Battery Performance Under high Temperature Exposure

Patent metadata

Field	Value
Publication number	US-2016097820-A1
Application number	US-201414504683-A
Country	US
Kind code	A1
Filing date	Oct 2, 2014
Priority date	Oct 2, 2014
Publication date	Apr 7, 2016
Grant date	—

Abstract

A battery system for a portable information handling system may modify charging parameters based on temperature exposure of a battery. When the battery is charged and exposed to a high temperature, the battery may be discharged to a lower voltage. After a cumulative period of exposure to a high temperature, a top-of-charge (TOC) voltage may be permanently reduced for the battery. Prior to charging at a high temperature, the TOC voltage may be reduced for a next charge cycle. Reducing the TOC voltage may minimize adverse effects for battery performance.

First claim

What is claimed is:

1 . A method for charging a battery, comprising:
when the battery is charged and the battery temperature is greater than a first temperature threshold, discharging the battery to a first voltage threshold, wherein the first voltage threshold is less than a top-of-charge voltage of the battery; and when the battery temperature is greater than a second temperature threshold for a first duration, permanently reducing the top-of-charge voltage to a second voltage threshold, wherein the second voltage threshold is less than the maximum charge voltage of the battery.

2 . The method of claim 1 , wherein the first temperature threshold and the second temperature threshold are determined based at least in part on a battery chemistry of the battery.

3 . The method of claim 1 , wherein the first voltage threshold and the second voltage threshold are determined based at least in part on a battery chemistry and a service age of the battery.

4 . The method of claim 1 , wherein discharging the battery to the first voltage threshold includes switching a dummy load to output terminals of the battery.

5 . The method of claim 1 , wherein discharging the battery to the first voltage threshold includes switching off an external power source to the battery.

6 . The method of claim 1 , wherein a discharged battery is at less than 5% of a state of charge corresponding to the top-of-charge voltage, and wherein a charged battery is at greater than 25% of the state of charge corresponding to the top-of-charge voltage.

7 . The method of claim 1 , wherein a battery chemistry of the battery is a lithium-ion chemistry, and wherein the first temperature threshold and the second temperature threshold are 60° C., and the first duration is a cumulative duration of 96 hours.

8 . A battery system comprising:
a battery; and a battery management unit comprising a processor and memory media, the memory media storing instructions executable by the processor to:
when the battery is charged and the battery temperature is greater than a first temperature threshold, discharging the battery to a first voltage threshold, wherein the first voltage threshold is less than a top-of-charge voltage of the battery; and
when the battery temperature is greater than a second temperature threshold for a first duration, permanently reducing the top-of-charge voltage to a second voltage threshold, wherein the second voltage threshold is less than the maximum charge voltage of the battery.

9 . The battery system of claim 8 , wherein the first temperature threshold and the second temperature threshold are determined based at least in part on a battery chemistry of the battery.

10 . The battery system of claim 8 , wherein the first voltage threshold and the second voltage threshold are determined based at least in part on a battery chemistry and a service age of the battery.

11 . The battery system of claim 8 , wherein the instructions to discharge the battery to the first voltage threshold include instructions to switch a dummy load to output terminals of the battery.

12 . The battery system of claim 8 , wherein the instructions to discharge the battery to the first voltage threshold include instructions to switch off an external power source to the battery.

13 . The battery system of claim 8 , wherein a discharged battery is at less than 5% of a state of charge corresponding to the top-of-charge voltage, and wherein a charged battery is at greater than 25% of the state of charge corresponding to the top-of-charge voltage.

14 . The battery system of claim 8 , wherein a battery chemistry of the battery is a lithium-ion chemistry, and wherein the first temperature threshold and the second temperature threshold are 60° C., and the first duration is a cumulative duration of 96 hours.

15 . An information handling system, comprising:
a battery system, the battery system comprising:
a battery; and
a battery management unit comprising a processor and memory media, the memory media storing instructions executable by the processor to:
when the battery is charged and the battery temperature is greater than a first temperature threshold, discharging the battery to a first voltage threshold, wherein the first voltage threshold is less than a top-of-charge voltage of the battery; and
when the battery temperature is greater than a second temperature threshold for a first duration, permanently reducing the top-of-charge voltage to a second voltage threshold, wherein the second voltage threshold is less than the maximum charge voltage of the battery.

16 . The information handling system of claim 15 , wherein the first temperature threshold and the second temperature threshold are determined based at least in part on a battery chemistry of the battery.

17 . The information handling system of claim 15 , wherein the first voltage threshold and the second voltage threshold are determined based at least in part on a battery chemistry and a service age of the battery.

18 . The information handling system of claim 15 , wherein the instructions to discharge the battery to the first voltage threshold include instructions to switch a dummy load to output terminals of the battery.

19 . The information handling system of claim 15 , wherein the instructions to discharge the battery to the first voltage threshold include instructions to switch off an external power source to the battery.

20 . The information handling system of claim 15 , wherein a discharged battery is at less than 5% of a state of charge corresponding to the top-of-charge voltage, wherein a charged battery is at greater than 25% of the state of charge corresponding to the top-of-charge voltage, wherein a battery chemistry of the battery is a lithium-ion chemistry, and wherein the first temperature threshold and the third temperature threshold are 60° C., and the first duration is a cumulative duration of 96 hours.

Assignees

• Dell Products Lp

Inventors

• Thompson Richard C
• Chang Wen-Yung

Classifications

• H02J7/977

  of the battery · CPC title

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/445

  in response to measured battery parameters, e.g. voltage, current or temperature profile · CPC title

• G01R31/374 Primary

  with means for correcting the measurement for temperature or ageing · CPC title

• G01R31/3655

  Physics · mapped topic