A battery management system includes thermal batteries, sensors, a clock, a processor, and memory storing a data structure, and is configured to receive energy parameters and time data, calculate a rate of energy usage of the thermal batteries based on the received data, and execute battery commands to activate or disable selected thermal batteries. Energy usage data can be stored as individual data points over time, and battery commands can be received from an external computer. The system determines when to activate a second battery based on a predetermined threshold of estimated electrical energy of a first thermal battery. A battery management method includes receiving signals for voltage, current, temperature, and time duration, estimating electrical energy based on these parameters, and activating a second battery when the estimated energy falls below a predetermined threshold.

A receptacle in the body of a missile includes a plurality of electrical contacts connected to one or more electrically powered devices within the missile and configured to connect to an electrical power source. The receptacle receives a removable and reusable battery pack including connectors contacting the plurality of electrical contacts when the battery pack is mounted within the receptacle and one or more non-chemical, squibless batteries, preferably comprised of high power density primary cell lithium metal oxide cells. An interface circuit coupled to the squibless batteries initiates, terminates, and re-initiates delivery of electrical power from the squibless batteries to the plurality of electrical contacts based on a control input. Transportation, storage, and use risks associated with squibs in chemical batteries are avoided. During development testing, battery power may be shut down and restarted without the battery first becoming fully depleted and replaced shortening overall testing time and reducing expense.

For each cell in a plurality of cells from a same manufacturing run, a first and a second cell characteristic are received in order to obtain a plurality of cell characteristics. For each cell, a batch compatibility number that is associated with a number of compatible cells that that cell is compatible with is determined based at least in part on the plurality of cell characteristics. The plurality of cells is sorted according to the batch compatibility numbers to obtain a sorted list of cells. A plurality of compatible cells to include in a battery is selected from the plurality of cells, including by evaluating the plurality of cells according to the order of the sorted list of cells and beginning with the lowest batch compatibility number.

A power management unit architecture including a set of batteries connected to a load via a bus; a controller in operative communication with the batteries; a telemetry unit in operative communication with the controller and the batteries; at least one power switch in operative communication with the controller, the batteries and the bus; a squib unit operatively connected to the batteries; wherein the controller is configured to pull a battery current from a first battery and drive the first battery current into a second battery responsive to a predetermined current.

For each cell in a plurality of cells from a same manufacturing run, a first and a second cell characteristic are received in order to obtain a plurality of cell characteristics. For each cell, a batch compatibility number that is associated with a number of compatible cells that that cell is compatible with is determined based at least in part on the plurality of cell characteristics. The plurality of cells is sorted according to the batch compatibility numbers to obtain a sorted list of cells. A plurality of compatible cells to include in a battery is selected from the plurality of cells, including by evaluating the plurality of cells according to the order of the sorted list of cells and beginning with the lowest batch compatibility number.