Selectively-enabling battery back-up power based on a power demand

A system comprising:

• a host device having a plurality of loads;
• and
• a back-up power subsystem to supply back-up power to the host device when a main power fails;
• wherein the host device is to designate a subset of loads of the plurality of loads that is to receive the back-up power when the main power fails, and communicate a number of loads in the subset of loads to the back-up power subsystem;
• and the back-up power subsystem includes:
• a battery module;
• and
• a back-up power control module to:
• determine a historical back-up power demand for the number of loads by averaging amounts of back-up power that were supplied during previous failures of the main power;
• determine an estimated back-up power demand of the host device by:
• when a historical back-up demand for the number of loads is unavailable, multiplying the number of loads by an estimated back-up power usage per load;
• and otherwise, use the historical back-up demand for the number of loads as the estimated back-up power demand of the host device;
• and
• selectively enable the battery module to output the back-up power to the subset of the plurality of loads of the host device, if the battery module has a power capacity greater than the estimated back-up power demand.

A method of providing back-up power from a battery module to a host device for a power loss event, comprising:

• determining an average back-up power demand of the host device having a quantity of loads based on a plurality of outputs of power from the battery module to the host device of a corresponding plurality of previous power loss events due to previous failures of a main power component supplying the plurality of loads;
• determining whether the quantity of loads has changed from one or more previous quantities of loads associated with the corresponding plurality of previous power loss events, and if so, resetting the average back-up power demand commensurate with the change in the quantities of loads in response to a current power loss event due to failure of the main power component supplying the quantity of loads, selectively enabling an output of power from the battery module to the quantity of loads of the host device if the battery module has a power capacity greater than the average back-up power demand
• determining the power capacity of the battery module, wherein determining the power capacity of the battery module comprises reducing an actual power capacity of the battery module by a margin percentage of the battery module commensurate with a tolerance percentage of the battery module based on current operating conditions of at least one of the host device and a system in which the host device operates;
• and
• comparing the average back-up power demand and the power capacity of the battery module to determine whether to disable or enable the output of power from the battery module.