Hello community,
I my nominal oparating voltage of the battery I use will be 48 to 62.4 Volts. But the open circuit voltage of my battery will be 67.2Volts. The maximum back emf voltage of my rotor will be 48Volts.
RGBL 1860 according to the datasheet page 11 is able to deal with 63Volts.
My quesstion is which one of the two choices should I choose for my application?
Thank you
Hi @Tasos and welcome to the forum!
In order to choose a motor controller, you will need to provide the nominal voltage and continuous current of your motor. I recommend reading the following guide: https://community.robotshop.com/tutorials/show/how-to-make-a-robot-lesson-5-choosing-a-motor-controller
- The first consideration is the motor’s nominal voltage . DC motor controllers tend to offer a voltage range. For example, if your motor operates at 3V nominal, you should not select a motor controller that can only control a motor between 6V and 9V. This will help you cross off some motor controllers from the list.
- Once you have found a range of controllers that can power the motor with the appropriate voltage, the next consideration is the continuous current the controller will need to supply.You need to find a motor controller that will provide current equal to or above the motor’s continuous current consumption under load. Should you choose a 5A motor controller for a 3A motor, the motors will only take as much current as they require. On the other hand, a 5A motors is likely to burn a 3A motor controller.Many motor manufacturers provide a DC motor’s stall current, which does not give you a clear idea of the motor controller you will need. If you cannot find the motor’s continuous operating current, a simple rule of thumb is to estimate the motor’s continuous current at about 20% to 25% of the stall current. All DC motor controllers provide a maximum current rating - be certain this rating is about double that of the motor’s continuous operating current. Note that when a motor needs to produce more torque (for example going up an incline), it requires more current. Choosing a motor controller with built-in over current and thermal protection is a very good choice.
I hope that information can help you out 
Hi @geraldinebc15,
Thank you very much for your reply and the information you gave to me. My question had to do mainly with the first part of your answer. So at nominal condition the battery’s voltage will be from 62,4 (full charged) to 48 (cut off).
According to battery’s nominal operation and the Amps I need from my inverter, I have to choose the RGBL1860 because it’s maximum voltage is 63V. But I was thinking that I might have problem with the the voltsge range because my open circuit voltage is 67.5V is greater than RGBL’s 1860 maximum voltage.
So according to yor answer I should choose the inverter according to the battery’s nominal voltage and not according to battery’s open circuit voltage
Thank you much!
