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]
by Darren Quick @ gizmag.com:
Researchers at Stanford University have created a fast-charging and long-lasting rechargeable battery that is inexpensive to produce, and which they claim could replace many of the lithium-ion and alkaline batteries powering our gadgets today. The prototype aluminum-ion battery is also safer, not bursting into flames as some of its lithium-ion brethren are wont to do.
The prototype battery features an anode made of aluminum, a cathode of graphite and an ionic liquid electrolyte, all packed within a flexible, polymer-coated pouch. And unlike lithium-ion batteries, which can short circuit and explode or catch fire when punctured, the aluminum-ion battery will actually continue working for a short while before not bursting into flames.
Flexible, fast-charging aluminum-ion battery offers safer alternative to lithium-ion – [Link]
Lithium ion battery charger implementation using C8051F300 app note(PDF!) from Silicon Labs.
Driven by the need for untethered mobility and ease of use, many systems rely on rechargable batteries as their primary power source. The battery charging circuitry for these systems is typically implemented using a fixed-function IC to control the charging current/voltage profile.
The C8051F30x family provides a flexible alternative to fixed-function battery chargers. This application note discusses how to use the C8051F30x family in Li-Ion battery charger applications. The Li-Ion charging algorithms can be easily adapted to other battery chemistries, but an understanding of other battery chemistries is required to ensure proper charging for those chemistries.
App note: Lithium ion battery charger using C8051F300 – [Link]
The charging system for a portable device is not always given a high priority in design but it can have a major role in the battery life of the system and, properly optimized, can allow the use of a smaller battery pack than otherwise would be needed. Not only are compact battery-management controllers needed, but intelligence also needs to be deployed tactically to allow the power system to be correctly optimized. This article will look at the needs of the Li-ion chemistry in terms of charging and what techniques can be used to maximize energy delivery and storage and summarize key solutions available for that purpose.
Lithium-Ion Batteries Call for Multi-Cycle Support to Maximize Uptime – [Link]
The NEW Solar BMS charger for LiFePO4 or any other Li-ion battery and used for OffGrid House, RV or boats, with wireless datalogging.
Solar BMS (Solar Battery Management System)is a solar charge controller designed to replace the Lead Acid solar charge controllers most people use today in Offgrid, RV, Boats and multiple other applications with 12V and 24V systems. Solar BMS can be used with 3 up to 8 Lithium cells (any type) or supercapacitors. The new SBMS100 will have multiple improvements over the first generation SBMS4080 see further for details.
120A Solar BMS charger LiFePO4, Li-ion OffGrid,RV with WiFi – [Link]
by Colin Jeffrey @ gizmag.com:
Dendrites – thin conductive filaments that form inside lithium batteries – reduce the life of these cells and are often responsible for them catching fire. Scientists working at the Pacific Northwest National Laboratory (PNNL) of the US Department of Energy claim to have produced a new electrolyte for lithium batteries that not only completely eliminates dendrites, but also promises to increase battery efficiency and vastly improve current carrying capacity.
New electrolyte promises to rid lithium batteries of short-circuiting dendrites – [Link]
by T.K. Hareendran:
Here is a tried and tested sample circuit of a Li-Ion battery charger that can be used to charge any 3.7V Li-Ion battery using a 5VDC (USB, Solar Panel…) power supply. At the heart of the circuit is one microchip MCP73831, available in SOT-23-5 package. MCP73831 is a highly advanced linear charge management controller for use in space-limited, cost-sensitive applications. This IC employs a constant current/constant voltage charge algorithm with selectable preconditioning and charge termination.
3.7V Li-Ion Battery Charger Circuit – [Link]
Standalone Linear Li-Ion battery charger with thermal regulation in ThinSOT application note (PDF!) from Linear:
The LTC4054 is a single cell lithium-ion battery charger using a constant-current/constant voltage algorithm. It can deliver up to 800mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of ±1%. The LTC4054 includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only two external components. Furthermore, the LTC4054 is capable of operating from a USB power source.
App note: Standalone Linear Li-Ion battery charger with thermal regulation – [Link]
The bq2510x series of devices are highly integrated Li-Ion and Li-Pol linear chargers targeted at space-limited portable applications. The high input voltage range with input overvoltage protection supports low-cost unregulated adapters.
The bq2510x has a single power output that charges the battery. A system load can be placed in parallel with the battery as long as the average system load does not keep the battery from charging fully during the 10 hour safety timer.
The battery is charged in three phases: conditioning, constant current and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is exceeded.
BQ25101H – 250-mA Single Cell Li-Ion Battery Charger, 1mA termination, 75nA Battery leakage – [Link]
If you´re deciding whether it´s worth to use a backup battery, we bring you a few remarks why to go for it or not.
Lithium battery Xeno Energy with a lifetime of over 10 years and rules for their usage were brought to you in our article „10 years of operation for 1 battery?”. They´re usable as a “main” power source for low power consumption devices and the second main field of their usage is a power supply backup. In contrast to the smallest cells used for PC memories backup (BIOS) for example, the types, which we keep in stock feature capacity of several Ah and they´re also able to provide a relatively decent current. That enables to use such battery also for a real operation of the device (MCU) during the power supply dropout.
Probably the main reason why not to use a backup battery is a doubt about higher production costs of a given device. However, when we look at the sales price in our e-shop, we find, that common PCB types like for example XL-050F AX (LS14250CNA) or XL-060F AX (LS14500CNA) are available for the price of max. 4 Eur/pce. At the same time, using this type of batteries eliminates the need for a battery holder, charging chip, etc.
The newest contribution on the field of PCB lithium batteries in our stock is the type XL-210F/STD 5,5mm, what´s the disc with 33mm diameter and only 6.6mm height, with leads to be soldered to PCB (THT). Low profile enables usage even in slim devices and everywhere, where common cylinder types are not suitable.
Further information will provide you the Xeno short form catalogue as well as detailed datasheets of Xeno batteries. In the Xeno production portfolio can also be found special batteries with a higher pulse capacity and type for extra high temperatures -55 to +130°C.
Backup battery soldered directly to a PCB? – [Link]