Systems and Applications Based on Modular Battery Packs

Methods for monitoring parameters of a battery pack are disclosed. The battery pack include a trace unit, which includes one or more sensor to monitor various parameters of the battery pack. The monitored parameters may include current conditions, resale history, and/or use history of the battery pack. The monitored parameters are transmitted from the trace unit to a remote server and may be used to calculate a residual value of the battery pack. The trace unit may periodically transmit data related to parameters of the battery pack to the server. The data transmission frequency may be determined based on a command sent from the remote server to the trace unit. Data related to parameters of the battery pack may be written on a traceability chain. Each data entry of the traceability chain includes information related to the battery pack at a certain point of time.