The design is based around the MCP1640 IC. It is a 350mA 500Khz boost converter with an integrated switch. Due to it’s design the device requires very few external components to function. One Inductor, two capacitors, and two resistors are all that is needed.
The efficiency ranges from 60% to 90% depending on the load and input voltage.
Single battery boost converter - [Link]
New technology improves both energy capacity and charge rate in rechargeable batteries.
EVANSTON, Ill. — Imagine a cellphone battery that stayed charged for more than a week and recharged in just 15 minutes. That dream battery could be closer to reality thanks to Northwestern University research.
A team of engineers has created an electrode for lithium-ion batteries — rechargeable batteries such as those found in cellphones and iPods — that allows the batteries to hold a charge up to 10 times greater than current technology. Batteries with the new electrode also can charge 10 times faster than current batteries.
The researchers combined two chemical engineering approaches to address two major battery limitations — energy capacity and charge rate — in one fell swoop. In addition to better batteries for cellphones and iPods, the technology could pave the way for more efficient, smaller batteries for electric cars.
The technology could be seen in the marketplace in the next three to five years, the researchers said.
A paper describing the research is published by the journal Advanced Energy Materials.
“We have found a way to extend a new lithium-ion battery’s charge life by 10 times,” said Harold H. Kung, lead author of the paper. “Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today.”
New technology improves both energy capacity and charge rate in rechargeable batteries - [Link]
Lithium-polymer battery charger chips @ Dangerous Prototypes – [via]
Lithium-polymer batteries are an excellent choice for portable projects. They are relatively cheap, hold a significant charge, and last for a long time. The drawback with these batteries is that they require rather complicated charging protocols. You have to watch out for overcharging, undercharging, overheating, etc…
We are looking for a standard part to use in our projects, so we decided to do a roundup of open source lithium polymer chargers from SparkFun, Seeed Studio, and Adafruit. With the exception of Seeed, all the chargers are based on Microchip’s MCP738xx family of battery management ICs that come in SSOP and DFN packages. They handle all the charging algorithms and usually only require a single external capacitor.
Lithium-polymer battery charger chips - [Link]
Freescale Semiconductor introduced the MM912J637 intelligent battery sensor (IBS), which accurately measures the voltage, current and temperature of lead-acid batteries and calculates the battery state, all while operating in harsh automotive conditions. The ability to accurately assess these battery parameters is becoming more important with increases in the number of hybrid vehicles on the road and overall electronic content in vehicles, as well as the introduction of start-stop systems. [via]
Freescale introduces intelligent sensor for car battery monitoring - [Link]
This is a bar-graph voltmeter for a 12V battery based on the well known LM3914 IC.
I have a 12V car battery attached to a regular 500VA UPS and, because the UPS is old and doesn’t have any management options, this is how I measure the amount of charge in the battery.
It was developed mainly because it gives a nice look to the UPS, with its red, yellow and green leds. It is also easier to read than conventional digital or analog voltmeters.
LM3914 Battery Monitor - [Link]
NiMH cells are gaining wide popularity in, amongst other places, digital cameras. The energy density in NiMH cells may be lower than that of lithium ion cells, but the fact that they are, in most equipment, interchangeable with disposable dry cells makes them very attractive power sources. The similar electrical and mechanical considerations of NiMH and to dry cells, translates into a wide supply of relatively low cost cells. Also, in case of an emergency, you can always revert back to dry cells if all your NiMH cells are discharged. NiMH should under ideal charging conditions charge for 14 hours at 10% of their rated hourly capacity.
A CPU based NiMH charger - [Link]
Over 110 years ago, the legendary inventor Thomas Edison was granted a patent for the nickel-zinc (NiZn) battery, but a multitude of technical problems blocked the commercial success of this type of battery, and it vanished into distant memory. However, the situation started to change around 2000, when nickel-zinc battery technology again became a focus of intensive research due certain advantages over nickel-cadmium (NiCd) and nickel metal hydride (NiMH) batteries – in particular a higher cell voltage, which simplifies the use of primary batteries as direct power sources. The EU is also campaigning to prohibit the use of NiCd batteries due to their cadmium content. The first generation of NiZn rechargeable batteries is now available in AAA and AA formats from suppliers such as Conrad and Volkner (in Germany). [via]
Nickel-zinc batteries get a new lease on life - [Link]
Car battery and charging system monitor
This project is about making a simple electronic voltage monitor system for car’s battery and its charging system. It plugs into the car’s cigarette lighter receptacle and displays the instantaneous output voltage across the battery terminals on a 4-digit seven segment LED display. This helps you to get early warnings for possible battery and its charging system problems.
Voltage monitor for car’s battery and its charging system - [Link]
(PhysOrg.com) — A group of scientists in Japan have invented a lithium polymer battery that can be manufactured using only printing technologies.
The project is being carried out by the Advanced Materials Innovation Center (AMIC), which belongs to an Incorporated Foundation called the Mie Industry and Enterprise Support Center (MIESC).
The lithium-polymer battery developed by the group is flexible and designed for flexible solar batteries, flexible displays, or attachment to curved surfaces. It is manufactured using printing technology, which means it can be thinner (around 500 μm) but have an increased surface area than other batteries. It can be produced cheaply, is rechargeable, and can also be laminated.
During the development process the group produced two types of prototype, with output voltages of 2 V and 4 V at ambient temperature. The battery is being developed as part of a three-year research project scheduled to end in March 2011. The group is continuing work on improving the manufacturing technologies to make them suitable for commercial production. The researchers are also working on identifying further applications for the battery.
Japanese scientists invent printable lithium battery - [Link]
A new approach to battery design developed by researchers at MIT could provide a lightweight and inexpensive alternative to existing batteries for electric vehicles and the power grid. It could even make rejuvenating the battery as easy as pumping petrol into a car. The work, which was carried under the guidance of materials science professors W. Craig Carter and Yet-Ming Chiang, is described in a paper published recently in Advanced Energy Materials.
The new battery uses an innovative device called a semi-solid flow cell, in which solid particles suspended in an electrolyte are pumped through the system. These suspend particles form the active, positive and negative electrodes of the battery. They are separated by a filter, such as a thin porous membrane. A key feature of the new design is that separates the energy storage and energy discharge functions into separate physical structures. According to Chiang, this allows the battery to be designed more efficiently. [via]
New battery design uses flow media – [Link]