Simple trick for replacing Game Boy cart batteries while retaining game saves

May 2, 2012 By Leave a Comment

[Adr990] wants to make sure his Game Boy game saves aren’t lost to aging batteries. They’re stored in SRAM with a small coin cell inside the cartridge to keep the memory energized when the game is not being played. But if you pull out the battery in order to replace it the data will be lost in the process. It turns out that you can hot-swap the battery without too much effort. As shown in the video after the break, he disassembled the case of the cartridge, then replaced the battery while the Game Boy is switched on. The edge connector feeds power which will keep the SRAM active while the backup battery is removed. We’re sure this could be done with a bench supply as well, but you’ll need to do your own testing before risking those prized game saves.

The other option is to backup your SRAM before replacing the batteries. We’ve seen an AVR-based cartridge dumper, and also one that uses an Arduino. Both should be able to read and write SRAM data. [Read more…]

Filed Under: gameboy hacks, repair hacks Tagged With: , , , , ,

Shocking use of ice cube trays

April 16, 2012 By Leave a Comment

Looks like ice-cube trays are once again proving their versatility as this one is serving as the vessel for a home made lead-acid battery. With a collection of uniformly sized non-conductive containers, it makes the perfect base for a set of small cells. This project is the culmination of a Hackerspace class about batteries, and was put together to turn theoretical knowledge into a hands-on lab.

This is a captured image from the low-quality video found after the break. [Carpespasm] describes the setup; the black pieces are lead plates which are bent into a U-shape to straddle two ice-cube compartments. The each end of the plate is dipping into the acid to make the connection. Once assembled the battery was connected to a charger for about two hours. It puts out 8.5V and is tested by powering an LED cube. This works for just a short period and really drives home the lesson that battery concepts are easy to understand, but reliable battery technology is a bit harder to achieve.

[Read more…]

Filed Under: chemistry hacks, Hackerspaces Tagged With: ,

Powering a robot with a macbook battery

April 1, 2012 By Leave a Comment

When [Soo-Hyun]’s friend had an Apple Macbook Pro battery that began to swell, his friend did the reasonable thing and donated it to be used in a robot. Now [Soo-Hyun]’s kiwi drive robot is powered by a gigantic LiPo battery, giving it a huge range and a very fast top speed.

The defunct laptop battery that formerly powered a 15″ macbook pro is three battery packs of two cells in parallel, delivering 12.6 Volts. To get the power to the robot, [Soo-Hyun] etched a simple PCB that fit into the slot in the battery. A little bit of soldering later, and mounting the battery as a shark fin because of the 8×8 inch limitation of maze-solving robots, the power plant was complete.

Using a bulging LiPo battery probably isn’t the smartest idea (listen for the great line, “it got the camera and my face” at 4:08), but as long as [Soo-Hyun] keeps an eye on the battery as it’s charging, it should be alright.

Check out the video of the robot zipping around on 12.6 Volts after the break.

[Read more…]

Filed Under: robots hacks Tagged With: , , ,

Coin cell battery charger

March 28, 2012 By Leave a Comment

[Jay Kickliter] built his own coin cell battery recharger. This won’t work on the vast majority of coin cells as they are manufactured as disposable parts. But there are rechargeable options out there with model numbers that start with LR instead of CR. In this case he tailored the charging circuit around MCP73832 IC and chose components best suited for charging his 110 mAh LR2450. But we believe all of the LR options out there are rated for 3.6V so altering his design for use with different models should be a breeze.

We’ve been unhappy with the use of disposable coin cell batteries for some time. Sure, in a real-time clock where the cell might last 6-8 years this is not very wasteful. But in an Apple TV remote that gets a lot of use, we hate the choice of a disposable battery. All of our less-hip remotes which use AA or AAA have NiMH rechargeables in them and have used the same pair for year and years. So we’re happy to see this charger project come along.

Now the bad news. We looked around and indeed you can find LR2032; a rechargeable replacement for the CR2032. But the capacity rating falls way flat. The model we looked at boasts only 50 mAh while the disposable CR2032 offers something along the lines of 240 mAh. Hopefully this will change as battery tech evolves.

Filed Under: green hacks Tagged With: , , , , ,

Squeezing the juice out of some AA batteries

February 27, 2012 By Leave a Comment

[Ray’s] breadboard power supply lets you drain the last traces of power from ‘dead’ AA batteries. Electronics that are powered off of disposable alkaline batteries have a cutoff voltage that usually leaves a fair amount of potential within. Since many municipal recycling programs don’t take the disposables (you’re just supposed to throw them in the trash!) we love the idea of squeezing them for prototyping use.

His design uses just one IC, the MCP1640, along with a handful of passive components. The chip is a boost converter with a startup voltage of just 0.65V, which means the batteries themselves – normally starting life above 1.5V – can be used until they drop to about 0.3V each.

Above you can see the kit he is selling. But it’s an open source project and the circuit is so simple we’re sure you can build your own. Add that boost converter chip to your next parts order for around $0.40.

[Ray] made a nice demo video for the device which you can see embedded after the break.

[Read more…]

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Hackaday Links: February 1, 2012

February 1, 2012 By Leave a Comment

The only thing he needs now is a micro and RTC

For [Dino]’s 44th Hack A Week extravaganza, he made powered window blinds in five minutes. It’s a simple build with a small gear motor and a bit of tubing to adapt the shaft to the control rod of the blinds. Good job [Dino].

BecauseCamelCaseWillKillYourPinkieFinger

The wonderful [Lizzie] over at LUSTlab realized that typing meta keys really slows down the development process. The result? Foot pedals for the Shift and Command keys. No build log for this one, but it’s just a set of old racing pedals and a disused keyboard.

So much cooler than a potato

[mdevaev] out of Russia built a fully articulated GLaDOS replica. Here’s the build album and the relevant MLP forum post. This GLaDOS is tiny – probably less than a foot long, but it moves around and speaks (Russian, which is weird). Somebody get us a couple of motorcycle fenders so we can build the 1:1 scale version.

Visualizing a plane of fog

[greg] was looking for a way to visualize the chaotic turbulence of air. He mounted a laser on a computer fan and held some dry ice above the beam. The result looks like it could make for an interesting photography project, but check out the video if you don’t believe us.

We were asking for it

We asked for battery charging circuits that don’t use specialized parts. [Petr] found this one that only uses few transistors, a MOSFET and a voltage regulator. In one of the Hackaday comments, [atomsoft] had the idea of putting a USB plug on the traces to save a bit in component costs. [mohonri] said he designed one, but we have yet to see it. Perhaps next links post…

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