Tag Archives: Battery

ATMEGA328 based Weather Station


Vlad @ denialmedia.ca has build a solar powered weather station based on ATMega328 microcontroller that is able to measure temperature, a humidity, and UV radiation and it uploads measurement on WeatherUnderground network. The data are send to the air using a 433MHz link. The sensors used are DHT22, ML8511, BMP180 and a TP4056 charger IC is used to charge the Li-Po battery from a solar cell.

ATMEGA328 based Weather Station – [Link]

Smart Battery Charger


gfwilliams @ instructables.com has build a smart battery charger that is able to individually charge each battery , automatically discharge them and give you an idea of their capacity. The charger is controlled by an Espruino Pico and results are displayed on a Nokia 5110 LCD display.

If you’re anything like me you’ll end up with a lot of rechargeable batteries, none of which end up being charged properly, and some of which turn out to be completely unusable. It’d be perfect if you had a low-power battery charger that you could leave on all the time, that would charge your batteries individually, automatically discharge them, and give you an idea of their real capacity. That’s what you’ll make in this tutorial!

Smart Battery Charger – [Link]

LTC4123 – Low Power Wireless Charger


Linear Technology Corporation introduces the LTC4123 to further expand its offerings in wireless battery charging. The LTC4123 combines a 30mW wireless receiver with a constant-current/constant-voltage linear charger for NiMH batteries, such as Varta’s power one ACCU plus series. An external resonant LC tank connected to the LTC4123 enables the IC to receive power wirelessly from an alternating magnetic field generated by a transmit coil.  Integrated power management circuitry converts the coupled AC current into the DC current required to charge the battery. Wireless charging with the LTC4123 allows for a completely sealed product and eliminates the need to constantly replace primary batteries. Zn-Air (Zinc-Air) detection allows applications to work interchangeably with both rechargeable NiMH batteries and primary Zn-Air batteries with the same application circuit. Both battery types can directly power a hearing aid ASIC without the need for additional voltage conversion. By contrast, a 3.7V Li-ion battery requires a step-down regulator in addition to the LTC4123’s functionality to power the ASIC.

LTC4123 – Low Power Wireless Charger – [Link]


Lithium-Ion Battery Warms Up, Operates In Subzero Temperatures


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?

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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’


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


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


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


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]