Got a buck? Make a charger for LiR2032 coin cells. It could hardly be cheaper or easier.
This Lithium battery charger circuit board, based around a TP4056 chip, will set you back all of $0.90. That may be an overestimate. I won an auction this week for 5 of them and paid $1.36, shipping included.
$1 Lithium Coin Cell Charger - [Link]
All-Dock: The fastest docking station in the world. Works with iPhone, iPad, Android, Apple, Samsung, Sony, HTC, Kindle, Nokia, Huawei
The All-Dock is the race car, the Porsche, of charging stations. It’s not just functional – charging multiple devices of nearly every type available – but also incredibly fast and spectacularly beautiful. When this project is completed, the All-Dock will surpass any other charging station in the worldwide market. You can be a part of this amazing effort by supporting us, and by doing so you’ll obtain a product you’ll be proud to display where everyone can see it.
Our dream with the All-Dock is to create more than just a charging station. The All-Dock is envisioned as a functional piece of art. It will offer a solution for the rapid recharging of multiple devices at the same time, compatible with nearly all devices, including Apple, Samsung, Blackberry, LG, HTC, Motorola, Huawei, Microsoft, Nokia, Kindle, Sony Ericsson, Nexus, etc. The All-Dock will enable you to work with, charge, dock and store your device – all with the same station. It will provide incredible value for money.
All-Dock: Universal USB charger for Tablet, Smartphone, etc. - [Link]
FT230X charger detection investigation. Baoshi writes:
I bought some FT230X (FT230XS) USB-USART bridge chip recently for a new design. FT230X is not only cheaper than the traditional FT232RL, but also offers a new fancy “USB charger detection” function. This interests me because I’m quickly running out of desk space and power socket. I wish the new device to be solely powered by USB and/or battery.
FT230X charger detection investigation - [Link]
“Power bank” or a mobile power supply with a USB output can contribute also to your undisturbed work.
Nowadays already almost every battery-operated device with a USB port has a possibility to be operated or recharged through this port. Whether it is a smartphone, external harddrive, various modems, dataloggers and many other specialized devices, almost all of them can be powered/ recharged also from a USB port from an external mobile power source -”Power bank”.
In respect to the fact, that there are still more devices with this possibility, we incorporated to our stable stock offer two types of these power supplies – B110 and B120 from a renowned company Apacer. They differ mainly by a capacity of an in-built battery (4400/ 6600 mAh). B110 has one USB connector with a max. output current of 5V/1A, while a bigger type – B120 features two USB ports with a max current of 1,5A/1A (max 2.1A both ports simultaneously). Both Power banks can be recharged through a micro USB port by means of a supplied short USB cable enabling recharging for example from PC, USB adapter or from still more used wall USB outlets, which are becoming a common part of modern buildings installations, on airports etc. The same micro USB/USB B cable can be consequently used to connect a device which we want to power/ recharge (through an “OUTPUT” connector). A small complement of both types is a 5mm white LED, thus B110 and B120 can serve as a small torch with a long hold-off.
Apacer B110 and B120 – Power banks not only for your smartphones - [Link]
The LTC4120 from Linear Technology is an all-in-one receiver chip for wirelessly charging battery-powered devices. It measures 3 x 3 mm and requires a pick-up coil at its input and a rechargeable battery at its output. A voltage is induced in the coil when it is in close proximity to the transmitter coil of a separate charging unit.
As well as the convenience of just placing your cell phone on a charging pad, this method is also ideal for hand-held devices that can’t use a conventional plug-in charger for reasons of hygiene or harsh/volatile atmospheres.
The battery charging functions allow for both constant current and constant voltage modes and a programmable float voltage level between 3.5 and 11 V accommodates a wide range of cell chemistries. An external resistor sets the charge current up to a maximum of 400 mA. It senses cell voltage and can initiate a low-voltage preconditioning phase if necessary. [via]
LTC4120 – Novel Contactless Battery Charger Chip - [Link]
Alex Sidorenko writes:
From time to time many of us are facing the same problem when trying to charge your smartphone or tablet from the USB port – it just not charging. Recently I have bought USB car charger to power my Samsung Galaxy Tab 10.1 on the road just to discover it doesn’t work. Even though the Galaxy actually sees the charger connected is just marking it as unrecognized power source. I was trying to power up my Motorola Droid 3 phone – it won’t work either. The reason is simple – the Galaxy Tab doesn’t recognize the charging device as “native charger”.
What is “native” charger?
The native charger for smartphone or tablet often have a special voltage signature on USB data pins to let the device recognize the charger and figure out the maximum charging current it can consume from the power source. The intent is twofold. First, it is stopping the device from consuming too much current from the charger. Second, it is preventing the charging from unrecognized power sources. The “unrecognized” is the keyword here, as profiting from selling additional device accessories (chargers) is definitely a business strategy.
Charging your Smartphone from USB without fear - [Link]
Abel Raynus writes:
Rechargeable NiCd (nickel-cadmium) cells are widely used in consumer devices because of their high energy density, long life, and small self-discharge rate. As a part of one project, I needed to design a reliable and inexpensive charger for a battery pack containing two NiCd AA-size 1200-mAh cells. In the process of the charger design, I needed to solve two main problems: first, setting a proper charge-current value, and second, stopping the charging process when the cell is full to avoid overcharging. This Design Idea describes a way to overcome both problems.
Charge a nickel-cadmium cell reliably and inexpensively - [Link]
Joohansson @ instructables.com writes:
The reason for this project was to solve a problem I have. I sometimes do several days of hiking/backpacking in the wild and I always bring a smartphone with GPS and maybe other electronics. They need electricity and I have used spare batteries and solar chargers to keep them running. The sun in Sweden is not very reliable. When you need it as most it´s either raining or other circumstances that makes it impossible to charge with solar panels. Even when it´s clear weather it simply take too long to charge. Batteries are good but heavy. I have looked for alternatives but they are either very expensive or too large.
Smartphone Charger Powered by Fire - [Link]
Peter T Miller writes:
Like other simple, single-cell lithium-ion battery chargers, Microchip’s MCP73812 provides no means of indicating the charging status. You can remedy this situation by adding four components (Figure 1). Add one more LED, and you also get a charging-complete indication. This two-LED configuration has the added benefit that one of the LEDs is always on, providing an indication that the charger is powered.
Add charging status to simple lithium-ion charger - [Link]
Battery-Charging Controllers for Energy Harvesters by Jon Gabay:
Whether your energy harvesting application uses large solar panels with high voltages and currents or, more often the case, must make do with minute amounts of power derived from various other ambient energy sources, one thing is almost certain: some type of energy storage is on board, whether in the form of a small rechargeable lithium ion battery, a supercapacitor, or solid-state energy storage technology. For the engineer this means that not only do we need to design circuits to harvest and convert ambient energy, but we also have to include an energy-harvesting interface (and protection circuitry) as well as a charge controller. This article looks at single chip energy harvesting devices that also provide some form of charge control. It discusses the different conditions under which energy can be extracted as well as what to expect when trying to squeeze power out of the ambient environment. Finally, the article will present some typical integrated solutions for small-sized low-power energy-harvesting designs.
Battery-Charging Controllers for Energy Harvesters - [Link]