Lithium cells outperform Nickel Cadmium and Nickel Metal Hydride in almost every way. But they also need a little bit more babysitting to get the most out of them. That comes in the form of control circuitry that charges them correctly and won’t let them get below a certain voltage threshold during discharge. We enjoyed reading about [Carlos’] Lithium cell salvage efforts as it discusses these concerns.
He wanted to salvage a Lithium power source for his projects. He had the three cell pack from a dead Macbook Pro seen in the upper left, as well as the single blown cell from a digital picture frame shown on the right. The three-pack didn’t monitor each cell individually, so the death of one borked the entire battery. He desoldered them and probed their voltage level to find one that was still usable. To prevent his project from draining the source below the 2.7V mark he scavenged that circuit board from the digital picture frame. A bit of testing and the system is up and running in a different piece of hardware.
Don’t be afraid of this stuff. If you learn the basics it’ll be easy to use these powerful batteries in your projects. For more background check out this charging tutorial.
From time-to-time we’ve been frustrated by the lack of backwards compatibility for Apple accessories. We have a great Monster FM transmitter that used the screen of the original iPod to select a channel. That was a feature we just loved which it never worked with any future hardware. We may not be able to get that back, but perhaps this hack can help us implement the ability to charge newer Apple devices using older accessories.
Seen above is the mounting dock from the iPod Hi-Fi speakers released back in 2006. Apparently the sound out of this set of speakers is just great, but you won’t be able to charge your modern device while it’s playing music. That is unless you’re not afraid to solder on a few simple components and roll in a switching regulator which can source at least one Amp of current. As we’ve seen in the past, Apple uses a couple of voltage dividers to identify modern chargers. These are installed on the D+ and D- lines of the USB connector and are pretty easy to recreate if you know the voltage levels the device is looking for. In this case a 39K, two 51k, and one 75k surface mount resistors are free-formed right next to the connector on the Hi-Fi’s dock PCB. The regulator on the right supplies the juice for charging. It’ll charge modern devices now, and even work with the iPhone five if you use a simple dock connector adapter.
If you’re in search of a flashlight that can stand up to the elements, or simply looking for an easy way to spruce up your pool for those hot summer nights, check out these rechargeable PVC LED lights. Inspired by a post in Make: Magazine featuring Indestructible LED Lanterns, [John Duffy] decided to take the project one step further.
While he liked Make’s iteration of the waterproof lantern, he thought it would be best to permanently seal the lights for maximum durability. Not satisfied with a one-use light, he equipped the PVC lanterns with a single rechargeable AA battery, step-up circuitry to drive the LED, and an inductive charging coil.
His floating, waterproof lights sport a slightly bigger footprint than their predecessors to house the extra electronics, but we think that’s more than a fair trade off considering they can be charged wirelessly.
Place your Digikey/Mouser/Jameco orders now and check out [John’s] how-to video – you just might get some of these built in time for the weekend!
Continue reading “Mini waterproof LED lanterns charge without wires”
People quickly find out that I am a dork, and their next question typically is “why do you own that old as dirt dumb phone?”. Well to be honest, I don’t like phones. After a decade of Palm Pilots and Windows CE devices, I really don’t like touch screens either (fat man fingers and a bad habit of chewing nails does not help). I also do not like that in order to get a fancy PDA with a radio you usually have to sign up for a data plan, or pay for the thing in full.
Now get off my lawn! Seriously though, I really only need my phone to do two things, make phone calls, and send SMS messages. If I had a wishlist the only other things I would like is mass storage for MP3 files, and Bluetooth. Naturally when I started my new day job I found the geek in the department and shortly there after I got asked about my basic LG flip phone.
After a few days of interrogation I jokingly snapped back with “well since you are so worried about it why don’t you give me a better phone!” With a little hinting around and a bribe of a “Swiss Roll” at lunch, I was given an old HTC phone with Windows Mobile 5.
While it is not exactly an iPhone or an Android, it is much more featured than what I had, and it has a mini SD card slot and Bluetooth! The only catch was, he could not find the charger. We did not know if the thing even worked (he had never seen the thing turned on) , or what condition the battery was in.
As a good little hacker I took it anyway, join me after the break to see me get it fired up and save a quite a bit of change in the process.
Continue reading “You Want How Much for a Phone Charger?”
Cable management can really be an eyesore, but a little creative camouflage and you can have a cellphone charging station that also serves as decoration.
[Kitesurfer] wanted to use one of the cubbyholes in his new Ikea book shelf for charging but wasn’t keen on the rat’s nest of wires that would go along with it. Also not wanting to take on the challenge of wireless charging he hit the As-Is section of the home furnishing giant and grabbed a leftover board that matched the same finish as the cabinetry. It now serves as a false-back for the charging center behind which a power strip and wall-warts hide.
This covers up the problem, but a blank white box filled with the business end of the charging wires isn’t a whole to better. As with a magic show, the trick is in redirection. [Kitesurfer] cut a hole in the false-back and added the guts of a digital picture frame. Right now he’s got it scrolling through different charging icons, but it’s easy enough to change up the slide-show if he gets tired of them. We’d love to see a subsequent hack that lets the picture frame access the photos on your phone via Bluetooth.
[Derek Hughes] wanted to use inductive charging on his cellphone without voiding the warranty. He picked up a Pixi charging backplate meant for a Palm Pre and scavenged the coil and regulator circuitry from it. To make the electrical connection with his HTC HD2 he removed the mini-USB plug from a charging cable and connected it with 30 gauge wire. The whole package will fit beneath the back plate for use with a Touchstone charger (as we’ve seen with the HTC Evo) but there was one problem. The metal backplate from the HD2 interferes with the inductive charging. For now he’s using tape to hold everything together while searching for a plastic case replacement.
He walks you through the hack in the video after the break. We’re usually not worried about voiding warranties, but a phone like this takes a lot of abuse and having warranty protection or even a service agreement isn’t a bad idea. Continue reading “Inductive cellphone charging without voiding warranty”
[Danny] added wireless charging to his HTC Evo. The hard work was already done for him by Palm, it was just a matter of adding that hardware to his phone. A Touchstone induction charging kit for the Palm Pre will cost you just over $40 for the base station and a replacement back cover. [Danny’s] method removes the induction coil from that cover a relocates inside the case of the Evo. He routes two wires around the battery and solders them to positive and ground connections on the board. Once it’s back together the device draws power without any wires.