Innovating A Backyard Solar Battery System

July 19, 2017 by James Hobson 33 Comments

Ever on the lookout for creative applications for tech, [Andres Leon] built a solar powered battery system to keep his Christmas lights shining. It worked, but — pushing for innovation — it is now capable of so much more.

The shorthand of this system is two, 100 amp-hour, deep-cycle AGM batteries charged by four, 100 W solar panels mounted on an adjustable angle wood frame. Once back at the drawing board, however, [Leon] wanted to be able track real-time statistics of power collected, stored and discharged, and the ability to control it remotely. So, he introduced a Raspberry Pi running Raspbian Jessie Lite that publishes all the collected data to Home Assistant to be accessed and enable control of the system from the convenience of his smartphone. A pair of Arduino Deuemilanoves reporting to the Pi control a solid state relay powering a 12 V, 800 W DC-to-AC inverter and monitor a linear current sensor — although the latter still needs some tinkering. A in-depth video tour of the system follows after the break!

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Rescuing A Proprietary Battery Pack With A Cell From A Camera

July 11, 2017 by Jenny List 9 Comments

If you have an older handheld battery-powered device, you may be fighting a diminishing battery capacity as its lithium-ion cells reach the end of their life. And if you are like [Foxx D’Gamma], whose device is an Alinco DJ-C7 handheld transceiver, you face the complete lack of availability of replacement battery packs. All is not lost though, because as he explains in the video below the break, he noticed that a digital camera battery uses a very similar-sized cell, and was able to graft the camera battery into the shell of the Alinco pack.

Cracking open the Alinco pack, he was rewarded with the rectangular Li-Ion cell and two PCBs, one for the connector and another for the battery management circuitry. By comparison the camera battery had a much smaller battery management PCB, and it fit neatly into the space vacated by the Alinco cell once those covers had been removed. A fiddly soldering job to attach the connector PCB, and he was rewarded with a working Alinco pack and an unexpected bonus when he found out that the transceiver was a dual band model.

Along the way he’s at pains to point out the safety aspects of handling Li-Ion cells, and to ensure that the polarity of the cell is correct. It’s also worth our reminding readers that these packs must always be accompanied by their battery management circuitry. The result though is pleasing: a redundant piece of equipment made obsolete by a proprietary battery, given a new lease on life.

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Solar Bulldozer Gets Dirty

June 7, 2017 by Bryan Cockfield 33 Comments

As the threat of climate change looms, more and more industries are starting to electrify rather than using traditional fuel sources like gasoline and diesel. It almost all cases, the efficiency gains turn out to be environmentally and economically beneficial. Obviously we have seen more electric cars on the roads, but this trend extends far beyond automobiles to things like lawn equipment, bicycles, boats, and even airplanes. The latest in this trend of electrified machines comes to us from YouTube user [J Mantzel] who has built his own solar-powered bulldozer.

The fact that this bulldozer is completely solar-powered is only the tip of the iceberg, however. The even more impressive part is that this bulldozer was built completely from scratch. The solar panel on the roof charges a set of batteries that drive the motors, and even though the bulldozer is slow it’s incredibly strong for its small size. It’s also possible for it to operate on solar alone if it’s sunny enough, which almost eliminates the need for the batteries entirely. It’s also built out of stainless steel and aluminum, which makes it mostly rust-proof.

This is an impressive build that goes along well with [J Mantzel]’s other projects, most of which center around an off-grid lifestyle. If that’s up your alley, there is a lot of inspiration to be had from his various projects. Be sure to check out the video of his bulldozer below as well. You don’t have to build an off-grid bulldozer to get started in the world of living off-the-grid, though, and it’s easy to start small with just one solar panel and a truck.

Thanks to [Darko] for the tip!

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A Mobile Bar In A Trailer!

June 4, 2017 by James Hobson 4 Comments

Ok, there are some worthy laws in place regulating the sale and distribution of alcohol — and for good reason. For many a bootlegger, however, the dream of renovating an old trailer from 1946 into a mobile bar is a dream that must– wait, what? That already exists?

It’s no mobile workshop, but the bar was initially built to accommodate guests at their wedding. [HelloPennyBar] has shared the reconstruction process with the world. Inside, there’s everything you’d need to serve beverages, including a (double) kitchen sink. In addition to a water tank, a pair of car batteries serve as the central power with electrical work installed for interior lights, a small fan to keep the bartenders cool, exterior lights, a water pump, the trailer lights, and more exterior lights so the patrons can party the night away.

Before you say anything, [HelloPennyBar] says they would need a license to sell alcohol, but alleges that for serving alcohol at private events in their state it suffices to have an off-site responsible serving license. Furthermore, a few helpful redditors have chimed in regarding battery safety and cable-mounts, to which [HelloPennyBar] was amenable. Safety and legality noted, the mobile bar must make for a novel evening of fun.

[via /r/DIY]

DIY USB Power Bank

May 21, 2017 by Eric Evenchick 47 Comments

USB power banks give your phone some extra juice on the go. You can find them in all shapes and sizes from various retailers, but why not build your own?

[Kim] has a walkthrough on how to do just that. This DIY USB Power Bank packs 18650 battery cells and a power management board into a 3D printed case. The four cells provide 16,000 mAh, which should give you a few charges. The end product looks pretty good, and comes in a bit cheaper than buying a power bank of similar capacity.

The power management hardware being used here appears to be a generic part used in many power bank designs. It performs the necessary voltage conversions and manages charge and discharge to avoid damaging the cells. A small display shows the state of the battery pack.

You might prefer to buy a power bank off the shelf, but this design could be perfect solution for adding batteries to other projects. With a few cells and this management board, you have a stable 5 V output with USB charging. The 2.1 A output should be enough to power most boards, including Raspberry Pis. While we’ve seen other DIY Raspberry Pi power banks in the past, this board gets the job done for $3.

Cordless Water Pump!

April 2, 2017 by James Hobson 28 Comments

A water pump is one of those items that are uncommonly used, but invaluable when needed. Rarer still are cordless versions that can be deployed at speed. Enter [DIY King 00], who has shared his build of a cordless water pump!

The pump uses an 18 volt brushed motor and is powered by an AEG 18V LiPo battery. That’s the same battery as the rest of [DIY King]’s power tools, making it convenient to use. UPVC pipe was used for the impeller — with a pipe end cap for a housing. A window of plexiglass to view the pump in motion adds a nice touch.

A bit of woodworking resulted in the mount for the pump and battery pack, while a notch on the underside allows the battery to lock into place. Some simple alligator clips on the battery contacts and the motor connected through a switch are all one needs to get this thing running.

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Morbid Battery Uses Blood Electrolyte

March 19, 2017 by Bryan Cockfield 22 Comments

Building a battery out of common household products is actually pretty simple. All that is required is two dissimilar metals and some sort of electrolyte to facility the transfer of charge. A popular grade school science experiment demonstrates this fairly well by using copper and zinc plates set inside a potato or a lemon. Almost anything can be used as the charge transfer medium, as [dmitry] demonstrates by creating a rather macabre battery using his own blood.

The battery was part of an art and science exhibition but it probably wouldn’t be sustainable on a large scale, as it took [dmitry] around 18 months to bank enough blood to make a useful battery. Blood contains a lot of electrolytes that make it perfect for this application though, and with the addition of the copper anode and aluminum cathode [dmitry] can power a small speaker which plays a sound-generating algorithm that frankly adds a very surreal element to the art installation.

While we can’t recommend that you try to build one of these batteries on your own without proper medical supervision, the video of the art piece is worth checking out. We’ve seen a few other hacks that involve blood, but usually they are attempting to use it for its intended purpose rather than as an alternative energy source.