When developing a larger battery pack, the specifications and requirements for the battery management electronics need to be considered carefully depending on the application. In cost-sensitive applications, sometimes just the minimum functionality of cell safety and protection is implemented. For systems where the pack service life is important, the battery management should include a cell balancing function to keep all the cells matched to each other and prolong the service life of the pack. Finally, the fuel gauging function is required for applications in which the end-user needs to know the state of charge and/or state of health of a battery. With smaller batteries as used in handheld portable products, all of the battery management functions can often be implemented in a single chip. However with large, multi-cell packs which require many interconnections, it can become complex to deal with all the interconnections on a single IC due to the complexity of routing on to a small PC board. Furthermore, the analog functions may require the IC to be operating at high voltages in large packs. The “intelligence” aspect of the fuel gauge, implemented within a microcontroller circuit, do not lend themselves to implementation in a high voltage device. Thus, for high cell count or large battery applications, it is common to separate the analog & high voltage functions from the digital & low voltage control functions instead of a single-chip battery management implementation.