Battery Management Module Hacked For Lithium-Iron Battery Bank

September 14, 2017 by Dan Maloney 37 Comments

In a departure from his usual repair and tear down fare, [Kerry Wong] has set out on a long-term project — building a whole-house battery bank. From the first look at the project, this will be one to watch.

To be fair, [Kerry] gave us a tease at this project a few months back with his DIY spot welder for battery tabs. Since then, he appears to have made a few crucial design decisions, not least of which is battery chemistry. Most battery banks designed for an inverter with enough power to run household appliances rely on lead-acid batteries, although lithium-ion has certainly made some inroads. [Kerry] is looking to run a fairly small 1000-watt inverter, and his analysis led him to lithium-iron cells. The video below shows what happens when an eBay pack of 80 32650 LiFePo4 cells meets his spot welder. But then the problem becomes one of sourcing a battery management system that’s up to the charge and discharge specs of his 4s battery pack. We won’t spoil the surprise for you, but suffice it to say that [Kerry] really lucked out that only minimal modifications were needed for his $9 off-the-shelf BMS module.

We’re looking forward to seeing where this build goes, not least because we’d like to build something similar too. For a more traditional AGM-based battery bank, check out this nicely-engineered solar-charged system.

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This Electric Longboard Collapses For Air Travel

September 8, 2017 by Dan Maloney 26 Comments

How do you manage to get an electric off-road longboard past TSA and onto an international flight? Simple — make it a collapsible longboard that fits into a carry-on bag.

The mechanical and electrical feats accomplished by [transistor-man] may not be the most impressive parts of this hack. We’re pretty impressed by the build, starting as it did with the big knobby tires and front truck from an unused mountain board and the hub motor from a hoverboard, turning this into a trike. The incredible shrinking chassis comes courtesy of a couple of stout drawer slides and cam locks to keep it locked in place; collapsed, the board fits in a carry on bag. Expanded, it runs like a dream, as the video below shows.

But we think the really interesting part of this hack is the social engineering [transistor-man] did to ensure that the authorities wouldn’t ground his creation for electrical reasons. It seems current rules limit how big a battery can be and how many of them can be brought on a flight, so there was a lot of battery finagling before his creation could fly.

Electric longboards look like a real kick, whether they be all-aluminum or all-plastic, or even all-LEGO. This one, which went from concept to complete a week and a half before the flight, really raises the bar.

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Engage Tinfoil Hat: Samsung Note 7 Battery Theory

October 24, 2016 by Mike Szczys 144 Comments

For the most part I believe things are as they seem. But every once in a while I begin to look at notable technology happenings from a different angle. What if things are not like they seem? This is conspiracy theory territory, and I want to be very clear about this: what follows is completely fictitious and not based on fact. At least, I haven’t tried to base it on facts surrounding the current events. But perhaps you can. What if there’s more to the battery fires in Samsung’s Galaxy Note 7 phones?

I have a plausible theory, won’t you don your tinfoil hat and follow me down this rabbit hole?

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Tour De Force Battery Hacking

September 3, 2016 by Elliot Williams 23 Comments

Lithium-Ion batteries are finicky little beasts. They can’t be overcharged, overdischarged, overheated, or even looked at funny without bursting into flames. Inside any laptop battery pack, a battery charge controller keeps watch over all the little cells, and prevents them from getting damaged.

Of course, any “smart” device will sometimes make the wrong choices, and then it’s up to us to dig inside its brains and fix it. When [Viktor] got a perfectly good battery pack with a controller that refused to charge the batteries, he started off on what would become an epic journey into battery controllers, and the result is not just a fixed battery, but a controller-reprogramming tool, software, and three reversed controller chips so far.

Battery controller chips speak SMBus, and [Viktor] started out by building a USB-SMBus tool. It’s a clever use of a cheap eBay development board for a Cypress CY7C68013A USB microcontroller. Flashed with [Viktor]’s firmware and running his software on the host computer, a SMBus scan is child’s play.

The rest of the story is good old-fashioned hacking: looking for datasheets, reading industry powerpoints, taking wild guesses, googling for passwords, and toggling the no-connect pins while booting the controllers up. We’re not going to argue with results: the bq8030, R2J240, and M37512 controllers have all given up their secrets, and tools to program them have been integrated into [Viktor]’s SMBusb tool.

In short, this is one of the nicest hard-core hacks we’ve seen in a while. Kudos [Viktor]! And thanks for the SMBus tool.

Ugly DIY Portable Soldering Iron

July 26, 2016 by Al Williams 6 Comments

If you’ve ever wanted a battery-operated soldering iron and you just can’t stand the thought of buying one, you might check out the video below from [Just5mins]. In it, he takes a candy tube, some scrap materials, a lithium ion battery, a nichrome wire, a USB charger, and a switch and turns it into an apparently practical soldering iron.

Paradoxically, [Just5mins] used a soldering iron to build this one, so it probably can’t be your only soldering iron, although we suppose you could figure something out in a pinch. Maybe in rep-rap style, make a poor quality one with no soldering and use it to solder up the next one.

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Semisolid Lithium Ion Batteries Promise Better Cars, Solar

July 23, 2016 by Al Williams 28 Comments

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.

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Safely Creating A Li-Ion Pack From Phone Cells

June 2, 2016 by Jenny List 47 Comments

[Glen], at Maker Space Newcastle Upon Tyne, is refreshingly honest. As he puts it, he’s too cheap to buy a proper battery.

He needed a 1AH battery pack to power his quadcopter controller and FPV headset, and since inadequate discharge warnings had led him to damage lithium polymer cells with these devices, he wanted his pack to use lithium-ion cells. His requirements were that the cells be as cheap, lightweight, and small as possible, so to satisfy them he turned to a stack of mobile phone cells. Nokia BL-4U cells could be had for under a pound ($1.46) including delivery, so they certainly satisfied his requirement for cheapness.

It might seem a simple procedure, to put together a battery pack, and in terms of physical wiring it certainly is. But lithium-ion cells are not simply connected together in the way dry cells are, to avoid a significant fire risk they need to have the voltage of each individual cell monitored with a special balanced charger. Thus each cell junction needs to be brought out to another connector to the charger.

[Glen]’s write-up takes the reader through all the requirements of safe lithium-ion pack construction and charging, and is a useful read for any lithium-ion newbies. If nothing else it serves as a useful reminder that mobile phone cells can be surprisingly cheap.

Lithium cells have captured our attention before here at Hackaday. Our recent Hackaday Dictionary piece provides a comprehensive primer, we’ve featured another multi-cell build, and an interesting app note from Maxim for a battery manager chip.