For his Beyond Unboxing series, [Charles] tore apart a Ryobi cordless chainsaw to get a better look at how this battery powered tool works.
Inside he found a three-phase motor and controller. This motor looks like it could be useful in other projects since it has a standard shaft. The battery pack was popped open to reveal a set of LG Chem 21865 cells, and some management hardware.
With all the parts liberated from the original enclosure, [Charles] set up the motor, controller, and battery on the bench. With a scope connected, some characterization of the motor could be done. A load was applied by grabbing the spinning shaft with welding gloves. [Charles] admits that this isn’t the safest way to test a motor.
While it is a very fast motor, the cut-in speed was found to be rather low. That means it can’t start a vehicle from a stop, but could be useful on e-bikes or scooters which are push started.
This chainsaw a $200 motor, controller, and battery set that could be the basis of a DIY scooter. It sounds great too, as the video after the break demonstrates.
[Thanks to Dane for the tip!]
Continue reading “Electric Chainsaw Teardown”
[cpldcpu] recently received an external USB battery as a promotional gift and thought it would be a good idea to tear it down to see its insides. At first glance, he could see that the device included a USB micro-b socket used as a 5V input (for charging), a USB-A socket for 5V output, a blue LED to indicate active power out and a red one to indicate charging.
Opening the case revealed that most space was taken up by a 2600mAH ICR18650 Li-Ion battery, connected to a tiny PCB. A close inspection and a little googling allowed [cpldcpu] to identify the main components of the latter: a battery mangement IC, a 2A boost converter, a 3A Schottky diode, a few 2A N-Mosfets, a 300mA 2.5V LDO and an unknown 6-pin IC. It is very interesting to learn that every last one of these components seems to be sourced from China, which may explain why this USB battery is given for free. Do you think they designed it in-house and outsourced the manufacturing, or is this a product Digi-Key simply bought and put their name on?
Editorial Note: Digi-Key is an advertiser on Hackaday but this post is not part of that sponsorship. Hackaday does not post sponsored content.
Continue reading “Tearing Down a Cheap External USB Battery”
Knowing different ways of generating light is a great skill to have, so go ahead and add this one to your arsenal by combining a Bugzapper with a CFL Light Bulb.
Sure a CFL(Compact Fluorescent Lamp) works just fine on its own if you have AC mains, but what we’re talking about here is getting the light bulb to work off of a single D battery. We featured a similar hack a few months back by using a Joule-Thief to get the high voltage for the fluorescent tube, but if you can’t get your hands on discrete components, [Jan] shows us another way by gutting a tennis racket bugzapper for its booster board. Knowing that the bugzapper steps up the 3V to about 2000V, he decided to see if that same circuit would run off a single 1.5V D battery and achieve the voltage required to drive a CFL tube. After carefully removing the electronics from the CFL housing, [Jan] was able to directly connect the booster board to the electrode wires of the fluorescent tube, and voila; he now has a D-Battery operated camp light that has a run time of over 200 hours.
It would be interesting to see how this hack compares to the Joule-Thief method in terms of brightness and run-time. Before you go and scrap the parts out of the CFL light bulb, make sure you check out this detailed breakdown of popular CFL light bulbs.
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”
When the power went out at his parents’ shop and ruined the contents of their fridge, [Lauters Mehdi] got to work building a custom power failure alert system to prevent future disasters. Although some commercial products address this problem, [Lauters] decided that he could build his own for the same cost while integrating a specific alert feature: one that fires off an SMS to predefined contacts upon mains power failure.
The first step was to enable communication between an Arduino Micro and a Nokia cell phone. His Nokia 3310 uses FBus protocol, but [Lauters] couldn’t find an Arduino library to make the job easier. Instead, he prototyped basic communication by running an Arduino Uno as a simple serial repeater to issue commands from the computer directly to the phone, and eventually worked out how to send an SMS from the ‘duino. [Lauters] then took the phone apart and tapped into the power button to control on/off states. He also disconnected the phone’s battery and plugged it into an attached PCB. The system operates off mains power but swaps to a 1000mAH 9V backup battery during a power outage, logging the time and sending out the SMS alerts. A second message informs the contacts when power has been restored.
Head over to [Lauters’s] project blog for schematics and photos, then see his GitHub for the source code. If you want to see other SMS hacking projects, check out the similar build that keeps a remote-location cabin warm, or the portable power strip activated by SMS.
[Hackett’s] back at it, this time with some practical advice for the next power outage to hit your city: why not prepare for the worst by building your own bike generator? You’ll no doubt recall that hurricane Sandy devastated New York City’s grid, even flooding substations and causing massive explosions. [Hackett] experienced the Sandy outages first-hand, and knows the value of having this simple build ready to roll.
The project uses a permanent magnet DC motor (around 250 watts), which you can find in electric wheelchairs or other mobility scooters. His setup’s gear reduction spins the motor 50 times for each revolution of the bike wheel. The apparatus [Hackett] built to press-fit the wheel to the motor’s spindle is particularly clever: a threaded rod adjusts the position of the motor, which is bolted onto a hinged platform, with the other part of the hinge welded to a larger frame that supports the bike wheel.
The motor is connected to a home-built charge controller based on Mike Davis’s design, which monitors the deep-cycle batteries and both kills the charge when it’s full as well as turns charging back on after it’s reached a set level of discharge. The rest is gravy: with the deep cycle battery connected to a power inverter, [Hackett] can plug in and keep phones charged, music playing, and even (some of) the lights on. If you’re a fan of [Hackett’s] straightforward, practical presentation style, check out his tripod build and his demonstration of stripping pipes of their galvanization.
Continue reading “Bicycle Generator for Emergency Electricity”
While browsing through his local dollar store, [Taylor] came across a suspicious looking rock that, upon closer inspection, turned out to be a solar garden light. He scooped it up, took it home and cracked it open, modding it to function as a handheld solar flashlight.
Inside was a pathetically small 40mAh rechargeable battery, which he upgraded to a more standard rechargeable AA. The garden rock came pre-built with its own boost converter to kick up the voltage for the LED, but it was fairly dim. We’re guessing [Taylor] didn’t bother reverse engineering the converter and instead simply did some trial and error, but he managed to increase the LED’s brightness by slapping on a different value inductor.
As fun as it may be to have a rock for a flashlight, [Taylor] decided to cobble together a custom case out of a spare USB charger, making a battery holder and adding a pushbutton. The result is a handy solar flashlight that takes around five hours to charge. Check out some other custom lights: a lithium-powered PVC flashlight or one with a snazzier aluminum body and interchangeable heads.