Protection of a battery against an extended chargeless period

Patent metadata

Field	Value
Publication number	US-10326188-B2
Application number	US-201514724168-A
Country	US
Kind code	B2
Filing date	May 28, 2015
Priority date	Jun 17, 2014
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

An assembly of batteries includes a first battery and a second battery electrically connected in parallel. The first battery is configured to deliver a battery capacity in a first power supply voltage range. The second battery is configured to deliver a battery capacity in a second voltage range. An upper limit of the second voltage range is set between upper and lower limits of the first voltage range. In an operating system, if supplied battery power falls below a threshold, the parallel connected first and second batteries are disconnected from the load.

First claim

The invention claimed is:

1. An apparatus, comprising:
a first battery delivering battery voltage to a load in a first voltage range, the first voltage range having an upper limit and a lower limit, wherein operation of the first battery below the lower limit results in damage to the first battery; and
a second battery, directly electrically connected in parallel with the first battery, delivering a battery voltage in a second voltage range; and
a comparator comparing a voltage across the parallel connected first battery and the parallel connected second battery to a threshold, and to open a switch coupling both the parallel connected first battery and the parallel connected second battery to the load if the voltage is less than the threshold;
wherein the second voltage range has an upper limit less than the upper limit of the first voltage range but greater than the lower limit of the first voltage range, such that if the battery voltage of the first battery falls below the upper limit of the second voltage range, the second battery directly provides power to the first battery via the direct electrical connection between the first battery and the second battery to thereby prevent the first battery from falling below the lower limit of the first voltage range when both the first battery and the second battery are disconnected from the load.

2. The apparatus of claim 1 , wherein a lower limit of the second voltage range is smaller than the lower limit of the first voltage range.

3. The apparatus of claim 1 , wherein a battery capacity of the second battery is smaller than a battery capacity of the first battery.

4. The apparatus of claim 1 , wherein the first and second batteries are of an all-solid thin-film lithium ion type.

5. The apparatus of claim 1 , wherein the upper limit of the second voltage range is higher than a voltage beyond which the first battery is damaged.

6. The apparatus of claim 1 , wherein the first and second batteries have different electrochemical structures.

7. The apparatus of claim 6 , wherein a material used for positive electrodes of the first and second batteries is of LiCoO 2 type, wherein the positive electrode of the first battery is annealed at a first temperature, and wherein the positive electrode of the second battery is annealed at a second temperature, said first temperature being greater than the second temperature.

8. The apparatus of claim 1 , wherein positive electrode of the second battery is made of a material selected from the group consisting of: LiMn 2 O 4 , MnO 2 , Li 4 Mn 5 O 12 , LiV 3 O 8 , V 2 O 5 .

9. An electronic system, comprising:
a battery system including:
a first battery delivering battery voltage in a first voltage range; and
a second battery, directly electrically connected in parallel with the first battery, and delivering battery voltage in a second voltage range; and

a control circuit controlling a switch to disconnect both the first battery and the second battery of the battery system from a load to be powered when a voltage across the first and second batteries reaches a threshold;
wherein an upper limit of the second voltage range is between a high limit and a low limit of the first voltage range, such that if the battery voltage of the first battery falls below the upper limit of the second voltage range, the second battery directly provides power to the first battery via the direct electrical connection between the first battery and the second battery to thereby prevent the first battery from falling below the low limit of the first voltage range when the first battery and the second battery are disconnected from the load.

10. The system of claim 9 , wherein the threshold is greater than the low limit of the first voltage range and smaller than the upper limit of the second voltage range.

11. The system of claim 9 , further comprising a battery recharge element configured to recharge said battery system.

12. The apparatus of claim 1 , wherein the direct electrical connection between the first battery and the second battery is a direct unbroken electrical connection.

13. The system of claim 9 , wherein the direct electrical connection between the first battery and the second battery is a direct unbroken electrical connection.

14. The apparatus of claim 1 , wherein the direct electrical connection between the first battery and the second battery is a direct unbroken electrical connection devoid of intervening components.

15. The system of claim 9 , wherein the direct electrical connection between the first battery and the second battery is a direct unbroken electrical connection devoid of intervening components.

Assignees

• St Microelectronics Tours Sas

Inventors

• Bouyssou Emilien
• Guy-Bouyssou Delphine
• Cantin Frederic

Classifications

• H02J7/63

  against overdischarge · CPC title

• H02J7/663

  using battery or load disconnect circuits (H02J9/002 takes precedence) · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M16/00 Primary

  Structural combinations of different types of electrochemical generators · CPC title

• H01M10/0562

  Solid materials · CPC title