The options to do system-side gas-gauging for a 4-series-cell Li-ion pack are limited. The smallest-size solution involves a single-cell gauge plus resistive divider, opamp buffer and LDO, per SLUA496. There are quite a few 4-cell gauges for pack-side applications, but I assume that they get confused if they suddenly see a new battery pack due to a pack swap. How big a problem is this, and are there workarounds? I imagine this question has been addressed before, but I can't find threads which do so. Thanks.