Temperature dependent charge algorithm

An apparatus for charging a rechargeable battery (102) comprising:

• a temperature sensor (160) configured to measure ambient temperature (T);
• and
• charging circuitry (120) in electrical communication with the temperature sensor (160), the battery (102), and a power source (110), the charging circuitry (120) configured to:
• initiate a charging session to charge the battery (102) at a constant charge current to a maximum battery voltage (Vbat_max) with power provided from the power source (110);
• obtain the ambient temperature (T) from the temperature sensor (160);
• obtain a charge termination time (tt) based on the ambient temperature (T);
• and
• terminate the charging session when the charge termination time (tt) is reached.

A charging system (100) comprising:

• a rechargeable battery (102) configured to provide power to electrical components of a device;
• a power source (110);
• and
• a charger (120) comprising charging circuitry (120) in electrical communication with the power source (110) and the battery (102) when the battery (102) is docked with the charging circuitry (120), the charging circuitry (120):
• obtaining an open circuit voltage of the battery (102) prior to a charging session when the battery (102) is docked with the charging circuitry (120);
• initiating the charging session to charge the battery (102) at a constant charge current to a maximum battery voltage (Vbat_max) with power provided from the power source (110), the charging session corresponding to one of a first charging strategy or a second charging strategy based on the obtained battery (102) open circuit voltage;
• obtaining an ambient temperature (T) measured by a temperature sensor (160) in communication with the charging circuitry (120);
• obtaining a charge termination time (ti) based on the ambient temperature (T);
• and
• terminating the charging session when the charge termination time (tt) is reached.