Electronic control module for a lithium-ion battery powered lantern

• US 7,737,655 B1
• Filed: 07/26/2006
• Issued: 06/15/2010
• Est. Priority Date: 07/26/2006
• Status: Expired due to Fees

• Current Assignee: Koehler-Bright Star Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: Koehler-Bright Star Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Devaney, John P., Dirsa, Mark
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Berhanu; Samuel
• Application Number:
  US11/460,051
• Time in Patent Office: 1,420 Days
• Field of Search: 320/106, 320134-136, 320/150
• US Class Current: 320/106
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/633 characterised by algorithms, flow charts, software details or the like
• CPC Class Codes: H01M 10/637 characterised by the use of reversible temperature-sensitive devices, e.g. NTC, PTC or bimetal devices; characterised by control of the internal current flowing through the cells, e.g. by switching means for preventing undesired use or discharge H01M50/572
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H05B 35/00 Electric light sources using a combination of different types of light generation
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 47/25 Circuit arrangements for protecting against overcurrent
• CPC Class Codes: H05B 47/28 Circuit arrangements for protecting against abnormal temperature
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A controller allows use of a battery protection circuit that limits electrical current to a safe level regarding short circuits and hazardous locations as well as determining each battery configuration having a voltage-temperature profile associated with that enhances cold weather operation; high battery temperatures are also detected and then rectified by the controller.

Claims

1. In an electronic control module for a battery for a light source, a method of regulating battery power comprising:

a) initializing the controller;

b) providing an initial low current to the light source;

c) testing the battery voltage for an initial low battery condition;

d) testing for a shorted condition of the light source;

e) determining a type of the battery connected to the light source;

f) determining a low battery voltage based on the battery type;

g) determining if the battery temperature is below a preset level;

h) if the battery temperature determined in step g) is below the preset level, conducting the additional steps of;

i. calculating a warm-up rate for the type of battery based on the battery temperature; and

ii. increasing battery current gradually based on the calculated warm-up rate as the battery warms up due to current flow through an internal resistance of the battery;

i) determining if the battery voltage is above the low battery voltage;

j) providing a full battery current to the light source if the battery voltage is above the low battery voltage.

2. The method of regulating battery power of claim 1, wherein the controller further comprises at least one input-output (I/O) pin, an analog-to-digital (A/D) converter, a clock, a timer and static random access memory (SRAM) and the step of initializing the controller further comprises the steps of:

a) selecting either and input or output function for all I/O (input/output) pins;

b) initializing the A/D converter by selecting the I/O pins that are to be used for analog inputs;

c) selecting the clock to be used to run the A/D converter and then enabling the A/D converter;

d) erasing all locations in SRAM;

e) initializing the timer parameters so that it will cause an interrupt every millisecond; and

f) enabling the interrupts.

3. The method of regulating battery power of claim 1 wherein the step of testing the battery voltage for an initial low battery condition further comprises:

a) obtaining an initial voltage reading from the battery;

b) comparing the initial voltage reading with a stored value;

c) determining if said initial voltage is less than the stored value;

d) turning off the light source if voltage is below the stored value and performing steps a)-c) until initial voltage rises above the stored value; and

e) applying the voltage to the light source when above the stored value.

4. The method of regulating battery power of claim 1 in a light source haying a switch and signal LEDs, comprising the additional steps after conducting the initial low battery voltage test of determining whether said switch is moved a position to actuate the LEDs, determining whether the LEDs should flash and setting a program control flag in an interrupt to evoke blinking.

5. The method of regulating battery power of claim 1 further comprising the step of illuminating a low battery indicator if the battery voltage determined in step i) is below the low battery voltage.

6. The method of regulating battery power of claim 1 wherein step f) is also based on the battery temperature.

7. The method of regulating battery power of claim 1 wherein step b) includes alternatively turning the light source on and off with amount of time that the light source is turned off being reduced to zero as the light source warms up.

8. The method of regulating battery power of claim 1 wherein step h) ii. includes alternatively turning the light source on and off with amount of time that the light source is turned off being reduced to zero as the battery warms up.

9. An electronic control module for regulating a battery for a light source, the control module programmed to perform the steps of:

a) initializing the controller;

b) providing an initial low current to the light source;

c) testing the battery voltage for an initial low battery condition;

d) testing for a shorted condition of the light source;

e) determining a type of the battery connected to the light source;

f) determining a low battery voltage based on the battery type;

g) determining if the battery temperature is below a preset level;

h) if the battery temperature determined in step g) is below the preset level, conducting the additional steps of;

i. calculating a warm-up rate for the type of battery based on the battery temperature; and

ii. increasing battery current gradually based on the calculated warm-up rate as the battery warms up due to current flow through an internal resistance of the battery;

i) determining if the battery voltage is above the low battery voltage;

j) providing a full battery current to the light source if the battery voltage is above the low battery voltage.

10. The electronic control module of claim 9 wherein testing the battery voltage for an initial low battery condition includes:

i. obtaining an initial voltage reading from the battery;

ii. comparing the initial voltage reading with a stored value;

iii. determining if said initial voltage is less than the stored value;

iv. turning off the light source if voltage is below the stored value and performing steps a)-c) until initial voltage rises above the stored value; and

applying the voltage to the light source when above the stored value.

11. The electronic control module of claim 9 further comprising the step of illuminating a low battery indicator if the battery voltage determined in step i) is below the low battery voltage.

12. The electronic control module of claim 9 wherein step f) is also based on the battery temperature.

13. The electronic control module of claim 9 wherein step b) includes alternatively turning the light source on and off with amount of time that the light source is turned off being reduced to zero as the light source warms up.

14. The electronic control module of claim 9 wherein step h) ii. includes alternatively turning the light source on and off with amount of time that the light source is turned off being reduced to zero as the battery warms up.