Power and torque upgrade guidance

[ChuckW]

Originally Posted by JohnnieB

R-1 (38 Second duration)
Max Speed = 19.4 MPH
Max Battery Amps = 286.3A
Start Battery Voltage = 37.4V
Min Battery Voltage = 30.7V
Voltage drop = 6.7V
Voltage drop per 100A = 2.34V
M- Temperature Rise = 1.8°C

R-2 (69 Second duration)
Max Speed = 21.8 MPH
Max Battery Amps = 273.7A
Start Battery Voltage = 38.0V
Min Battery Voltage = 29.4V
Voltage drop = 8.6V
Voltage drop per 100A = 3.14V
M- Temperature Rise = 1.1°C

100% throttle was reached during both runs.
No error flags appeared during either run.

Typical voltage drop per 100A for the batteries in and of themselves for a healthy 36V battery pack is 1V/100A and your pack is dropping two to three times that amount. High current cables and connection plus solenoid contacts are included in the voltage drop in your cart, but you have new 2Ga cables, new 400A solenoid and newly cleaned connections, so the V/100A calculations mostly reflect what the batteries are doing.

Thanks again Johnny. I will definitely be looking into batteries now.

[ChuckW]

One month update:

So I've been using my cart pretty regularly since adding all of the upgrades. I've carried three men and all of the gear we've needed for a full day of clay shooting on several occasions now, and performance has been surprisingly good, even with the stock motor and 36v power. Obviously speed hasn't been real high, but high enough for what we're doing.

The batteries seem to have rebounded a bit and are performing very well. I guess it helps when you get good cables on the buggy and change out all of the old corroded connectors so they get a good charge! At this point I plan to run the cart until the batteries need replacing and then go to 48v. I still haven't run the cart in real hilly terrain with a full load yet, so the jury is still out on the motor upgrade. As you can see by the pics, it's turned out to be a pretty good cart for the intended purpose!

[JohnnieB]

Looking good.

(The cart that is.)