HYBRID VEHICLES
In a battery charging system for a hybrid vehicle, a user-operated switch is provided for triggering an engine to charge battery at an earlier stage for an extended journey as compared to a normal journey. A sensor is provided to detect a charge state level of the battery, the output of the sensor being compared at with a threshold set by switch.
1 . A method of operating a hybrid vehicle having an engine and a battery, comprising:
triggering the engine to charge the battery when a value of a battery variable falls below a predetermined threshold value during a normal journey; and
triggering the engine to charge the battery when the battery variable value falls below a higher threshold during a non-normal journey.
2 . The method according to claim 1 , wherein the non-normal journey is an arduous journey.
3 . The method according to claim 1 , wherein the non-normal journey is an extended journey.
4 . A method according to claim 1 , wherein the hybrid vehicle comprises a battery controller comprising a user-operated input control element adapted to receive the predetermined threshold value.
5 . A method according to claim 1 , wherein the predetermined threshold value is set before the normal journey.
6 . A method according to claim 1 , wherein the predetermined threshold value is set at least two discrete levels.
7 . A method according to claim 1 , wherein the predetermined threshold value is adjustable between two limit values.
8 . A method according to claim 1 , wherein the battery variable value is a state of charge of the battery.
9 . A method according to claim 1 , wherein the engine is controlled to charge the battery substantially throughout operation of the engine.
10 . A battery charging system for a hybrid vehicle, comprising:
a battery;
a battery variable sensor;
a comparator connected to the battery variable sensor and adapted to compare a current value of a battery variable with an adjustable threshold value; and
a battery charging device connected to the comparator and adapted to charge the battery when the battery variable falls below a currently-set threshold value.
11 . The system according to claim 10 , wherein the battery charging device is a generator driven by an internal combustion engine of the hybrid vehicle.
12 . The system according to claim 10 , wherein the battery variable is a state of charge of the battery.
13 . The system according to claim 10 , wherein the adjustable threshold value is set by a user-operated control element.
14 . The system according to claim 10 , wherein the adjustable threshold value is settable to at least two discrete levels.
15 . The system according to claim 11 , further comprising a separate user-operated control element adapted to cause the battery charging device to charge the battery at substantially all times of operation of the hybrid vehicle.