Title : Intelligent battery charger

Supervisor : Maeve Duffy

Student : Noel Walsh

Introduction• The project was a proposal from the PEP program carried out at

Blue Tree.• The Proposal : Intelligent Back-up Battery charger attached to a Dry

trailer system.• The circuit is expected to :

– Integrate with the R:COM system– Provide an interface to the tractor’s power source (Battery) when the

unit is attached.• The charger circuitry must provide a degree of intelligence to

determine – Is power source attached from tractor unit– Type of battery chemistry in back-up battery– Charging algorithm required for back-up battery– Safe voltage, current and temperature levels.

Introduction

• Variation in chemistries is to allow a choice for their customers based on– Cost – Capacity

• Why Back-up battery is required.

Research

• Battery chemistries: (Initially)– 20Ah Sealed Lead Acid ( 6 cells -> 12v) Panasonic

– 2Ah Lithium Ion (3 cells -> 11.1v) Worley-Parsons

• Battery chemistries: (development)– Nickel Cadmium

• R:COM Power requirements:– Input voltage operates between 11v to 24v (buck converter at input)

– Normal mode -> 2W

– Sleep Mode

Research

• R:COM system is available in USA and Europe– USA tractor unit battery -> 12v

– Europe Tractor unit battery -> 24v

– Switch mode converter required.

• Charging Algorithms:– When to begin a charge cycle

– Monitor process, voltage, current and temperature.

– Finishing a charge cycle

• Hardware Components:– Operating Conditions

– Safety issues

Research

• Software Required– Eagle : Schematic and Layout.

– Pspice : test and simulation.

– Microcontroller development environment.

Project Timetable

Sept Oct Nov Dec Jan Feb Mar Apr

Research

Design Requirements

Simulate/ test

Schematic

Hardware Prototype

Project Timetable

Sept Oct Nov Dec Jan Feb Mar Apr

Firmware

Test Prototype

Production Board

Debug

Test with R:COM system

Project Outline• Research battery chemistries and charging algorithms

– Lead Acid– Lithium-Polymer– Nickel Cadmium

• Outline the requirements and functionality of system.– Power requirements of R:COM system and connections– Monitor Voltage, Current and Temperature– Interface with tractor power source– Monitor back-up battery charge.

• Decide and source hardware components.– Microcontroller– Operating conditions for each part

Project Outline• Analyse and simulate charging algorithms.

– Properties of battery chemistries– Determine when to charge back-up battery, monitor the process and

when to stop.– Simulate with Pspice

• Design Schematic using Eagle.

• Prototype the hardware.– Test design

• Write firmware for microcontroller.– C programming language– Control charging process and monitor V,I and temp.

Project Outline

• Test Prototype for each charging algorithm.• Create production board in eagle layout.• Debug production board.• Test with R:COM system.

Expected Outcomes

• Develop a good understanding of battery re-charging circuits.

• Experience with hardware and software– High level of control required from both elements

• Research and analyse information/data.

• Standard expected for a commercial design.