charged, but if you want to go completely off the grid, you’re going to need something bigger.

[Michel] has been off the power grid 80% of the time since he installed his home PV system a few years ago. How’s he doing it? A literal ton of batteries, huge chargers, and a 5kW inverter.


The Ins And Outs Of Lithium-based Battery Packs


So, you’ve got your awesome project built and are ready to take it on the go, but how are you going to power it? You could use a couple alkaline cells or perhaps swipe a Litihium battery pack from some infrequently used portable device – however before you do that, why not check out what [Lady Ada] has to say on the subject?

The detailed tutorial on her site discusses the different types of Lithium-based batteries and their form factors, as well as the strengths and weaknesses of each type. Voltage ratings are covered, as well as why it is important to choose a Lithium battery pack that fits the task at hand. The dangers of improperly handling batteries are clearly noted, highlighting the importance of selecting a proper charger and resisting the urge to ever wire Lithium batteries together to increase capacity.

While the bulk of the information presented is nothing new to most of our readers, it’s definitely a worthwhile read for those just starting to use Lithium battery technology in their projects.