Overview

The Battery Interface (BIF) Specification has been defined to offer a cost-efficient and flexible communication interface solution between a mobile device Host and Battery Packs. The fundamental requirement for a battery interface is to provide a method to communicate battery characteristics information to ensure safe and efficient charging control under all operating conditions. The interface supports two battery types: an analog, low-cost battery interface that supports detection of battery chemistry and capacity for basic safety, and a digital smart battery interface with security features that can offer stronger protection against the use of counterfeit batteries and many functions for increased safety for mobile device end users. 

Scope

The smart battery interface supports multiple Slave devices within the Battery Packs or mobile device Host. The Specification defines the digital communication interface physical layer electrical requirements and characteristics, protocol and basic data architecture information for a mobile device Host and the Slaves in the Battery Pack with sufficient detail to allow development of the interface.

For Low Cost Battery Packs, in which only a pull-down resistor provides information about the Battery Pack, BIF specifies measurement range and accuracy. The specific measured resistor value assignment for capacity, chemistry etc. is left to the mobile device manufacturers. However, the range and accuracy are defined to comply with most of the low cost batteries already in the market.

Battery Pack insertion, presence and removal detection system is specified for both smart and low cost batteries. Any mechanical dimensions and properties like physical connector or battery form factors are outside the scope of this document. 

Purpose

Being the first complete battery communication interface standard for mobile devices, BIF simplifies both the Host and Battery Pack design while reducing development costs throughout the mobile battery ecosystem as a result of enabling use of a single interface over a wide range of mobile device products.

Battery chemistries are evolving rapidly and constantly present new challenges to charge control, battery life time prediction and other similar requirements. The BIF is designed to allow future expansibility and room for new innovative functions and services for product differentiation while respecting the MIPI DDB Specification and coexisting smoothly with other standards in mobile battery technology area.

Every effort has been made to enable a low cost solution in Battery Pack (Slave IC) and mobile device Host design without compromising compatibility or design choices and service content in the Slave ICs. 

 

 Battery Interface Smart battery pack and low cost battery pack diagrams