Automatic state of charge management system for lithium-ion batteries

A spares cabinet for maintaining a state of charge of spare batteries, wherein the spares cabinet comprises:

• an enclosure configured to enclose one or more components;
• a plurality of batteries stored within the enclosure, wherein each of the plurality of batteries has a given state of charge;
• a charger configured to charge each of the plurality of batteries;
• a load configured to discharge each of the plurality of batteries, wherein the charger and the load are configured to charge or discharge each of the plurality of batteries to a storage or transportation state of charge;
• a controller configured to maintain each of the plurality of batteries at the storage or transportation state of charge by causing the charger or load to respectively charge or discharge one or more batteries from the plurality of batteries to a target state of charge for replacement of one or more batteries of an external system, wherein the target state of charge corresponds to a state of charge of remaining batteries of the external system;
• a multiplexor configured to electrically couple each of the plurality of batteries to the controller, wherein one battery of the plurality of batteries is coupled at a given time;
• and
• a human-machine interface coupled to the controller, wherein the human-machine interface is configured to receive one or more inputs for the controller and to display a current state of charge for each of the plurality of batteries, wherein the one or more inputs comprise the states of the charge of the one or more batteries of the external system.

A method for maintaining a state of charge of spare batteries, comprising:

• providing a system, comprising:
• a charger configured to charge a plurality of batteries,
• a load configured to discharge the plurality of batteries,
• a controller configured to maintain each of the plurality of batteries at a storage or transportation state of charge by causing the charger or load to respectively charge or discharge one or more batteries from the plurality of batteries to a target state of charge for replacement of one or more batteries of an external system, wherein the target state of charge corresponds to a state of charge of remaining batteries of the external system, and
• a multiplexor configured to electrically couple each of the plurality of batteries to the controller, wherein one battery of the plurality of batteries is coupled at a given time;
• disconnecting each of the plurality of batteries from the system, wherein each battery of the plurality of batteries has a given state of charge;
• reading one or more parameters of a battery from the plurality of batteries;
• and
• determining, based on the parameters, whether or not to charge or discharge the battery to a target state of charge.