Ultracapacitor generator start module

An energy storage system comprising at least one energy storage module for powering a generator start system, the at least one energy storage module comprising:

• one or more ultracapacitors;
• at least one electrical connection for charging and discharging the one or more ultracapacitors;
• and
• a plurality of positive temperature coefficient (PTC) thermistors disposed electrically in parallel for passively limiting a charge current of the one or more ultracapacitors based on an internal temperature of the energy storage module and passively distributing the charge current to the one or more ultracapacitors.

An energy storage module comprising:

• a housing structure;
• a plurality of ultracapacitors disposed within a cavity of the housing structure;
• at least one electrical connection for charging and discharging the plurality of ultracapacitors;
• and
• a plurality of positive temperature coefficient (PTC) thermistors disposed electrically in parallel for passively limiting a charge current of the plurality of ultracapacitors based on an internal temperature of the energy storage module.