A battery monitoring system for simultaneously managing the batteries in 100 or more remote locations, each with 100 or fewer cells, has an individual battery monitor operatively engaged with at least one of the cells, a network access module in communication with the battery monitor, and a battery manager that has a fixed IP address that can be connected via an M2M data protocol to the battery monitor. The network access module is programmed to periodically transfer battery monitor data, including ohmic measurements, to the battery manager at a frequency of not less than once per week and with a total rate of data transfer of not more than 1 Mb per month. When the network access module initiates contact with the battery manager, the M2M data communication protocol assigns a variable IP address to the modem of the network access module.