Just finished my RC controlled lawn mower. Pics below. I used the Sabertooth 2 X 32 motor controller. I wanted to see if anyone has been able to get any wheelchair motor specs to help get the right controller so I don’t overload the Sabertooth. I’m using a Hoveround Teknique XHD wheelchair base for the mower. The motor number looks to be a Merit M9EA-5R (right motor) . It states that the motor is 24Vt DC 200 watt motor that figures to be 8.3 amps. Am I doing this right? When running the DEscribe software on the Sabertooth, it shows to be pulling 9 to 10 amps while free spinning (no load). How can I tell what the motors are pulling while driving the mower around? Thanks for your help and this is a blast!!
Tom
Murry Wiring.doc (205 KB)
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Hi,
Wow, your RC Controlled Lawn Mower looks great. Nice job there 
As for the motors, 200W is the power output which can be approximated using the formula P=IV with I being the no load current and V nominal voltage.
As you have calculated, an approximation for the no load current would be 8.3Amps (200W/24V).
However, a DC Brushed Motor’s real power output value is : Total Power Input - Power losses with total power input being equal to IV and power losses equal to power losses through the copper + power losses through the brush.
This would explain the 9 to 10Amps you got.
For example, let’s say that the real current consumed by the motor with no load is 9.5Amps. The total power input would be 228W, therefore the power losses would be 228W-200W = 28W.
To obtain the real current consumed by the motors while driving the mower, you can use a multimeter with a datalogging function (connected in series with one of the motors).
Regards,
Thanks for the reply. I was going to use a laptop running the DEScribe software recorder hooked up to the Sabertooth and just run alongside the mower as it travels! Ha, Ha! Just want to make sure that the Sabertooth 2X32 can handle these motors!
Thanks,
Tom
That should do it too 
Hey Im also building one from a Hoveround HD. Do you by chance have a wiring diagram for the motor wires? Hoveround will not release one and I cant find anything online that identifies each motor wire. If you have something please email it to me at
[email protected]. thank you.