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.

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 Timetable

Sept Oct Nov Dec Jan Feb Mar Apr

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.