Precision battery pack circuits

• US 20080090139A1
• Filed: 10/12/2006
• Published: 04/17/2008
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: Younicos Inc. (Aggreko Ltd.)
• Original Assignee: Xtreme Power
• Inventors: Coe, Carlos, Hurst, Aeron, Hood, Mark
• Granted Patent: US 7,808,131 B2
• Time in Patent Office: Days
• US Class Current: 429/156
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack connection scheme is shown that provides an synchronized DC environment for every cell in the pack, such that every cell in the same or similar voltage level in the pack sees exactly the same voltage and current environment. In some embodiments, a pack is provided having a positive load connection terminal and multiple batteries connected in parallel to the terminal. The connections are made via respective conductive paths each including a high-power DC precision cable segment, each of the conductive paths having a resistance suitable to allow an average charge acceptance rate of the battery pack to be greater than a one-hour, or “C1”, charge rate. The precision cable segments preferably have matching impedances, or have matching DC resistances.

Claims

1. A battery pack capable of supplying at least 50 amps of current, the battery pack comprising:

a positive load connection terminals; and

multiple batteries each having an anode and a cathode, the cathodes of the batteries connected in parallel to the positive load connection terminal via respective and distinct conductive paths, each conductive path having an under-load resistance differing from an under-load resistance of each other path by less than about 1 milli-ohm.

2. The battery pack of claim 1 wherein the conductive paths each include a respective cable and a respective portion of a solid terminal bus connecting the cables and the load connection terminal.

3. The battery pack of claim 2 wherein the cables are attached to the terminal bus at cable terminals equally spaced from the load connection terminal.

4. The battery pack of claim 3 wherein the cable terminals are disposed on a circle having the load connection terminal coupled at its center.

5. The battery pack of claim 1 further comprising a negative terminal bus, the anodes of the multiple batteries being connected in parallel to the negative terminal bus via multiple second conducive paths all having identical electrical lengths.

6. The battery pack of claim 1 wherein the multiple batteries have resistance properties as closely as possible matching each other.

7. The battery pack of claim 1 wherein the multiple batteries have charge-acceptance properties as closely as possible matching each other.

8. The battery pack of claim 1 wherein the multiple batteries each have an impedance (under load) of less than about 50 milli-ohms.

9. The battery pack of claim 1 wherein the multiple batteries each has a similar loaded output impedance, the first conductive paths each having a loaded series impedance at least five times greater than the loaded output impedance of the multiple batteries.

10. The battery pack of claim 1 further comprising a positive power cable having a first end and a second end, the first end connected to the positive terminal bus such that a similar resistance may be measured from the second end of the positive power cable to the cathodes of each of the multiple batteries.

11. The battery pack of claim 10 wherein the positive terminal bus comprises a round conductive piece having a center, the positive power cable being connected to the round conductive piece at the center.

12. The battery pack of claim 1 wherein the multiple first conductive paths each comprise a precision DC cable.

13. The battery pack of claim 12 wherein the multiple first conductive paths each comprise a solder joint connecting each precision DC cable to its respective battery cathode, each of the solder joints having a solder joint resistance value precision matched to that of the other solder joint(s).

14. A battery pack comprising:

a positive load connection terminal; and

first multiple batteries each having an anode and a cathode, the cathodes of the first multiple batteries connected in parallel to the positive load connection terminal via respective conductive paths each including a respective high-power DC precision cable segment, each of the conductive paths having a resistance suitable to allow an average charge acceptance rate of the battery pack to be greater than a C1 charge rate.

15. The battery pack of claim 14 further comprising a second set of multiple batteries connected in parallel with each other and connected in series with the first set multiple batteries, wherein the second set of multiple batteries are connected in parallel to each other with precision conductive segments each having equal resistance.

16. The battery pack of claim 14 wherein each conductive path has a loaded impedance characteristic and a loaded amperage capacity characteristic, the ratio of the loaded amperage capacity (in amps) to the loaded impedance (in ohms) being at least 1000 to 1.

17. The battery pack of claim 14 wherein each conductive path has a loaded impedance characteristic and a desired operating amperage characteristic, the ratio of the desired operating amperage (in amps) to the loaded impedance (in ohms) being at least 1000 to 1.

18. The battery pack of claim 14 wherein each conductive path having an under-load resistance differing from an under-load resistance of each other path by less than about a 5% tolerance.

19. The power supply module of claim 14 wherein the conductive paths each have an operating resistance matched as closely as possible to an operating resistance of the other conductive paths.

20. The power supply module of claim 19 wherein the conductive paths each as an operating inductance matched as closely as possible to an operating inductance of the other conductive paths.

21. The battery pack of claim 14 wherein the conductive paths each include a respective portion of a solid terminal bus connecting the precision cable segment and the load connection terminal.

22. The battery pack of claim 21 wherein the precision cable segments are attached to the terminal bus at cable terminals equally spaced from the load connection terminal.

23. The battery pack of claim 22 wherein the cable terminals are disposed on a circle having the load connection terminal at its center.

24. The battery pack of claim 21 wherein the solid terminal bus comprises silver-plated soft copper.

25. The battery pack of claim 14 wherein the precision cable segments have matching lengths.

26. The battery pack of claim 14 herein each conductive path is capable of carrying charge current of at least 5 amps.

27. The battery pack of claim 14 wherein the precision cable segments are connected to the positive load connection terminal with precision-matched connections.

28. The battery pack of claim 27 wherein the precision-matched connections comprise low-resistance solder connections.

29. A power supply system comprising:

a positive load connection terminal;

a negative load connection terminal;

multiple ranks of batteries, the ranks connected in series with first precision low-impedance conductors, each of the multiple ranks comprising;

multiple batteries connected in parallel with second precision low-impedance conductors;

wherein there is a most negative rank of the multiple ranks having battery anodes connected in parallel to the negative load connection terminal via respective first conductive paths, each conductive path having an under-load resistance differing from an under-load resistance of the other paths by less than about a 1% tolerance;

wherein there is a most positive rank of the multiple ranks having battery cathodes connected in parallel to the positive load connection terminal via respective second conductive paths, each conductive path having an under-load resistance differing from an under-load resistance of the other paths by less than about a 1% tolerance.