Method for the automatic determination of battery chemistry in portable electronic devices

• US 6,215,275 B1
• Filed: 10/29/1999
• Issued: 04/10/2001
• Est. Priority Date: 10/29/1999
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Bean, Heather N.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/430,334
• Time in Patent Office: 529 Days
• Field of Search: 320/106, 320/162, 320/134, 320/136, 320/107, 324/429, 324/433, 340/636
• US Class Current: 320/106
• CPC Class Codes: G01R 31/378 specially adapted for the type of battery or accumulator

Abstract

A method that distinguishes different battery chemistries in portable electronic devices using a simple electrical test. The present method facilitates accurate fuel gauging as well as providing a safe in-device recharging scenario, eliminating the possibility that an end-user might attempt recharging a non-rechargeable battery. A simple circuit is provided in the electronic device that, in conjunction with a microcontroller, measures several distinct voltages across a newly inserted battery. A lookup table is then utilized to determine the probable battery chemistry.

Claims

1. A method for distinguishing different battery chemistries in a portable electronic device, the device having a battery compartment, the method comprising the steps of:

(1) determining whether the battery compartment has been opened;

(2) connecting the battery across a first resistor and measuring a first voltage drop;

(3) connecting the battery across a second resistor and measuring a second voltage drop; and

(4) dividing the first voltage drop the second voltage drop to obtain a resultant;

(5) using the resultant in connection with a lookup table to determine the battery chemistry.

2. The method of claim 1 further comprising the step of:

(6) if the battery chemistry determined in step (5) is indicative of a non-rechargeable battery chemistry, disabling any on-board battery charging circuits.

3. The method of claim 2 further comprising the step of:

(7) if the battery chemistry determined in step (5) is indicative of a rechargeable battery chemistry, providing a fuel gauge indicative of the charge remaining in the battery.