48-Volt Wiring for EV Conversion

Published: 20 October 2021| Version 1 | DOI: 10.17632/g863cgnhh5.1
Nick Murray


Using a Series-Wound DC Motor from a 48-Volt Forklift, The following components were used to get this running an an EV conversion: - Series-Wound 48-Volt DC Motor (KOMATSU) - 48-Volt Contactor/Relay (KOMATSU) - CURTIS 1205 1205M-5601 Motor Controller - CURTIS PB-6 0-5k Ohm Potentiometer - QTY: 4 12-Volt/120 amp-hour Deep Cycle Batteries - 70mm2 Cable - 500 Amp Fuses


Steps to reproduce

To reproduce this Setup: - Obtain a Series-Wound DC Motor (can be any voltage range, however the higher the voltage the faster this motor will spin). - Purchase a motor controller (preferably brand-name, such as CURTIS) that works within the voltage and current range of your DC motor. - Purchase deep cycle batteries for powering the motor. The quantity of deep cycle batteries will be governed by the maximum voltage input specified on the DC Motor, however multiple deep cycle batteries can be placed in parallel to ensure voltage doesn't increase but the single-charge lifecycle of the battery array will. - Purchase a Contactor/Relay that can cope with high voltage and high current, preferably one that can be triggered by a 12-Volt input so as to utilise the stock ignition switch of a traditional vehicle. - Purchase cable that will be able to cope with high voltage and high current with minimal voltage drop. Typically any cable around the 70mm2 size is preferred. - Purchase fuses that will cope with the highest current output of your motor controller, say for example the CURTIS 1205 1205M-5601 Motor Controller has an output current MAXIMUM of 500A, thus 500 Amp fuses should be utilised to minimise risk of overloading the controller. Once all the above parts have been acquired, a bench test should be done to ensure all components work prior to being fitted and wired into the vehicle.


Waikato Institute of Technology - Rotokauri Campus


Engineering, Electrical Engineering, Mechanical Engineering, Automotive Design, Automotive Electronics