Resister cart observation

[monepit]

I have read on here that the down side to a resister cart is that at slow speed the batteries are having full power drained out of them. The motor is running slow because the resisters are draining part of the power from the motor and getting rid of it as heat. As an electrician that makes sense. This weekend I was driving the cart and I noticed that the battery voltage meter go's down with each increase in speed so that theory doesn't fly. It that was true the meter should keep the same voltage at any speed when the pedal is pressed. Any thoughts?

[jdunmyer]

Monepit,
The resistor bank isn't 'draining power from the motor', it's restricting the power from getting to the motor in the first place. Think of it as 'kinking the hose' to lower the flow [of electrons]. The resistors lower the overall current in the system, which is why your battery meter shows a higher voltage (less load) at part 'throttle' as compared to 'wide open'.

A resistor speed control definitely does waste some of your battery power, turning it into heat. A controller literally 'chops' the battery voltage as it goes to the motor, basically turning the switch 'on' and 'off' very rapidly, with the 'on' cycles becoming longer and longer as you press the pedal down. The only waste is a low level of heat generated in the controller.

Both systems will give you equal battery life if you're mostly running wide-open, but the controller setup will do better if you spend a lot of time just idling along. Just how much better depends on the percentage of time at wide-open vs. idle.

[monepit]

Makes sense. I knew it waisted it as heat. I had read it used the same at all speeds. I can see where it will use more than a solid state controller at low speeds but not as much at full speeds. This setup has worked very well for me. Just thinking out loud, I wonder if I increased the wire size to 2 awg, what that would do. I've heard that on a non resister cart, putting in a 400 or 500 amp controller on Ito will really increase your torque. On this cart it just runs down a copper buss and through solenoids. I wonder if I replaced the first and high speed solenoid with a 400 amp and upgraded the wires if that wouldn't be doing the same thing as upgrading the controller on a newer cart. I will say, compared to my newer controller operated cart this one has a lot more torque. I have had it climbing a 45 degree grade hill and it just won't stop.

[jdunmyer]

Increasing your wire size will increase your torque, mostly noticable at wide-open, probably not much at take-off, unless you mash the pedal down. Higher-rated solenoids won't help performance much, if at all, but will last longer, especially under heavy use.

FWIW: my first cart was an old Legend, resistor speed control with a wiper mechanism to short out the coils in turn. Most all the wiring is #6 gauge. It worked very well for me for well over 10 years, it would climb 9' long planks into my p/u truck, loaded with me and a few hundred pounds of tools. While it slowed down on hills, it always made it to the top. It did bug me a bit to feel the warm air wafting from under the seat during an evening tour of the campground, just idling along. I'm expecting to love my newly built 1979 CC with Curtis controller.