Battery pack with multiple secure modules

The present invention pertains to portable power supplies having removable and replaceable electrochemical cells. In particular, the invention pertains to power supplies employing multiple replaceable primary or secondary cells. A modularized power supply is presented employing individual electrochemical cells which are rendered inert when separated from a specified unlocking circuit. The cells are enclosed in a cell module having a disabling circuit which isolates the cell terminals and prevents release of significant cell energy. A switch in the disabling circuit is activated when the cell module is connected to the specified unlocking circuit in an external frame. The frame includes receptacles for receiving multiple modules, all of which must be connected before power is delivered to a host interface. The frame may include circuits and devices for monitoring the performance of the modules, for controlling cell charging and discharging, and protective elements to protect the modules and tray from aberrant conditions such as high temperatures, overcurrent, and similar events. By including these in the frame, fewer elements are required in the individual modules, reducing their complexity, weight and cost. The present concepts are embodied in both integrated power supplies and removable battery packs. Using thin rigid modules, a large flat battery pack is formed. The relatively smaller modules are less susceptible to damage from handling. This is particularly advantageous when the cell used in embodiments with a lithium ion, lithium ion polymer or similar cell having a potential for producing fires in the event of an internal short. Power supplies using both primary and secondary cells are provided.