Tag Archives: Battery

Lithium-Ion Battery Warms Up, Operates In Subzero Temperatures

ACB-1453168996220

Charles Q. Choi @ spectrum.ieee.org discuss about a new type of li-ion battery able to work in low temperatures.

A new “all-climate” lithium-ion battery can rapidly heat itself to overcome freezing temperatures with little sacrifice in energy storage capacity and power, researchers say.

This advance might enable applications for which high-performance batteries are needed in extremely cold temperatures, such as electric cars in cold climates, high-altitude drones, and space exploration. EC Power is now creating all-climate battery cells in pilot-production volumes that can be put directly in vehicles, says study lead author Chao-Yang Wang, a mechanical and electrochemical engineer at Pennsylvania State University.

Lithium-Ion Battery Warms Up, Operates In Subzero Temperatures – [Link]

Battery Powered Frequency Meter (0 to 20kHz)

The circuit is a simple digital frequency meter that is made of a frequency-to-voltage converter and an analog-to-digital display converter that can be operatedfrom a single 9-volt battery. The TC7126 ADC generates the voltage required by the TC9400 FVC with internal regulators. The TC7126 is designed to directly drive a 3-1/2 digit, non-multiplexed LCD display so no digital conversion is required.

The input circuit is made up of a current limiting resistor (33kΩ), a DC blocking capacitor (0.01µF), a clamping diode (1N914), and a biasing resistor (1MΩ). The diode acts as a soft clamp to prevent negative going transitions from latching the comparator input and the 33kΩ resistor limits the current during the positive transitions. The gain (VOUT vs. FREQIN) of the TC9400 is determined by the charge-balance capacitor and the integrator feedback resistor (620kΩ) that has been selected for an output of approximately +2V (referenced to ANALOG COMMON) with frequency input of 20kHz. The bias resistor (12kΩ) determined the input threshold of the comparator and has been selected for an input sensitivity range of 250mV to 10V peak-to-peak of a sine or square wave on the input of the FVC.

The TC7126 will have a maximum positive input of about 2V since the input is referenced to ANALOG COMMON that is only 3V below V+. The internal voltage swing of the integrator does not have the same limitation because a positive input results in a negative swing of the integration. A fully charged battery will give a range of about 6V. The integration components (1MΩ and 0.047µF) at pins VBUFF and VIN are selected, in conjunction with the oscillator frequency to have an integrator ramp amplitude of about –3V with a 2V input from the TC9400. The oscillator is set up to run at 48kHz (150kΩ and 50pF) for maximum rejection of stray power-line pickup. This will result in the TC7126 running at three conversions per second.

Battery Powered Frequency Meter (0 to 20kHz) – [Link]

Supercapacitors to replace batteries?

Microsoft PowerPoint - ????1

by Martin Cooke @ elektormagazine.com:

It was reported last year that researchers at Rice University in the US, led by chemist James Tour had developed a method of producing a form of graphene on commercial polyimide plastic sheet by zapping it with a laser. The process is called LIG (Laser Induced Graphene). The resulting graphene layer is not a conventional flat sheet made up of hexagonally-organized atoms but instead a spongy array of graphene flakes attached to the polyamide, giving a greatly increased surface area. This property can be exploited to build supercapacitors.

Supercapacitors to replace batteries? – [Link]

One step closer to the ‘ultimate battery’

lithium-air-battery-demonstrator

Erica Torres @ edn.com discuss about lithium-air batteries that looks promising for future use.

Although scientists are still working toward replacing lithium-ion (Li-ion) batteries with lithium-air (Li-air), or lithium-oxygen, batteries, researchers at the University of Cambridge have developed a lab-based demonstrator of such a battery. It is safe to say we still have another decade before we can begin to utilize such powerful batteries as scientists work to make sure it is stable enough for widespread use.

One step closer to the ‘ultimate battery’ – [Link]

LiFePO4 charger

DSC01725

Markus Gritsch shared his LiFePO4 charger project in the forum:

Since I really like using LiFePO4 AA and AAA batteries in some of my projects, I finally gave in and built a dedicated charger for them.
Previously I used a lab power supply to mimic the constant current/constant voltage charging curve, which worked also fine. But after seeing Patrick Van Oosterwijck nifty LiFePO4wered/USB™, I thought it would be a bit more convenient to charge these batteries using USB.

LiFePO4 charger – [Link]

Not a battery, not a cap: Murata’s small energy [storage] device

151001edne-murata-umac_pr_rev1.3

by Graham Prophet @ edn-europe.com:

To meet what the company sees as a gap in the available range of energy storage solutions, Murata has developed the UMAC, a small, high-capacity cylinder-type energy device for use in wearable and wireless sensor applications. Although lithium-ion based, Murata differentiates it from a battery.

The UMAC is a miniature device with a high energy storage capacity, low internal resistance, fast charging and discharging and the ability to withstand load fluctuations. It may be used as a secondary battery in the same way as a capacitor. The UMAC achieves better charge/discharge characteristics and has an extended cycle life superior to conventional batteries. Suited for use as a power supply for wearable devices or sensor nodes for wireless sensor networks, the UMAC maintains flat voltage characteristics while accommodating a wide range of load characteristics.

Not a battery, not a cap: Murata’s small energy [storage] device – [Link]

Power Management Solutions: Battery Chargers

Fig0128

Maurizio @ dev.emcelettronica.com writes:

Out of all portable devices, the most numerous are the mobile phones (Figure 1). Most of them feature Li-ion or Li-polymer accumulators and Freescale has a broad range of charger ICs dedicated to supporting all the phases of a complete recharge cycle. Generally speaking the charging of a mobile phone is performed by taking energy from:

a) from a wall outlet
b) from the USB port of a computer
c) from the 12V output of a vehicle

Power Management Solutions: Battery Chargers – [Link]

Charger interface IC avoids handset overheating at fast-charge rates

PI_ChiPhy_Sept_15

by Graham Prophet @ edn-europe.com:

Power Integrations offers a charger interface IC compatible with Qualcomm’s Quick Charge 3.0 specification; PI says its CHY103D IC optimises efficiency to prevent handset overheating during high-speed charging.

Added to the ChiPhy charger-interface IC family, PI saya this is the first IC for off-line AC-DC chargers compatible with the Quick Charge (QC) 3.0 protocol from Qualcomm Technologies. Used alongside Power Integrations’ InnoSwitch AC-DC switcher ICs, the CHY103D device incorporates all of the functions needed to support QC 3.0. The QC 3.0 protocol implemented in the CHY103D device substantially reduces losses in the smart mobile device handset during rapid charging. This permits system designers to choose to charge handsets faster or reduce phone touch-temperature during charging, and enhances the efficiency of the charging process.

Charger interface IC avoids handset overheating at fast-charge rates – [Link]

IC monitors multicell battery packs

Intersil ISL94203

by Susan Nordyk @ edn.com:

The ISL94203 battery-pack monitor IC from Intersil monitors, protects, and cell-balances three- to eight-cell rechargeable battery packs, supporting Li-ion CoO2, Li-ion Mn2O4, and Li-ion FePO4 chemistries. Its internal state machine has five preprogrammed stages that accurately control each cell of a battery pack to extend operating life.

In addition to functioning as a stand-alone battery-management system for rechargeable Li-ion battery packs, the ISL94203 can be used with an external microcontroller communicating via an I2C interface. The device integrates high-side charge/discharge FET-drive circuitry, which allows the battery pack to be securely ground referenced.

IC monitors multicell battery packs – [Link]