I would like to know the type of battery that I can use to power a banebots rs-550 motor and motor controller for 30mins to an hour
I am a little confused about the battery discharge rate. Do I need one battery per motor? And of so does this mean I csnt use a dual motor driver to run two of them? And what battery would work? Could someone provide a sample link to the type of battery needed ?
Thank you, I’m sure this had been asked a million times but I can’t find a direct straight forward answer
The Banebots RS-550 motor consumes 85A under stall, so under normal operating conditions (loaded), it will easily consume ~20-25A. The battery you select shoudl therefore be able to supply at least 25A of current continuously.
If you are consider an 11.1V LiPo battery, the discharge rate relates to the capacity ‘C’. For example if an 11.1V, 2400mAh LiPo battery is rated for 5C, it can discharge at 5x 2400mA = 5 x 2.4A = 12A. This would not be sufficient for this motor.
If you find a different battery, for example an 11.1V, 5200mAh LiPo rated at 20C, it can discharge at 20 x 5200ma - 20 x 5.2A = 104A which is more than enough.
If your robot uses two motors, they would consume a maximum combined current of ~40 - 50A. You should certainly still use one battery, but be certain it can discharge at 50A or more (preferably much more).
The Lynmotion 11.1V 2800mAh 30C LiPo battery (RB-Kow-06) can discharge at 30 x 2.8A = 84A, which is above the minimum 40-50A you might need.
Lead acid batteries can normally discharge at high current, but NiMh normally discharge at 1-2C, so despite having a high capacity, they cannot provide high current.
As far as the specs, it’s really tight at 25A. If you plan to operate the motor below the rated load it may work, but to be safe, we would suggest choosing a controller which can provide more current.
How do you work out the size of the motor driver for a given motor. 25% of the stall current is what i did which gave me 21amp for an 85amp stall current. I know thats just a rough guide. Are you just adding a bit on top of that? Or Is there a more accurate way to tell from the specs?
So how big should i go to be truely safe? I would like to able to run the motor at its max… Will 30a do or should i go as high as 40a
i have read that page, i found it really helpful. It was there were i read about calculating how many amps the motor will use. I was just a little confused when you said the motor would easily consume 20-25 amps. The information on the page said its 20-25% of the stall current if you cant find the continuous current rating listed for the motor.
my maths gave me a value of 17 to 21.25
the bit i didnt take in on the first time was the part saying the motor controllers maximum should be double the motors continuous current.
so if 21.25amps for the motor would a 50a ish controller leave enough.
or if its 25amps then a 60a ish controller.
if all this is only a rough estimation then i would prob choose a 60a dual controller. Does that sound better?
Thanks for the support, i’m trying to figure it out i dont want to blow stuff up and theres a good chance i will…
Once again, a 25A controller may work in most situations if the maximum continuous current you find under load s around 21A. If you take one which has built-in safety (like over-current and thermal protection), the motor controller will simply shut down and give an error instead of burning. If you don’t have any issue with this, then choosing a 25A controller will be fine.
A higher power controller however will continue to provide power if you go beyond the 21A, so the chance of maxing out is reduced and the robot will continue to operate even under “stress”.
Yup. That would be very safe.
Even better, perhaps even a bit overkill.
It would obviously cost more, but a lot less to worry about.
