A system characterized by: a power conversion module; a data port; a controller to receive data from the data port; and a data store containing instructions that when executed by the controller perform operations to control the power conversion module, the operations comprising: executing instructions in a first portion of the data store during booting of the controller; executing instructions in a second portion of the data store after the controller has booted, wherein the instructions in the first portion and the instructions in the second portion can each be executed by the controller to control the power conversion module to maintain a power output to a load; receiving a signal from the data port indicating the instructions in the second portion are to be modified; receiving from the data port modified instructions to be stored in the second portion; and executing, in response to the signal, the instructions in the first portion to store the modified instructions in the second portion and to maintain a power output to a load during instruction loading operations; the system further comprising: a primary power source input port to provide power to the controller and a secondary power source input port to provide an alternative power source to the controller, and wherein the operations further comprise: monitoring a power received from the primary power source input port to determine presence or stability of AC power at the primary power source input port, and switching to power available from the secondary power source input if the AC power received is determined to be absent or unstable. a power conversion module; a data port; a controller to receive data from the data port; and a data store containing instructions that when executed by the controller perform operations to control the power conversion module, the operations comprising: executing instructions in a first portion of the data store during booting of the controller; executing instructions in a second portion of the data store after the controller has booted, wherein the instructions in the first portion and the instructions in the second portion can each be executed by the controller to control the power conversion module to maintain a power output to a load; receiving a signal from the data port indicating the instructions in the second portion are to be modified; receiving from the data port modified instructions to be stored in the second portion; and executing, in response to the signal, the instructions in the first portion to store the modified instructions in the second portion and to executing instructions in a first portion of the data store during booting of the controller; executing instructions in a second portion of the data store after the controller has booted, wherein the instructions in the first portion and the instructions in the second portion can each be executed by the controller to control the power conversion module to maintain a power output to a load; receiving a signal from the data port indicating the instructions in the second portion are to be modified; receiving from the data port modified instructions to be stored in the second portion; and executing, in response to the signal, the instructions in the first portion to store the modified instructions in the second portion and to maintain a power output to a load during instruction loading operations; the system further comprising: a primary power source input port to provide power to the controller and a secondary power source input port to provide an alternative power source to the controller, and wherein the operations further comprise: monitoring a power received from the primary power source input port to determine presence or stability of AC power at the primary power source input port, and switching to power available from the secondary power source input if the AC power received is determined to be absent or unstable. a primary power source input port to provide power to the controller and a secondary power source input port to provide an alternative power source to the controller, and wherein the operations further comprise: monitoring a power received from the primary power source input port to determine presence or stability of AC power at the primary power source input port, and switching to power available from the secondary power source input if the AC power received is determined to be absent or unstable. monitoring a power received from the primary power source input port to determine presence or stability of AC power at the primary power source input port, and switching to power available from the secondary power source input if the AC power received is determined to be absent or unstable.