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]
Phil Gonski, Christine Placek writes:
We propose to build a solar battery charger that will charge a variety of batteries: NiMH, NiCd, Li-ion, lead acid. Although there are solar battery chargers on the market, most are only for one application: cell phone, NiMH batteries, etc. Our charger will have the user input the battery type, capacity, and voltage. It will display the charge status and incorporate various safety systems, including temperature monitoring and battery polarity checking.
Solar Powered Battery Charger - [Link]
I have designed many small footprint PIC projects (such as, pocket watches and wristwatches) but I cannot make them really portable. To make them portable, I need small power sources. Of course, Coin Cell battery would be the smallest DC source that I can buy. The problem is that a Lithium button cell provides 3 V. which is not enough to drive my projects. I thought about using DC-DC step-up converter to boost 3 V. to 5 V. However, it’s a little bit complex to add DC-DC converter to the projects. Moreover, my projects consume a lot of power as they consist of many LEDs, a button battery will not last for a day. So, I stopped my think at that point.
USB Coin/Button Cell Battery Charger - [Link]
Power packs to propel your projects! – If you want to take your project portable you’ll need a battery pack! For beginners, we suggest alkaline batteries, such as the venerable AA or 9V cell, great for making into larger multi-battery packs, easy to find and carry plenty of charge. If you want to go rechargable to save money and avoid waste, NiMH batteries can often replace alkalines. Eventually, however you may want to upgrade to the shiniest new technology – rechargable lithium ion/polymer batteries…
Li-Ion & LiPoly tutorial. Power packs to propel your projects! - [Link]
Hey, real EE types out there, is there any reason I can’t monitor 12V battery voltage using a simple voltage divider into an A/D input of a microcontroller that’s powered by a voltage regulator on that same battery?
Monitoring Battery Voltage - [Link]