As discussed before, for very large packs it is often necessary to decouple the gas gauge circuit from the protection circuit. For smaller and medium sized packs up to 4 cells in series, a single-chip solution that will provide the gauging and cell balancing functions along with pack protection can usually be provided. However for larger packs, this process becomes unwieldy and for the most part impractical because of the number of interconnections and high voltages involved. The gauging / coulomb counting function can be done at the pack level while the cell monitoring and balancing can be done with a separate, high voltage analog IC as is shown in the following diagram.