A smart battery or a smart battery pack is a rechargeable

battery pack A battery pack is a set of any number of (preferably) identical Battery (electricity), batteries or individual battery cells. They may be configured in a series, parallel or a mixture of both to deliver the desired voltage and current. The term ' ...

with a built-in battery management system (BMS), usually designed for use in a

portable computer A portable computer is a computer designed to be easily moved from one place to another, as opposed to those designed to remain stationary at a single location such as desktops and workstations. These computers usually include a display a ...

such as a

laptop A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer scree ...

. In addition to the usual positive and negative terminals, a smart battery has two or more terminals to connect to the BMS; typically the negative terminal is also used as BMS "ground". BMS interface examples are: SMBus, PMBus, EIA-232, EIA-485, and

Local Interconnect Network LIN is a network protocol used for communication between components in modern vehicles. It is a low-cost single-step serial protocol that supports communications up to 19.2 Kbit/s with a maximum bus length of . History The need for a cheap seri ...

. Internally, a smart battery can measure voltage and current, and deduce charge level and SoH (State of Health) parameters, indicating the state of the cells. Externally, a smart battery can communicate with a smart battery charger and a "smart energy user" via the bus interface. A smart battery can demand that the charging stop, request charging, or demand that the smart energy user stop using power from this battery. There are standard specifications for smart batteries: Smart Battery System,MIPI BIF
and many ad-hoc specifications.

Charging

A smart battery charger is mainly a switch mode power supply (also known as high frequency charger) that has the ability to communicate with a smart battery pack's battery management system (BMS) in order to control and monitor the charging process. This communication may be by a standard bus such as

CAN bus A controller area network bus (CAN bus) is a vehicle bus standard designed to enable efficient communication primarily between electronic control units (ECUs). Originally developed to reduce the complexity and cost of electrical wiring in auto ...

in automobiles or System Management Bus (SMBus) in computers. The charge process is controlled by the BMS and not by the charger, thus increasing security in the system. Not all chargers have this type of communication, which is commonly used for lithium batteries. Besides the usual plus (positive) and minus (negative) terminals, a smart battery charger also has multiple terminals to connect to the smart battery pack's BMS. The Smart Battery System standard is commonly used to define this connection, which includes the data bus and the communications protocol between the charger and battery. There are other ''ad-hoc'' specifications also used.

Hardware

Smart battery controller

integrated circuits An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

are available. Linear Technology manufactures, such as the LTC4100, or the LTC4101, are Smart Battery System-compatible products.

Microchip Technology Microchip Technology Incorporated is a publicly listed American semiconductor corporation that manufactures microcontroller, mixed-signal, analog, and Flash-IP integrated circuits. Its corporate headquarters is located in Chandler, Arizona. ...

provides an application note for a smart battery charger based on the PIC16C73.direct link
The PIC16C73 source code is available for this application.

References

{{reflist Smart devices Rechargeable batteries Battery charging

Charging

Hardware

See also

References