I still have the engine. I figure it will be useful to somebody else. I think horsepower should be fine. This is a 13” diameter forklift motor. It’s a beast.

That's what I'm thinking. Probably a 48V pack, as that's good for affordable and easily available parts. I'll probably re-use the physical throttle lever on the tractor and have some gearing connect it to the potentiometer. Have the full range of the physical throttle match up with however much of the range on the potentiometer I want to use.

@@BenjaminNelsonX Nice. Looking forward to seeing how this turns out.

That's exactly what a DC PWM motor controller does. It takes a battery pack voltage of, for example, 48V and outputs the equivalent of a variable voltage by simply turning the circuit on and off many times per second. If the duty cycle was set to 50%, the motor would spin as though it were running on 24V - half the speed.

​@@BenjaminNelsonX Just remember when you lower the voltage, you also lower the power of the motor. Also if you half the voltage you only get quarter of the original power so keep that in mind! I'm waiting for next update!

Additional gearing really starts adding a lot of mechanical complexities into a project like this. A PWM speed controller allows for maximum torque, while varying the speed.

Yes, it actually IS possible to do that. I have a friend who did that to a motor, but he is a skilled machinist and experienced in all sorts of fabrication. A motor described like that is known as a Permanent Magnet DC Motor. They are quite common for many applications. They tend to be more efficient (since the electric current is creating one magnetic field instead of two) but not provide as much torque. Still, magnets have improved over the years and come down is cost, and PM motors can be very powerful. For example, Tesla used induction motors on the Model S, but switched to PM motors for the Model 3.

@@BenjaminNelsonX Thank you for the quick and useful response, and I wish you success in all your work and lasting success.

The short answer is yes. The APU (Auxiliary Power Unit, or DC/DC converter) is rated at about 130 amps. At 12V, that's around 1500 watts. Keep in mind that you want to deduct some power for inefficiencies and the power the car itself needs for headlights, electronics, etc. The car should be able to run 1,000 watts continuously no problem. Running higher than that is fine too, but not at a high rate CONTINUOUSLY. If you draw more off the 12V system than the DC/DC converter can provide, the 12V battery (which is really acting as a buffer) will start to drop in voltage. I'm using a higher power inverter because I already had it and it allows for higher surge capability. Some electric devices don't draw high current while running, but will momentarily draw very high current just right as they start. The system can run my furnace and/or my refrigerator. Both really only take a few hundred watts each, but also run intermittently and have a higher starting current draw. On my setup, should the 12V battery voltage go too low, (because of a heavy continuous draw on the 12V system,) the 120V inverter automatically turns off. With that as a safety feature, there's really no way to overload the car.

Yes.

It was a fun project! My daughter had a blast!

I didn't use lithium batteries because I built this motorcycle in 2007. Lithium batteries would have cost about $10,000 at the time. I've used lithium on later projects, such as the Vectrix. kzbin.info/www/bejne/oJfLl2SEhtSVjbs

Yes, they are both 2012 model year cars.

No. That's not quite how LED bulbs work. Bulbs designed for 120V AC typically do have rectification and step-down circuitry inside them, but that doesn't mean they can run from any voltage. They are designed for that 120VAC input. You can't just put a 120V LED bulb on an 18V battery and have it work. Keep in mind that light bulbs are going to be designed to be as simple as COST EFFECTIVE as possible. A traditional 120V incandescent bulb CAN run on 18V, but it will only produce a dull glow. Here's an example: kzbin.infoRwQGGQx0_gc

Link to the Ryobi light bulb adapter is in the description, and here it is again: 300mpg.org/ryobi-18v-light-bulb-adapter/

A 4Ah battery ran the bulb for more than 8 hrs continuously. No difference in the amount of heat at the base of the bulb whether on 12v or 18v. Maybe I’ll hook the bulb up to the power supply and just keep it running continuously at 18 or 20v.