Hackaday Prize Semifinalist: A Smart Battery Analyzer

[K.C. Lee]’s entry for the Hackaday Prize won’t cure cancer, wipe a disease from the planet, stop an alien invasion, or save the world. His battery charger and analyzer is, however, a useful little device for determining the charge and discharge characteristics of batteries, and can also be used as dual channel electronic load, current source, or power supply.

Inside [K.C.]’s device are all the tools required for charging and discharging lithium-ion, lead acid, and NiMH batteries. He’s doing this with a few slightly unusual circuits, including a SEPIC DC to DC converter, and an ‘analog’ PWM controller. these two techniques together mean [K.C.] can get away with smaller caps and inductors in his design, which also means less ripple on the output. As far as battery chargers and dischargers go, this one is very well designed.

Control of battery discharging and charging happens through a SILabs 8051-based microcontroller with USB. The UI is a simple Nokia LCD and an app running in Windows. If you want to save the world, this isn’t the project for you. If you need to test a few rechargeable batteries, this is a great device to have on the workbench.

The 2015 Hackaday Prize is sponsored by:

The Best NiMh Charger?

[Paul Allen] has been working on the latest iteration of his NiMh battery charger and it looks amazing!

We’ve covered [Paul Allen]s awesome hacks and tutorials before, but never this project. What makes his charger so special is it’s ability to monitor and log every aspect of the charging process. Not only does it have a SD card for data logging, but it also interfaces with a Windows application for real-time monitoring as well as analysis and visualization of the charging process (Linux users don’t fret it has a serial interface too).

[Paul] doesn’t say if he plans to open hardware or kickstart the charger, but some of his older posts give us a quick peak at the gerbers. Let’s hope this awesome project makes its way into the wild soon, and hopefully we’ll be able to try it for ourselves and see if it lives up to its name.

MacGyver, Jedi Knights, Ammo Stockpiles, and Candy Crush

Everyone’s favorite machinist, tinkerer, YouTube celebrity, deadpan comedian, and Canadian is back with a tale of popping a few benzos, stumbling around Mexico, and wondering why everyone else on the planet is so stupid.

The hero of our story considered the feasibility of one hundred and eighty-sixth trimester abortions as he stood outside a Mexican airport watching a stockbroker complain about the battery in his cellphone. Meanwhile, cars drove by.

Here’s how you charge a phone with a car battery and an ‘ol Dixon Ticonderoga.

To charge a battery, all you really need to do is connect the terminals to a power source with the right voltage. A cell phone battery needs about three volts, and a car battery has twelve. You need a voltage divider. You can get that with a pencil. Take out a knife, get to the carbon and clay wrapped in wood, and wire the battery up. Make a cut a quarter of the way down this rather long resistor, and there you will find something around three volts.

Does it work? Yeah. It works even better if you have some tape to hold wires onto the cell phone battery when charging. Is it smart? It is if there is no other conceivable way of charging your cell phone. Should you do it? Nah. Video below. Thanks [Morris] for the link.

Continue reading “MacGyver, Jedi Knights, Ammo Stockpiles, and Candy Crush”

A Li-ion Battery Charging Guide

Although [pinomelean’s] Lithium-ion battery guide sounds like the topic is a bit specific, you’ll find a number of rechargeable battery basics discussed at length. Don’t know what a C-rate is? Pfffft. Roll up those sleeves and let’s dive into some theory.

As if you needed a reminder, many lithium battery types are prone to outbursts if mishandled: a proper charging technique is essential. [pinomelean] provides a detailed breakdown of the typical stages involved in a charge cycle and offers some tips on the advantages to lower voltage thresholds before turning his attention to the practical side: designing your own charger circuit from scratch.

The circuit itself is based around a handful of LM324 op-amps, creating a current and voltage-limited power supply. Voltage limits to 4.2V, and current is adjustable: from 160mA to 1600mA. This charger may take a few hours to juice up your batteries, but it does so safely, and [pinomelean’s] step-by-step description of the device helps illustrate exactly how the process works.

[Thanks mansalvo]

An Obsessively Thorough Battery (and more) Showdown

There are a number of resources scattered across the Internet that provide detailed breakdowns of common products, such as batteries, but we haven’t seen anything quite as impressive as this site. It’s an overwhelming presentation of data that addresses batteries of all types, including 18650’s (and others close in size)26650’s, and more chargers than you can shake a LiPo at. It’s an amazing site with pictures of the product both assembled and disassembled, graphs for charge and discharge rates, comparisons for different chemistries, and even some thermal images to illustrate how the chargers deal with heat dissipation.

Check out the review for the SysMax Intellicharger i4 to see a typical example. If you make it to the bottom of that novel-length repository of information, you’ll see that each entry includes a link to the methodology used for testing these chargers.

But wait, there’s more! You can also find equally thorough reviews of flashlights, USB chargers, LED drivers, and a few miscellaneous overviews of the equipment used for these tests.

[Thanks TM]

Hacklet #9 Bugs and Fire

9 This week on the Hacklet, we’re spending some time looking at bugs and fire! honeybeeFirst up we have [Noel] who is saving the bees with Bee-O-Neo-Tweet-O. Bees are incredibly important, both to Earth’s ecosystem and the food chain we humans need to survive. Unfortunately bees are also sensitive to some of the chemicals humans dump into the atmosphere. Sometimes it results in colored honey, but more often than not it’s detrimental to the bees.

Neonicotinoids are a class of insecticide that has been causing problems to hives near where they are used. [Noel] is banking on sensors created with bismuth electrodes to detect the chemical near the entrance to hives. The data can be collected by beekeepers all over the world and sent to a central server. He’s using an Arduino Yun as a WiFi connected base station. Each individual hive has an Adafriut Trinket and a 433MHz radio link to send data to the base. [Noel] is even hoping to detect individual bees by the sound of their wings beating.


[Ken] is keeping his own bees, and wants to monitor more than just chemicals. His honeybee hive monitoring system keeps track of the temperature and weight (and thus the honey produced) by his hives. Rather than buy an expensive load cell setup, [Ken] modified a standard digital bathroom scale to suit his needs. The insects connect to the IOB (Internet of Bees) with a bit of help from the Apitronics platform and a BeagleBone Black. Ken even added a solar-powered weather station with the Apitronics system.

bug-killa[Mike] is taking a slightly different approach. He doesn’t want to save the bugs, he wants to kill the ones that bug him! [Mike] doesn’t want to get his hands dirty, so he’s created Lazy Killer 9000 for easy bug killing. Lazy Killer uses the business end of an electrified fly swatter to do its work. This project wouldn’t be complete without an Arduino, so [Mike] is adding one, as well as a WiFi shield. The entire system will have a friendly interface to turn the juice on. One of the best features of Lazy Killer is the internet connected kill count. [Mike] knows that there aren’t any bugs in the vacuum of space, so he’s entered Lazy Killer in The Hackaday Prize.


From bugs, we move on to Fire! [mr.jb.swe] needed a reliable portable power source. He found it in LiFePO4 batteries, but still needed a way to charge them. Toward that end he’s created The Multicharger, a watt meter and charger which can be powered from solar, wind, or thermometric power. A Powerpot X provides the fire and the power to charge the batteries. [mr.jb.swe’s] charger converts that into the standard constant current->constant voltage charging system needed by lithium chemistry batteries. The Multicharger isn’t a complete battery management system yet, but it’s well on its way.

Unitycandle candles have become a staple at wedding ceremonies.[Quinn] has taken things to the next level and beyond with this take on the classic unity candle. This candle throws fireballs 30 feet into the sky! We covered the candle back in June, but [Quinn] has been busy since then. With over 20 updates, [Quinn] has created one of the most well documented projects on Hackaday.io. Of course, being that this project is dealing with propane and monstrous fires, [Quinn] mentions you shouldn’t try unless you really know what you’re doing. Don’t set any brides on fire! That’s it for this week’s Hacklet! Tune in next week, same hack time, same hack channel, for more of the best of Hackaday.io!

Reviving a Stubborn Laptop Battery

We’ve all gotten bored of certain toys and left them on the shelf for months on end. But what do you do when this prolonged period kills the batteries? Well if you’re [Andrew] you take apart the battery pack and bring it back to life!

[Andrew] picked up one of those Panasonic Toughbooks awhile back and although it’s hardly a top of the line laptop specs-wise, it does have some pretty cool features: it’s shock-proof, splash-proof, and extreme-temperature-proof. It even had a touch screen before touchscreens were cool. Despite its durability, however, the laptop was left to sit for a bit too long, and the battery pack no longer accepted a charge.

[Andrew] quickly disassembled the battery pack and began measuring the cells with his trusty multimeter, assuming just one cell had gone bad. Curiously though, no cells reported 0V. What he did find was that each cell and sub-pack reported 2.95V, which is 0.05V below the “safe operating limits” of typical lithium ion cells. Continue reading “Reviving a Stubborn Laptop Battery”