Electric tricycle build log is like hacker crack

electric-tricycle-burns-rubber

This tiny little scratch-built electric tricycle is a insanely powerful. Some might think you don't need a crash helmet for testing a trike, but seeing the video after the break where [Ben Katz] is flying through a parking garage while slaloming between the support beams proves that this ride has some pep to it. Looking through the presentation post linked above is fun, but when we started … [Read more...]

Battery teardown to get at the cells inside

battery-teardown

Most of what people call batteries are actually cells. All of the common disposable alkaline batteries from AAA to D are single cells. The exception is the 9v battery which actually has six smaller cells inside of it. [Tom] took a look inside three different batteries to see what cells they're hiding. Since he no longer uses the batteries for their intended purposes the individual cells may find a … [Read more...]

Welding with over a hundred A123 Lithium cells

a123-cell-powered-welder

[Doctor Bass] needed to do some welding on his electric bicycle. The problem is that he's never welded before and doesn't have any tools for it. As you can see, that didn't stop him. He used a bicycle battery made from reclaimed DeWalt A123 cells to power his diy welding rig. He has a huge adjustable resistor which is responsible for limiting the current. 80 Amps seems to work the best with … [Read more...]

LiPo internal resistance measurement tool

lipo-internal-resistance-meter

This is a scratch-build meter for measuring the internal resistance of Lithium Polymer cells. [Bleuer Csaba] uses the LiPo cells for RC vehicles and thet take quite a beating from the motors  they're supplying. This means that he only gets about 100-200 cycles out of each cell. To figure out where one is in its life cycle you can measure the internal resistance where a rising resistance … [Read more...]

Open source capactive charger resurrects an electric skateboard

mikey-sklar-on-electric-skateboard

Here's [Mikey Sklar] posing on his new electric skateboard. Well, it's new to him at any rate. He bought it used on eBay for $250. That may not sound like much of a deal, but these will run more like $800 retail. The savings comes because the thing would no longer charge. But it took him just an hour and a half with his capacitive charger to resurrect the flat lithium cells. The first thing he … [Read more...]

Testing 30 brands of batteries

batt

Batteries come packaged in bright blister packs emblazoned with vague guarantees such as "45% more pictures" and "five times longer lasting." During his internship at BitBox this summer, [Thomas] decided to put those statements to the test. He tested thirty brands of batteries on a homebrew rig to find the batteries with the most power and the most bang for your buck. The hardware [Thomas] … [Read more...]

Passion Fruit acquire laser defenses

passion-fruit-powered-laser

Apparently being overrun by ripe Passion Fruit is a problem if you live in Hawaii. [Ryan K's] solution to the situation was to use his extra fruit to power a laser. In an experiment that would make [Walter White] proud, [Ryan] gathered everyday supplies to form a battery based on the fruit. He used some galvanized bolts as the source of zinc. It forms one pole of each cell, with a thin copper … [Read more...]