This circuit can produce an output of 3.3V and 1A current continuously for a voltage input varying from 2.5V to 4.2V. The LTC3441 is a high efficient buck boost converter which plays a vital role in portable instrumentation because of its fixed frequency operation. This circuit produces the output from a single Li-ion battery. Multiple cells can also be used within the specified range of input voltage.
Input(V): 2.5V DC to 4.2V DC
Output(V): 3.3V DC
Output load: 1A
2.5V-4.2V input to 3.3V output – 1A Buck Boost Converter using LTC3441 – [Link]
Brian Dipert discuss his experience replacing an iphone battery @ edn.com:
About a week ago, in preparing to run some errands, I plugged my iPhone 4S into the charger in my car so that I could stream Pandora while I drove. Oddly, a “this accessory may not be supported” message appeared on-screen; when I unplugged and re-plugged the iPhone to the charger, it didn’t reappear, so I didn’t think anything more of it … until a half hour later, when the iPhone again alerted me, this time with a “low battery” message.
Battery technologies of all chemistry are experiencing revolutionary changes nowadays. Nanotechnology is leading this revolution by yielding new battery technologies including but not limited to Tiny Supercapacitors and Li-ion batteries that never explode at any condition. But, it’s bothersome to make different chargers for different types of batteries. So, Microchip solved this problem by introducing a new hybrid PWM controller, MCP19124/5, that charges batteries of any chemistry.
The power of this charging device lies in the combination of an 8-bit PIC microcontroller and an analog PWM controller in one package. This mixed signal low-side PWM controller features individual analog PWM control loops for both current regulation and voltage regulation. It can be configured with separate feedback networks and reference voltages. Any voltage, current, temperature, or duration can be used to trigger a transition to a different charging profile.
Various types of batteries require different charging profile. So, the only way to charge all kinds of batteries with a single device is to simulate all the charging profiles. A user can set his/her desired profile with the help of two independent current and voltage control loops, along with variable reference voltage. Now let’s get to know more details about this versatile PWM controller IC.
The MCP19124/5 is a mid-voltage (4.5-42V) analog-based PWM controller with an integrated 8-bit PIC Microcontroller. There are two devices, the MCP19124 and MCP19125, where the last one has four I/O pins more than the first one. MPC19124 and MPC19125 are packaged in 24-lead QFN package and 28-lead QFN package respectively. It has following features:
Smooth, dynamic transitions from constant-current to constant-voltage operation
Dynamically adjustable output current and output voltage over a wide operating range
Wide operating voltage range: 4.5-42V
Analog peak-current mode Pulse-Width Modulation (PWM) control
Available fixed frequency (31 kHz to 2 MHz)
I2C communication interface
9 GPIO for MCP 19124 and 12 GPIO for MCP19125
Integrated high voltage linear regulator, with external output
Integrated temperatures sense diode
Integrated 10 bit A/D converter
Minimal external components needed
Custom algorithm support
Topologies supported include Boost, SEPIC, Flyback, and Cuk
In fact, the above list is just a brief overview. The controller is so complicated that user must read all 236 pages of the datasheet to gain sufficient knowledge.
Now, the question is, how can we use this IC to design an efficient battery charger?
To find the answer, one must read the datasheet thoroughly. At the same time, in-depth knowledge about the target battery is also required. However, Microchip provided a few schematics (as references) in the datasheet based on different applications. The circuit on battery charger is given below:
This ultimate powerful dual-loop PWM controller is going to be a game changer and part of the battery technology revolution. It possesses lots of possibilities. To learn more about this fantastic hybrid controller, study the datasheet carefully.
Battery anxiety is a modern day problem for many of us. Mobile phone and wearable technologies are getting developed rapidly, but battery issues seem to be neverending. As phones and wearables are getting thinner, there needs to be a trade-off between battery life and design. Scientists are searching for a way to make a battery that’s tiny yet capable of holding the charge for a long time. So, what’s the solution? Supercapacitor.
Scientists have been researching on the use of nanomaterials to improve supercapacitors that could enhance or even replace batteries in electronic devices. But it’s not an easy task. Considering a typical supercapacitor, it must be a large one to store as much energy as a Li-ion battery holds.
To tackle the battery issue, a team of scientists at the University of Central Florida (UCF) has created a tiny supercapacitor battery applying newly discovered two-dimensional materials with only a few atoms thick layer. Surprisingly, the new process created at UCF yields a supercapacitor that doesn’t degrade even after it’s been recharged/discharged 30,000 times. Where a lithium-ion battery can be recharged less than 1,500 times without significant failure.
So, what else makes the supercapacitor special apart from their tiny size? Well, let’s hear it from Nitin Choudhary, a postdoctoral associate who conducted much of the research :
If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week.
Supercapacitors are not used in mobile devices for their large size. But the team at UCF has developed supercapacitors composed of millions of nanometer-thick wires coated with shells of two-dimensional materials. A highly conductive core helps fast electron transfer for fast charging and discharging. And uniformly coated shells of two-dimensional (2D) materials produce high energy and power densities.
Scientists already knew 2D materials held great promise for energy storage purpose. But until the UCF developed the process for integrating those materials, it was not possible to realize that potential. Nitin Choudhary said,
For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density, and cyclic stability.
Supercapacitors that use the new materials could be used in phones, wearables, other electronic gadgets, and electric vehicles. Though it’s not ready for commercialization yet. But the research team at UCF hopes this technology will soon end the battery problem of smartphones and other devices. So let’s wait awhile, and at the end of this year maybe you’ll be using a new smartphone that can be charged in seconds and lasts for a week, who knows!
Lithium-ion batteries are very popular as they’re lightweight and have high energy density. But at the same time, li-ion batteries are very sensitive to overcharge/over discharge. An internal short circuit can cause fire and it may even lead to a violent explosion. Fortunately, nanotechnology found a way to prevent this kind of nightmare. How? let’s discuss:
Why Does li-ion Battery Explode?
When a device draws too much power from a Li-Ion battery, it heats up and thus melts the internal separator between the two flammable electrolytes. This phenomenon ignites a chemical reaction between the electrolytes causing them to explode. Once their package ruptures, the oxygen in the surrounding air helps the flammable electrolytes to catch fire. The fire then spreads quickly to other cells and loads a thermal runaway.
During a thermal runaway, the high heat of the damaged or malfunctioning cell can propagate to the next cell, causing it to become completely thermally unstable as well. In some worse cases, a chain reaction occurs in which each cell disintegrates at its own timetable.
So, in a nutshell, Li-ion cells possess the potential of a thermal runaway. The temperature quickly rises to the melting point of the metallic lithium and cause a violent reaction, which finally causes an explosion.
How Can Nanotechnology Prevent This?
Recently conducted research shows that atomic layer deposition (ALD) of titania (TiO2) and alumina (Al2O3) on Ni-rich FCG NMC and NCA active material particles could substantially improve Li-ion battery’s performance and allow for increased upper cutoff voltage (UCV) during charging, which delivers significantly increased specific energy utilization.
A company called Forge Nano claims to prevent this thermal runaway situation by never letting it get started even if the battery electrodes are shorted out. Forge Nano’s precision coatings on cathode and anode powders protect against the most common degradation mechanisms found in Li-ion batteries.
The benefits of Forge Nano precision coatings include extended battery life and greater safety, especially in extreme situations such as high-temperature operation, fast cycling rates, and overvoltage conditions.
By implementing lithium-based ALD films in nanostructured 3D lithium-ion batteries, significant gains in power density, cycling performances during charge/discharge, and safety is noticed.
What’s the Result?
Some of Forge Nano’s accomplishments in the Li-ion battery space includes:
Increased lifetime of commercial cathode material by as much as 250%
15% higher energy density in large format pouch cells (40 Ah) that pass nail penetration testing
60% reduced gas generation in cathode material
A low-cost high-voltage cathode powder with exceptional performance
Increased rate capability of conventional materials for enhanced fast charge acceptance using Forge Nano’s proprietary solid electrolyte coatings
Since the solution found by the research, Forge Nano has been working on a commercial version of the product that they finally believe they can place in the market very soon.
A new prototype of a lithium-sulphur battery – which could have five times the energy density of a typical lithium-ion battery – overcomes one of the key hurdles preventing their commercial development by mimicking the structure of the cells which allow us to absorb nutrients. @ cam.ac.uk
This gets us a long way through the bottleneck which is preventing the development of better batteries.
Next-generation smartphone battery inspired by the gut – [Link]
Steve Taranovich discuss about various ways to enhance Li-Ion batteries safety.
Typically, Lithium-ion batteries are safe and reliable. Just think about the $28B market they had in 2013 with a relatively small amount of fires and explosions. But every fire and explosion incident has the potential to cause a loss of life or serious personal injury (Not to mention the collateral material damage and cost).
Lithium-ion battery fires: 7 solutions for improved safety – [Link]
A new type of batteries called “Printable Solid-State (PRISS) Lithium-Ion Batteries” was designed by a group of researchers from the Ulsan National Institute of Science and Technology (UNIST, South Korea). The new battery is created from consecutive layers of printed composite materials.
With a simple stencil printing process followed by ultraviolet cross-linking, a solid-state composite electrolyte (SCE) layer and SCE matrix-embedded electrodes are consecutively printed on arbitrary objects of complex geometries, eventually leading to fully integrated PRISS batteries. Then the rheological properties of SCE paste and electrode slurry adjusted to get thixotropic fluid characteristics, along with well-designed core elements.
This technology yields many positive features, it eliminates the need for conventional microporous separator membranes and the extra processing steps of solvent drying and liquid-electrolyte injection.
With this new type of batteries, unlimited forms and sizes of batteries will be available for our various projects.
David Jones has another useful video tutorial about how to safely charge Lithium Ion and Lithium Polymer batteries with a bench power supply. The purpose of this tutorial is to learn how to use your lab power supply to charge your Lithium Ion battery when you don’t have a special charger circuit to do so.
He used NCR18650B in his tutorial, a 3.6V 3400mAh Lithium Ion battery from Panasonic.
David warned us that charging this type of battery is quite dangerous if we didn’t do it in the correct way. Even with the presence of protection circuit in Lithium Ion battery.
You can find the charging diagram in NCR18650B battery datasheet.
According to the datasheet, the charging current is 1625mA and the charging voltage is 4.2V. Charging consists of two stages, first one is the constant current stage where you must supply a 1625mA constant current and when the battery voltage reaches 4.20V, the second stage starts, which is the constant voltage stage. In this stage, the current will naturally drop down, and the cutoff is typically about 10% of charging current so it’s about 170mA.
This tutorial applies to all Lithium Ion and Lithium Polymer batteries not only NCR18650B.
You can perform this 2-stage charging using your power supply, but it must supports CC(Constant Current) and CV(Constant Voltage) modes. You can read the following Q&A in electronics.stackexchange to learn what constant current and voltage modes mean. You can build a power supply with CC and CV modes for yourself if you don’t have a budget to buy a ready made one.
David said that using this type of float charging/trickle charging is not recommended, because it will build-up or plate the metallic parts inside the battery. So It’s better to use dedicated ICs designed for the float charging.
LTC4013 is a highly integrated, high voltage multi-chemistry synchronous step-down battery charger controller. With a wide input voltage range that spans up to 60V, the LTC4013 uses temperature-compensated 3- and 4-stage charge algorithms to efficiently charge 12V and 24V lead-acid batteries. By Graham Prophet @ edn-europe.com
Alternatively, the LTC4013 will charge a multicell Lithium-based battery stack with float voltages near to the input supply. Mode pins define the float voltage and charge algorithm. Charge current is precision regulated to ±5% and programmable with a single resistor up to 20A (depending on the selection of external components). The LTC4013 features user-adjustable maximum power point tracking (MPPT) circuitry that enables simple power optimization in the case of power-limited sources such as solar panels. The MPPT open-circuit method corrects for panel temperature changes without the inconvenience of adding a solar panel temperature sensor. Applications include portable medical instruments, monitoring equipment, battery backup systems, industrial handhelds, industrial lighting, military equipment, ruggedized notebooks/tablet computers, plus remote powered communication and telemetry systems.
60V-input battery charger; Pb-acid & Li-ion charge algorithms up to 20A – [Link]