ENERGY INSTITUTE Battery Research Group NiMH Battery Pack for HEV Cem Kaypmaz 2008 İstanbul

General: Cell & Battery Electrochemical Cell converts the chemical energy contained in its active materials directly into electric energy by means of an electrochemical oxidation-reduction (redox) reaction. Battery consists of one or more of these cells, connected in series / parallel or both, depending on the desired output voltage and capacity. CellModuleBattery

ECE 15 Vehicle requirements and driving properties are defined by simulations as ECE 15. The ECE cycle is an urban driving cycle, also known as UDC.

ECE 15 The cycle was applied to the cells (1.2 V, 9Ah), sub modules (9 Ah, 72 V) and battery modules (9 Ah, 288 V) in order to obtain electrical and thermal properties. Over all, 40 cycles of ECE 15 was the project goal.

Heat Generation Experimental observations show that during high rate current discharge process the battery release heat. Heat generation of the sub modules without of voltage control in discharge process trough ECE 15 driving cycle was obtained. The temperature was increased to °C in minutes between 5-10 ECE 15 driving cycles.

Heat Generation

With the voltage control the cells and the modules completed all standard ECE 15 driving cycles in limiting heat generation also temperature differences (29°C to 32°C) and 15-17°C for the modules (from 29°C to 45-47°C).

Battery Management System Electrical management system was designed by using technical properties of the batteries and electrochemical properties of the cells. NiMH charging procedure was constant low current. Electrical Management System gives signal in out of ranges (min., max.) for the sub-modules which are out of range. Voltage [V]CellModuleBattery Minimum Nominal Maximum

Battery Management System Main Features; State of charge determination, Temperature controlled self discharge count Current, voltage and temperature measurements Every battery module has 4 different voltage and one temperature measurement Gives error signal in out of range values Sends information to vehicle electronic control unit and command.

Battery Management System Thermal management system has smart temperature control card which operete independent. This card was designed and produced with 12 temperature sensors for temperature control of the module. The system has maximum temperature alarm in 31 °C and minimum alarm in 23 °C. If one of the sensors is collapsed continuous cooling mode start and run air cooling system as emergency mode.

Battery Management System

Battery Module, Battery Management System Electrical Thermal

Prototype - goal 3 modules, each: 288V 50A 9 Ah Air Cooled NiMH 75 kg 50x70x24 cm 84 Liters

Prototype - final 3 modules, each: 288V 50A 9 Ah Air Cooled NiMH 65 kg 37x70x24 cm 62 Liters

Laboratory Infrastructure The prototypes were combined together in MRC Energy Institute Battery Research Labs. The sub module tests were realised in 72V – 2000A Battery Test System.

Laboratory Infrastructure

Tests Voltage drop test

Tests Loading up to 50A

Tests Loading up to 35A

Acknowledgements

THANK YOU TUBITAK MRC ENERGY INSTITUE PK. 21, GEBZE,KOCAELİ