Battery Temperature Charge Voltage per cell Charge Voltage for a 12 Volt battery Gassing Voltage per cell Gassing Voltage for a 12V battery -20 °C * 2.67 to 2.76 16.02 to 16.56 2.97 17.82 -10 °C * 2.61 to 2.70 15.66 to 16.2 2.65 15.9 0 ° C * 2.55 to 2.65 15.3 to 15.9 2.54 15.24 10 °C 2.49 to 2.59 14.94 to 15.54 2.47 14.82 Battery Temperature Charge Voltage per cell Charge Voltage for a 12 Volt battery Gassing Voltage per cell Gassing Voltage for a 12V battery 20 °C 2.43 to 2.53 14.58 to 15.18 2.415 14.49 25 °C 2.40 to 2.50 14.40 to 15.00 2.39 14.34 30 °C 2.37 to 2.47 14.22 to 14.82 2.365 14.19 40 °C 2.31 to 2.41 13.86 to 14.46 2.33 13.98 50 °C 2.25 to 2.35 13.5 to 14.10 2.30 13.8 Figure 2.1 9 - Cyclic use charging (permission pending) Battery Temperature Charge Voltage per cell Charge Voltage for 12V Battery Gassing voltage -30 °C * 2.7 16.2 -20 °C * 2.34 to 2.38 14.04 to 14.28 2.97 -10 °C * 2.32 to 2.37 13.92 to 14.22 2.65 0 °C 2.30 to 2.35 13.8 to 14.1 2.54 10 °C 2.28 to 2.33 13.68 to 13.98 2.47 20 °C 2.26 to 2.31 13.56 to 13.86 2.415
Operating Temperature: -25C to 75C, 95C shutdown Adjustable via Controller Pro software: Throttle acceleration / deceleration rate and map profile Armature current limit Brake current limit Under / Over-voltage shutdown Half Speed Reverse High Pedal Disable Plug Brake [12] Using the programmable aspects of the AXE 4834 the following characteristics can be controlled. Acceleration/deceleration rate Armature current limit Brake current limit Under/over voltage shutdown Half speed reverse High disable Plug brake [12] The most efficient operation condition of the golf cart will be determined in the testing procedure for this project. [12] 2.1.5.3 PWM regen controller The final controller considered for this project was a programmable PWM controller with regenerative breaking capabilities. Regenerative breaking is an energy recovery method that charges the batteries as the golf cart stops. This is done by using the electric motor as an electric generator. Electric motors and generators are essentially the same machine. What separates them is the manner in which they are used. When a sufficient voltage and current are supplied to a generator or motor the armature will attempt to spin at a certain speed of rotation. If the rotational speed is decreased then the machine will act like a motor and apply force to the armature to try and maintain the speed of rotation. If the rotational speed of the machine is increased the armature will act like a generator which induces a back voltage and current that charges the batteries. Upon breaking the PWM regen controller will reduce the voltage supplied to the motor. This will in turn reduce the speed at which the armature will try to spin. The momentum of the golf car will then be increasing the speed that the armature is spinning. This will cause the back current and voltage produced to charge the batteries, while the back force produced will slow the golf cart. At slower speeds the stopping power as well as the energy return of regenerative breaking is greatly reduced. For this reason dynamic breaking using friction pads is still used to bring the golf cart to a full stop. The specific PWM regen controller used in the comparison of motor controllers is the TPM400. Refer to figure 2.1 20 for the TPM400. This programmable speed