LeftieBiker wrote:The individual cells get out of balance - they have different voltages, and when the imbalance gets large enough it lowers range, because the BMS perceives low battery conditions based on the SOC of the lowest cell(s).
Yes. Also the BMS perceives full battery condition by the voltage of the highest cell. An out of balance battery pack stores less energy.
LeftieBiker wrote: Balancing only happens at 100% charge with lithium packs, a process known as "Top Balancing."
Top balancing isn't the only option for lithium packs. For uses other than cars, balancing the pack at the bottom can be preferred. There are also methods for using the unbalanced energy in the pack for real usage, often called "dynamic balancing". These methods have the potential for extending pack life and making the system more efficient.