PIC Battery Charger

1
PIC Battery Charger Team SD May03-05
Abstract
Many of today's new electronic devices require
rechargeable batteries to function. To be
practical, a battery charger should support 120V
AC, 220V AC, 50-60 Hz or 12V DC car inputs and be
portable. Many companies have produced battery
chargers that do one or two settings, but very
few have all three voltages and current
frequencies. Therefore, the team decided to
research the current knowledge concerning
rechargeable batteries and design a battery
charger based on quality and usability principle.
Members
Clients
Design Objectives
Richard Musumhi (EE) Pascal Openshaw (CprE) Bo
Bo Oo (EE) Chris Privitere (CprE)
Prof. John Lamont (Advisor Client) Prof. Ralph
Patterson (Advisor Client

• Develop a battery charger that can
• Use U.S., European, and vehicle outlet types
• Charge batteries intelligently using profiles.

Functional Requirements
General Background

• Use 120V/60Hz, 220V/50Hz, or 12V DC outlets
• Detect the fill on batteries
• Vary the charging current based on battery
  details

Very few battery chargers are capable of using
electrical outlets from the U.S., Europe, and car
adapters interchangeably and detecting when to
stop charging a full battery.
Technical Problem

• Create a battery charger that can
• Use multiple kinds of electrical outlets
• Vary the charge based on battery fill

Design Constraints
Operating Environment
Size and weight of the charger must make it
easily portable
Meant for use inside a house or automobile.
Intended users and uses
Measurable Milestones
Designed for frequent travelers who constantly
need charged batteries for portable electronic
devices.

• Project Definition
• Technology Selection
• Design Document

• Implementation
• Demonstration
• Documentation

Limitations

• AA and AAA NiCad and NiMH batteries only
• No more than 4 batteries at a time

End-Product Description

• Capable of charging up to four AAA/AA size NiCad
  or NiMH batteries
• Using either a car adapter or wall outlet from
  U.S. or European countries
• Small and light enough to fit in a travel pouch

Cash Budget
Sample commercial battery charger
Personnel Effort Budget
Testing Approach

• Power testing - voltage test - current test
  - charging status test

• Usability testing - batteries should not burn
  out - charging time limit - overcharge and
  undercharge - discharging