Housed in a low-profile 24-pin QFN package, the LTC4040 from Linear Technology is a 2.5-A lithium-battery–backup power-management system for 3.5-V to 5-V supply rails that must be kept active during a main power failure. The device uses an on-chip bidirectional synchronous converter to provide high-efficiency battery charging, as well as high-current, high-efficiency backup power.
When external power is available, the LTC4040 operates as a step-down battery charger for single-cell lithium ion or lithium iron phosphate batteries, while giving preference to the system load. When the input supply drops below the adjustable power-fail-input threshold, the LTC4040 operates as a step-up regulator capable of delivering up to 2.5 A to the system output from the backup battery. In the event of a power failure, the part provides reverse blocking and a seamless switchover between input power and backup power.
IC manages battery-backup systems – [Link]
Linear Technology has introduced a voltage supply regulator chip that includes an interface to take care of charging, balancing and monitoring external supercaps (or batteries) for system power backup. Its wide 0.1 V to 5.5 V capacitor/battery voltage and 1.8 V to 5.25V system backup voltage ranges make it suitable for a wide range of backup applications using supercapacitors or batteries. A proprietary low noise switching algorithm optimizes efficiency with capacitor/battery voltages that are above, below or equal to the system output voltage.
The LTC3110 can autonomously transition from charge to backup mode or switch modes based on an external command. Pin-selectable Burst Mode operation reduces standby current and improves light-load efficiency, which combined with a 1 μA shutdown current make the LTC3110 ideally suited for backup applications. Additional features include voltage supervisors for charge direction control, end of charge and a general purpose comparator with open-collector output for interfacing with a microcontroller.
Voltage regulator with backup management – [Link]
by Steve Taranovich @ edn.com
Any hobbyist can charge a battery quickly, but can you do it without an explosion, excessive heating or major degradation in battery cycle life?
Well many companies have managed fast charging techniques that typically use specialized algorithms. These algorithms take into account the chemistry of the battery and some sort of non-standard charging rate curve. Many device manufacturers and wireless operators are now providing a minimum two-year warranty on smart phone devices setting 800 cycles as the battery cycle life of the battery.
Charging batteries rapidly and safely – [Link]
TI’s new bq25890, bq25892, and bq25895 5A chargers with TI’s MaxCharge™ technology charge your mobile device faster while keeping your device cooler. The switch-mode chargers can charge a 1-S Li-Ion cell to 80% capacity in 30 minutes, while traditional devices only reach 30%. The I2C-controlled chargers’ high efficiency and thermal management result in the fastest, safest and coolest charging capability.
Key features and benefits
- Fast charging to high capacity battery with up to 5A high charging current
- Optimized for high voltage input: >91% charging efficiency at 3A with 9V input
- Innovative Input Current Optimizer (ICO) to maximize input power without overloading adapter
- Resistance compensation from charger output to cell terminal to enhance power delivery to battery
- Integrated ADC for charging system monitoring
Single-cell 5-A Li-Ion battery charger with MaxCharge™ technology – [Link]
This design is a battery management circuit, which involves the use of CAN/LIN interface. The system addresses the matter about managing rechargeable batteries. This design features an 8-output hardware configurable, high side/low switch with 16-bit serial input control using the serial peripheral interface (SPI). Two of the outputs are directly controlled using a microcontroller which are applicable in pulse-width modulation. The design also features high-speed CAN interface that is use to convert digital protocol information into an analog CAN communication.
The RD9Z1-638-4Li reference design is a Battery Management System (BMS) for 4-Cell Li-Ion battery applications featuring the MM9Z1_638 Battery Sensor Module. The RD9Z1-638-4Li is built to demonstrate the product capabilities in a 4-cell Li-Ion application where high EMC performance is required to obtain high accuracy measurements on key battery parameters. The board features an 8-pin standalone CAN transceiver to interface with others modules. Very high EMC robustness and performances are achieved by the Freescale MC33901 CAN High-Speed Transceiver. For cell balancing function and general purpose switches, the board features the Freescale MC33879 Configurable Octal Serial Switch.
The design is useful to automotive applications such as engine management, climate controls, communications and safety systems. The circuits function is suitable for a hybrid electric vehicle which monitors the condition of individual cells which make up the battery and maintains all the cells within the operating limits. It also provides information on the state of charge (SOC) and state of health (SOH) of the battery.
Intelligent 4-Cell Lithium Battery Management with CAN/LIN Interface – [Link]
by Steven Keeping @ digikey.com
The wearables market is booming. Statistics aggregator web portal Statista, notes that the global market will be worth over $7 billion this year and $12.6 billion by 2018.
Although the potential rewards are high, this is not an easy market to enter. Designing smart watches or fitness bracelets is tough; consumers expect lots of functionality, smartphone connectivity, compact form-factor, light weight, and long battery life. The introduction of highly integrated, ultra-low-power microprocessors and wireless chips has eased the design process, but squeezing out all of the battery’s power remains key to a wearable product’s success.
This article takes a look at how silicon vendors help wearables designers extend battery life by offering power-frugal displays, microcontrollers (MCU), silicon radios, and power-management chips designed specifically for ultra-low-power applications.
Extending Battery Life in Wearable Designs – [Link]
by TrackerJ @ instructables.com:
One of the main problem in battery powered projects is to choose/use the proper battery size/model/type. As market is flooded now with a lot of low quality batteries claiming thousands of mAh ( Ultrafire fakes stories is just an example) the only way to proper check them is to run a set of tests.
A simple basic tester that will be able to monitor over the entire battery lifetime at least few parameters like, voltage, current, power consumption and stored energy between charges can give you valuable informations about the parameters and health of the battery. And of course also you can see how are looking the numbers against the datasheet claims :).
ESP8266 WIFI Battery Monitor System – [Link]
12V Lead Acid Battery Monitor is a simple project which tells you the voltage of your Lead acid battery visually with the help of 10 LED’s. This project is based on the popular LM3914 IC from Texas Instruments.
The LM3914 senses the voltage level at the input pin and drives the 10 light emitting diodes based on the voltage detected on input connector. Circuit works on same battery, doesnt not require separate supply input. Jumper is used to select the DOT mode or bar graph mode.
12V Lead Acid Battery Voltage Monitor – [Link]
And it can be added that also simply and cheaply. MCP73831 from company Microchip is „all-in-one“ solution for charging a single Li-ion/Li-Po cell.
Li-Ion a Li-Polymer cells are becoming a No.1 choice for many applications, where they persuade by high energy density, low weight, low self-discharge and for majority of applications also by their favorable flat shape (Li-Po). Their price is also affordable (in regard to their properties) and so there´s usually only one “difficulty” – to solve charging, or more exactly – overall management of these cells. Basic principles were highlighted to you in our article “Try the most favourite types of batteries”. To reach a maximum cell lifetime, it´s also advisable to use initial (preconditioning) slow charging and also important is a proper charging termination as well as repeated recharging after reaching a certain degree of discharge.It´s obvious, that to construct such a circuit from discrete components would be possible, but impractical, bulky and expensive. That´s why there are various charging controllers on the market and in many cases a single chip solution is an ideal solution. This is also a case of MCP73831 chip – a fully integrated linear charging controller. If you use only a single cell and maximum charging current of 500mA is sufficient for you, then MCP73831 will meet all requirements for a quality and safe recharging solution. MCP73831 has integrated output (FET) transistor, current sensing and reverse discharge protection.
Charging current can be easily adjusted by a single resistor, what´s also associated with other parameters like preconditioning current and charging termination. MCP73831 also contains a thermal regulation, which decreases output current in case of increased chip temperature (for example because of higher ambient temperature).
MCP7383x is available in four versions with factory-set regulation (max. charging) voltage. In our store can be found “the safest” first version with 4.20V regulation voltage – MCP73831T-2ATI/OT. In datasheet (p. 25) we can also read that this is the “AT“ version, which starts repeated charging at 94% Vreg (i.e. at approx. 3.95V), in a SOT23-5 package. Supply voltage can be in a range of 3.75-6V, while in respect to a thermal stress of a chip it´s better to supply it by a voltage close to max. output voltage (4,20V).
The chip can be easily supplied by a standard 5V voltage, but in cases of increased risk of overheating (operation at higher ambient temperatures, densely populated PCB,…), a common Si diode in series can be helpful. This will decrease supply voltage in 0.6-0.7V (and takes a portion of thermal loss on itself).
Charging status can be found at the “Charge status output” pin, which can drive an indication LED or can be connected to a host microcontroller.
With MCP73831 you’ll charge lithium cells easily and safely – [Link]
This is a prototype model Battery (type C ) for electronic devices. The battery has the ability to be recharged by the sun and don’t need any battery charger. It is necessary for climbers, explorers, soldiers, free camping and general for humans who attempt in areas without infrastructure electricity. The standard can also be applied to other types of batteries and the current technology allows their development with much greater energy capacity.
Specifications of the prototype:
- Battery 1.2v 700 mAh
- Solar cell 1.5v 70mA
Solar self-rechargeable Battery – [Link]