Electronic modules in motor vehicles are reflashed without encountering errors due to insufficient electrical power becoming available during a reflashing. A server system stores a database of update files together with data corresponding to a respective current draw and a respective reflash time associated with the respective update files when applied in each respective vehicle. A vehicle sends pedigree information to the server system which then identifies relevant update files and corresponding current draw and reflash time data for the particular vehicle. The relevant update files and corresponding data are sent to the particular vehicle. A state of charge of a battery in the vehicle is determined. A depleted state of charge is estimated that would remain after applying a relevant update file. The update file is not applied if the estimated depleted state of charge is less than a predetermined state of charge.