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.

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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.

 

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]

Electric Longboard Roundup

ev longboards everywhere!

Everybody and their grandmother is longboarding electric-style these days: here are some of the most recent developments in the world of kickless cruising.

First up, [comsa42] has punched up an excellent step-by-step visual guide for first-time EV hopefuls, detailing the basics of a battery-powered longboard setup and thoroughly explaining the particulars behind component choices. His build is relatively straightforward: combine a board with a low(ish) kV outrunner motor, some LiPo batteries, an ESC (Electronic Speed Controller), a transmitter/receiver, and a few custom parts for gearing and mounting. This build should be commended not only for its simplicity but also for its frugality: [comsa42] estimates a final cost of around only $300, which is a staggering difference from commercial alternatives such as the Boosted Board and newcomer Marbel.

[comsa42’s] other significant contribution is a low-key and low-cost cover to house the electronics. He simply fiberglassed a small enclosure to protect the expensive internals, then mounted and painted it to blend seamlessly with the rest of the deck. You can find loads of other useful goodies in his guide, including CAD files for the motor mounts and for the wheel assembly.

But wait, there’s more! Stick around after the jump for a few other builds that ditch traditional wheels in favor of a smoother alternative. There’s also a smattering of videos, including comsa42’s] guide overview and some excellent cruising footage of the other board builds doing what they do best.

Continue reading “Electric Longboard Roundup”

Finally, an Easy To Make Holder for Lithium Ion Batteries

Lithium Ion Battery holder

For projects requiring a bit more juice, the mass production of those small rectangular lithium ion batteries for cell phones, cameras and other electronics are extremely useful — the problem is, how do you mount them, short of soldering the terminals in place? With a bit of perfboard of course!

[Jason] came up with this idea when he was trying to figure out a way to mount small lithium cells for a battery fuel gauge for another one of his projects. He found if you use good quality perfboard you can use a 90 degree male pin header to contact the terminals, and a strip of female pin header as a kind of battery stop at the other end. This allows you to very snugly squeeze the battery in place — you may need to adjust the length of the male pins though in order to fine tune the fit!

Now you can add a nice wire terminal, solder up the connections, and there you have it, an easy to make, extremely useful battery holder!

Hackaday Links: January 26, 2014

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The automotive industry is rolling more and more tech into their offerings. This is great for us because replacement or salvaged parts are great for projects. Here’s one component to look for. [MikesElectricStuff] tears apart the thermal imaging camera form an Audi. [via Hacked Gadgets]

Give your valentine an analog love note on the big day. [Tom’s] LED heart chaser design does it without any coding. It’s a 555 timer with CD4017 decade counter. The nice thing about the setup is a trimpot adjusts the chaser speed.

[Jan] is overclocking his Arduino to 32 MHz. For us that’s kind of an “eh” sort of thing. But his statement that you need to use a clock generator because the chip won’t work with an oscillator at that frequency raised an eyebrow. We saw an AVR chip running from a 32MHz crystal oscillator in the RetroWiz project from yesterday. So do we have it wrong or does [Jan]? Share your opinion in the comments.

Download a copy of the Apple II DOS source code… legally. Yay for releasing old code into the wild! The Computer History Museum has the DOS source code and a bunch of interesting history about it. [via Dangerous Prototypes]

While we were prowling around DP for the last link we came across [Ian’s] post on a new version of Bus Pirate cables. We’ve got the old rainbow cables which are pretty convenient. But if you’ve used them you’ll agree, hunting for the correct color for each connection isn’t anywhere near a fool-proof method. The new cable uses shrink tube printed with probe labels. They sound like a huge pain to manufacture. But this makes connections a lot easier. In our experience, when it doesn’t work its always a hardware problem! Hopefully this will mean fewer botched connections.

Make your tiny LiPo cells last longer. Not capacity wise, but physically. The delicate connections to the monitor PCB break easily, and the plug is really hard to connect and disconnect. [Sean] shows how he uses electrical tape for strain relief, and a bit of filing to loosen up the connector.

KerbalEdu: Kerbal Space Program for education. That’s right, you can play Kerbal as part of school now. Some may shake their heads at this, but school should be fun. And done right, we think gaming is a perfect way to educate. These initiatives must be the precursor to A Young Lady’s Illustrated Primer method of education. Right?

Hackaday Links: November 3, 2013

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[Michael] just missed the deadline for the Trinket Contest but we still think his tablet is pretty cool. He says it predates the iPad and uses a custom aluminum case, a SoC he ripped from a Gecko Edubook, powered by eight NiMH batteries. Check out the front, the guts, and the sides.

Speaking of portable power sources, After doing a teardown of a 12V 6800 mAh Li-Po battery [Howard] strapped some prototyping equipment to either side of it and now he’s got a prototyping power supply that’s easy to take with him.

Blinky goodness doesn’t have to look hacked together (even if it is). This Raspberry Pi logo looks like a professional sign! It was cut from foam and plastic, primed and painted, then stuffed with addressable LED strips.

While we’re on the topic of refined RPi projects, check out this Raspberry Pi MAME cabinet. It’s a bit bigger than the Galaga cabinet we saw recently but still small enough to keep around the house without getting in the way.

If you’re a fan of automotive hacks you should check out this effort to build an Electronic Diesel Control.

We’ve been saving the gnarliest link for last. [Matthew] laments that his missed Halloween to show off this project. But we don’t think an almost-entirely wooden spider-like walker needs to be paired with a holiday. It’s very cool and somewhat operational, but still needs help working out all of the kinks. Our favorite moment in the video is when [Matthew] exclaims “It wants to live!”.

Upgrading Cordless Drill Batteries to Lithium

Cordless power tool battery replacements are expensive: you can easily spend $100 for a NiCd pack. [henal] decided to skip nickle-based cells and cut out the middleman by converting his old cordless battery packs to inexpensive hobby lithium cells. These batteries appear to be Turnigy 3S 1300mAh’s from Hobbyking, which for around $10 is a great bargain. As we’ve explained before, lithium batteries offer several advantages over NiMH and NiCd cells, but such a high energy density has drawbacks that should be feared and respected, despite some dismissive commenters. Please educate yourself if you’ve never worked with lithium cells.

[henal] gutted his dead battery packs and then proceeded to prepare the lithium replacements by soldering them to the cordless pack’s power connectors. To keep charging simple, he also branched off a deans connector from power and ground. After cutting some holes in the pack for access to the balancing connector and deans connector, [helan] went the extra mile by soldering on a DIN connector to the balancing wires, which he then securely glued to the side of the case.

We’ve featured lithium power tool replacements before, and these Turnigy packs pose the same problem: they don’t appear to have any low voltage cut-off protection. Check out some of the comments for a good solution.