ELECTRIC DEVICE AND METHOD FOR OPERATING AN ELECTRIC DRIVE

• US 20130257386A1
• Filed: 03/29/2013
• Published: 10/03/2013
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: FRIESE, Andreas, KYNAST, Andreas, KERN, Stefan, ZIPF, Philipp
• Granted Patent: US 9,525,295 B2
• Time in Patent Office: Days
• US Class Current: 320/136
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

In a method for operating an electric device, which includes a first storage battery pack, a second storage battery pack and an electrical load, no more than one storage battery pack is discharged at any given time to operate the load. In the process, the storage battery pack to be discharged is selected as a function of a temperature of the first storage battery pack and a temperature of the second storage battery pack and/or as a function of an internal resistance of the first storage battery pack and an internal resistance of the second storage battery pack.

Claims

1. A method for operating an electric device, the device having a first storage battery pack, a second storage battery pack and an electrical load, the method comprising:

discharging no more than one storage battery pack at any given time to operate the load; and

selecting the storage battery pack to be discharged at least one of;

i) as a function of a temperature of the first storage battery pack and a temperature of the second storage battery pack, and ii) as a function of an internal resistance of the first storage battery pack and an internal resistance of the second storage battery pack.

2. The method as recited in claim 1, wherein the storage battery pack having the lowest temperature is discharged.

3. The method as recited in claim 1, wherein a discharge of a storage battery pack is terminated when a temperature of the storage battery pack reaches a specified threshold value.

4. The method as recited in claim 1, wherein the first storage battery pack and the second storage battery pack are discharged in alternation, when the temperature of the first storage battery pack and the temperature of the second storage battery pack differ by less than a specified threshold value from each other.

5. The method as recited in claim 4, wherein a change between the first storage battery pack and the second storage battery pack takes place more frequently than once per minute.

6. The method as recited in claim 1, wherein the storage battery pack having lowest internal resistance is discharged if a required electrical output exceeds a specified threshold value.

11. The electric device as recited in claim 1, wherein the electric device has a third storage battery pack.

7. An electric device, having a first storage battery pack to supply the device with energy, and a second storage battery pack to supply the device with energy.

8. The electric device as recited in claim 7, wherein the device is configured to discharge no more than one storage battery pack at any given time to operate the load, and to select the storage battery pack to be discharged at least one of:

i) as a function of a temperature of the first storage battery pack and a temperature of the second storage battery pack, and ii) as a function of an internal resistance of the first storage battery pack and an internal resistance of the second storage battery pack.

9. The electric device as recited claim 8, wherein the device has a circuit system which is provided to switch between a supply via the first storage battery pack and a supply via a second storage battery pack.

10. The electric device as recited in claim 7, wherein the first storage battery pack and the second storage battery pack have different internal resistances.

12. The electric device as recited in claim 7, wherein the electric device is a lawn mower.