First Series Then Parallel Battery Pack System

• US 20170373512A1
• Filed: 02/20/2017
• Published: 12/28/2017
• Est. Priority Date: 06/21/2016
• Status: Abandoned Application

• Current Assignee: Chunyi Wang
• Original Assignee: Chunyi Wang
• Inventors: Wang, Chunyi
• Application Number:
  US15/437,138
• Publication Number:
  US 20170373512A1
• Time in Patent Office: Days
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

This present invention provides a packing scheme for battery cells, known as FSTP (First Serial Then Parallel). That is, when building a battery pack, first the battery cells are connected in serial to reach the required voltage, then the resulted battery strings are connected in parallel to reach the required capacity. A final battery pack is thus completed. This scheme possesses the following advantages: (1) Safety of the pack against catching fire is greatly improved by an order of magnitude, since each of every cell in the pack has been monitored; (2) Total cost is contained within acceptable level; (3) Cell strings can be easily switched out of the pack, resulting in removing faulted cells instantly without significantly impacting operation. And the costly active battery balancing becomes unnecessary.

Claims

1. A battery pack comprising:

a. two or more battery cells connected in series to form a battery string;

b. two or more battery strings connected in parallel, each battery string further comprising;

i. a switching relay; and

ii. an integrated sampling circuit provided as a string battery management system configured to;

1. monitor the voltage and temperature for each of the two or more battery cells;

2. measure current for the battery string;

3. record all faults;

4. calculate status of charge for the battery string;

5. calculate status of health for the battery string;

6. calculate status of power for the battery string;

7. calculate total voltage for the battery string; and

c. a main battery management system in communication with the two or more battery strings configured to;

i. communicate with the string battery management systems via a system controller area network bus;

ii. cut out faulty strings;

iii. calculate status of charge for the battery pack;

iv. calculate voltage for the battery pack; and

v. calculate current for the battery pack.

2. The battery pack of claim 1, wherein the switching relays of the two or more battery strings are disconnected when the battery pack is not in use.

3. The battery pack of claim 1, wherein the integrated sampling circuit can measure voltage with a 0.01-volt accuracy.

4. The battery pack of claim 1, wherein the string battery management system is a SoC (system on chip) or SiP (system in package) IC when R>

10 where R is the ratio of pack capacity over cell capacity.

5. The battery pack of claim 1, wherein the string battery management system is a printed circuit board when R<

10.