Browse Prior Art Database

Dual Battery Extended Life, Auto-Charge Power Supply

IP.com Disclosure Number: IPCOM000061333D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Balliet, L: AUTHOR [+2]

Abstract

This article describes a system arrangement that permits dual redundant battery operation, optimizes battery life, predicts need for replacement, and extends operating time when primary power is disconnected. Rechargable batteries are candidates for use in portable computers as well as systems that must meet high "availability" requirements. In general, however, the life of batteries including rechargeables, has been considerably less than other electronic components. In computers especially, it is desirable to maximize life, extend service when primary power is removed or interrupted and predict in advance when replacement is required. The system disclosed herein provides these features.

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Dual Battery Extended Life, Auto-Charge Power Supply

This article describes a system arrangement that permits dual redundant battery operation, optimizes battery life, predicts need for replacement, and extends operating time when primary power is disconnected. Rechargable batteries are candidates for use in portable computers as well as systems that must meet high "availability" requirements. In general, however, the life of batteries including rechargeables, has been considerably less than other electronic components. In computers especially, it is desirable to maximize life, extend service when primary power is removed or interrupted and predict in advance when replacement is required. The system disclosed herein provides these features. Referring to the drawing, initially batteries A and B are fully charged, with battery B as backup and battery A as on-line supplying current to the load 1. In this configuration the status of the switches is as follows: Switch A = ON Switch B = OFF Switch C = OFF Switch D = OFF An end-of-life prediction microprocessor 2 continuously monitors on-line battery A and sends a "figure of merit" to the system microcomputer 3. As the end of the discharge point for the on-line battery is approached, the prediction microprocessor 2 detects same and sends a toggle signal 4 to the control logic 5 to switch to the backup battery B. The configuration of the switches is then as follows: Switch A = OFF Switch B = ON Switch C = OFF Switch D = OFF The prediction microprocessor 2 also notifies the microcomputer 3 that battery B is on-line and that the new backup battery needs charging. In order to ensure a longer battery life, it is desirable to fully discharge before recharge. The prediction microprocessor sends a discharge signal 6 to the control logic causing the backup battery to complete its discharge through the test load 7. In this case the state of switch D changes from OFF to
A. Discharge...