Lucas Reed has a tutorial on how to build a boost converter using an Arduino.
Have you ever needed to power a project that’s not near an outlet? Have you needed to test using different voltages? Are you curious about analog circuits and power? Using Autodesk Circuits and a lead-acid battery, you can create a circuit that will act as a variable power supply, outputting a range of voltages from 5V to 20V.
Battery lifetime is a key consideration for the development of the wireless sensor nodes that will populate the Industrial Internet of Things (IIoT). In many applications, the sensor nodes will need to be installed in locations that are difficult to reach let alone service. The sensor nodes need to be autonomous in terms of energy because it is too costly and difficult to run power lines to them or to have maintenance workers replace batteries regularly.
Maximize the Energy from Long-Life Batteries – [Link]
The SparkFun Battery Babysitter is an all-in-one single-cell Lithium Polymer (LiPo) battery manager. It’s half battery charger, half battery monitor, and all you’ll ever need to keep your battery-powered project running safely and extensively.
The Battery Babysitter features a pair of Texas Instruments LiPo-management ICs: a BQ24075 battery charger and a BQ27441-G1A fuel gauge. The charger supports adjustable charge rates of up to 1.5A, as well as USB-compliant 100mA and 500mA options. It also features power-path management, guaranteeing power to your project even if the battery has died. The self-calibrating, I2C-based BQ27441-G1A measures your battery’s voltage to estimate its charge percentage and remaining capacity. It’s also hooked up to a current-sensing resistor, which allows it to measure current and power! It’s a handy IC to have, if you ever need to keep an extra eye on your project’s power draw.
The simplest model of a battery comprises an ideal voltage source that connects in series with a resistance whose value—often a few milliohms—depends on the battery’s electrochemical condition and construction. If you attempt to use an ordinary ac milliohmmeter containing a kilohertz-range ac excitation source to measure a battery’s internal resistance, you get erroneous results due to capacitive effects, which introduce losses. A more realistic battery model includes a resistive divider that a capacitor partially shunts (Figure 1). In addition, a battery’s no-load internal resistances may differ significantly from their values under a full load. Thus, for greatest accuracy, you must measure internal resistance under full load at or near dc.
Dynamic-load circuit determines a battery’s internal resistance – [Link]
Using Wi-Fi is a convenient way to link your newly created IoT device into your existing IT infrastructure – including cloud services – but it also has a drawback. Wi-Fi’s demand for power usually makes battery operation impractical for any real deployment. I have been able to get around this issue for most of my projects (e.g. the train and the smart shelf described on this blog) because they are for demonstration purposes only, requiring the battery to last no longer than a few hours.
The wearable and personal-electronics industries are booming. Devices in this market vary wildly by application and use. These multifunction devices are designed to help people in their daily activities and make their lives comfortable. They can be found in different shapes, colors, sizes, and safety measures. They may differ significantly from each other, but they all have one thing in common—the need for a battery and a battery charger. These portable devices are typically powered by batteries installed internal to the device, which must be charged efficiently and quickly on a regular basis. The user’s charging experience also needs to meet the requirement of safety, comfort, and convenience.
Battery-charging considerations for low-power applications [PDF] – [Link]
Researchers at the University of California (USA) have developed a nanowire-based material that allow a rechargeable battery to be charged and discharged hundreds of thousands of times without any loss of capacity. This would virtually eliminate the need to replace a battery made from this material during the lifetime of the device it powers.
Rechargeable batteries with nanowires last forever – [Link]
This is a small bench power supply that is powered by two lithium-ion batteries. The project was inspired by Dave Jones from EEVblog but the design is completely mine. The voltage range is 0-20V regulated in 10mV steps and maximum current is 1A with current limit set in 1mA steps.
The power supply runs on a linear voltage regulator built on discrete components. The design of the linear regulator was inspired by the user Amspire from the EEVblog forum. The basic idea is that the Q1 pass transistor and U5A op amp act in a classic voltage regulating loop. U5A gets feedback from the output voltage and acts on Q1 in such a way that the output voltage equals the reference voltage on the inverting input. U5D acts as a comparator and switches the base of Q1 low to set the output voltage to 0V. It acts as a current limiter which is quickly switching on and off the output to maintain the set current limit.
AmpStrike – Battery Powered Bench Power Supply – [Link]
Patrick Van Oosterwijck has published a LiFePO4 battery solution for Raspberry Pi that will also act as UPS power supply:
The project is built on top of a LiFePO4wered/USB module. A small board is added with an MSP430G2131 microcontroller that takes care of monitoring input and output voltage, monitoring a PCB touch button, driving a power indicator LED and switching the load (the Raspberry Pi power). The microcontroller is also connected to the Pi’s I2C bus and monitors the Pi’s running state. The small board connects to 8 of the Pi’s GPIO pins but leaves the rest free to allow prototyping using fly leads.
LiFePO4wered/Pi – LiFePO4 battery for Raspberry Pi – [Link]
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.