battery

416 Articles

Cellphone Battery Booster Built At The Checkout Counter

October 29, 2011 by 40 Comments

When you’re away from home and your cellphone runs out of juice it can be a real downer. Sure, you could find a store and buy a wall charger, but wouldn’t it be more fun to build your own battery booster without using tools? [Spiritplumber] did just that, popping into a Radio Shack for the parts, then making his how-to video (embedded after the break) while standing at the checkout counter. You can see he hust set his camera on top of the battery display case and got to work.

He’s using four D cell batteries to provide 6 volts of power. Assuming your phone charges at 5 volts this is going to be just a bit too high, even though there’s some tolerance with most phones. To overcome that obstacle he added a diode to the circuit, taking advantage of the 0.7 volt drop that it brings to the mix. Grab a plug adapter for your model and then just hand twist the connections. [Spiritplumber] admits it would be better to solder these, but in a bind you can get away with it. We looked up some prices for this method and we figure this would cost around $18 (batteries included) depending on the price of the plug adapter for your phone.

Of course if you’re just looking for a way to charge your phone without paying consumer prices there are ways of accomplishing that as well.

Continue reading “Cellphone Battery Booster Built At The Checkout Counter” →

Halloween Props: Pumpkin Battery

October 18, 2011 by 10 Comments

This one would make a nice centerpiece for your Halloween party. It’s a battery with tiny pumpkins serving as the cells. [EM Daniels] shows us how to clear out the pumpkins, fill them with some freshly mixed electrolyte, and he even throws in the directions for baking the pumpkin seeds.

Each pumpkin will need a pair of conductors made of dissimilar metals to serve as the anode and cathode. Copper wire is used for one, aluminum for the other, and both wires have a spiral pattern bent on one end to increase the surface area that contacts the electrolytic solution. Now just boil up a slurry of vinegar, gelatin, and salt, then let it sit in the fridge over night. [EM Daniels] was able get 1.5V out of this project (enough to light one LED) for two hours, and 1.4V for six hours by using seven of the pumpkin cells in series.

[Thanks Karen]

A Simple Fix To Resurrect Your Broken Iclicker

September 12, 2011 by 34 Comments

simple_iclicker_battery_fix

If you are currently attending college, the odds are that you are familiar with iclicker classroom remotes. If you have one of these, you might also be aware that they tend to be flaky at times, particularly when it comes to powering on. [Todd] received a few “broken” iclickers lately and has found an easy to fix design issue that might possibly save yours (and others) from the trash heap.

When he started pulling the units apart to diagnose them, he noticed that something with the battery contacts was not quite right. They are held in place by the device’s plastic shell which is pretty common, however in the iclicker, the portion of the plastic case that holds the positive battery contact is too big, preventing some batteries from making a complete circuit.

Now you might be thinking to yourself that AA batteries are all the same, but they are not necessarily created equal. Through a small bit of testing, [Todd] found that many different batteries experienced intermittent connectivity issues depending on the height of the positive terminal, and that due to their design, Duracell batteries flat out didn’t work. With the careful removal of a portion of the plastic surrounding the positive contact, [Todd] was able to fix each of his “broken” remotes.

He hopes that this information helps some people resurrect their non-functioning units, because a few minutes work sure beats buying another $30 iclicker.

Feel The Hum Of Electricity Between Your Legs

August 10, 2011 by 21 Comments

Here’s a little eye candy for motorcycle enthusiasts everywhere. This is the newest iteration of [Julian’s] electric motorcycle. He obviously knows what he’s doing because everything fits into the frame in a way that is still very pleasing to the eye. But this is actually slimmed down from the original design. If you take a look a back at some of his older posts you’ll see that the four relatively small lithium batteries are a new addition.

The frame was designed to hold four lead-acid batteries. Those things really take up a lot of space and add considerable weight to the vehicle. His recent upgrade was also accompanied by a re-gearing that allows him to reach higher speeds (although he doesn’t say what the top speed actually is). You can’t really see it above, but [Julian] included a wooden insert where the tank on a gasoline motorcycle would have been. It houses control switches as well as a 48V voltmeter. It’s a fantastic finishing touch like the cherry on a sundae.

Bypassing Manufacturer-imposed Battery Lockouts

July 21, 2011 by 62 Comments

sony_battery_cell_swapping

When [Barret] went to use his camera the other day it kept shutting down on him, and upon inspecting the battery, he found that it was a bit swollen. Knowing that he needed a replacement, he turned to an aftermarket battery he had sitting around, but grew pretty annoyed when his Sony Cybershot camera would not accept it.

Apparently a recent firmware update causes his camera to reject non-Sony batteries, a situation he describes as “battery DRM”. There was no way he was going to pony up another $50 to Sony instead of using the perfectly good $10 battery he already had, so he decided to rectify the issue himself.

He stripped both batteries of their plastic coatings, revealing the lithium cells and their charging circuits. He desoldered the PCB from his Sony battery, transplanting it to his aftermarket battery after a little bit of trimming. He wrapped everything up with some tape and gave his franken-battery a spin. It worked a treat, and he was so satisfied with it that he did a similar swap in his aging Logitech mouse.

As more and more companies lock competitors out of the user-replaceable consumables market, these sorts of hacks are certain to become more and more prevalent.

Automotive Battery Voltage Monitor

July 13, 2011 by 32 Comments

car_battery_voltage_monitor

[Rajendra’s] car had just about all the bells, whistles, and gauges he could dream of, but he thought it was missing one important item. In an age where cars are heavily reliant on intricate electrical systems, he felt that he should have some way of monitoring the car’s battery and charging system.

To keep tabs on his car’s electrical system, he built a simple device that allows him to monitor the battery’s instantaneous voltage when the car is powered off, as well as the charging voltage across the battery when the car is running. A PIC16F1827 runs the show, using a simple voltage divider network to step the input voltage down to an acceptable level for use with the PIC’s A/D conversion channel. The resultant measurements are output to a four digit 7 segment display, mounted on the front of the device.

He says that the voltage monitor works quite well, and we’re sure he feels a lot better about the health of his car’s charging system. For anyone interested in keeping closer tabs on their car, he has a circuit diagram as well as code available on his site.

DIY Battery Reconditioner Saves Old Rechargeable Batteries From The Landfill

June 26, 2011 by 20 Comments

rechargeable_battery_reconditioner

Instructables user [msuzuki777] had amassed quite a collection of batteries over the years, but was finding that some of his rechargeable AA and AAA cells seemed to be at the end of their useful life. After reading some information at the Battery University regarding the restoration process for nickel-based batteries, he figured he might as well try building a battery reconditioner of his own.

He worked through several designs that either flat-out did not work, or had issues that limited the number of batteries he could simultaneously recondition. After reading about this rechargeable battery capacity tester we featured a few months back, he was ready to give the project one more try.

It seems that the third try was the charm, because his FET-based design worked quite well. He ended up wiring two FETs to each battery, which are connected via a relay. The batteries get discharged until the voltage drops down to 1V, at which point one FET is turned off, allowing the batteries reach their target voltage of 0.4V more slowly.

Despite the self-proclaimed messy layout of his circuit, [msuzuki777] is quite happy with the results. He has been able to recover several batteries, which is a fantastic alternative to letting them decay in a landfill.