ElectricScooterParts.com Support Center

Forum Topic Update: We now have several Rhoades car electric power modification kits available on this page: https://cart.electricscooterparts.com/store/Search.aspx?searchTerms=Rhoades+car+kit

We do not carry a 48 Volt 750 Watt motor like the MOT-481000PL, however, on flat ground, a 1000 Watt motor will not consume anywhere near 1000 Watts at slower speeds and we would only expect it to consume a few hundred Watts at speeds 10 MPH and under unless there was a strong headwind. It will consume 1000 Watts during fast acceleration but that can be kept under control by accelerating slowly to conserve battery power. 

Our phone reps know their stuff, however, they do not have as much experience as we do here in the technical support department so for the absolute best advice on getting the right parts we recommend using our online forum or support ticket systems.

Please let us know if you have any further questions and we will be glad to help. 

I believe that the MOT-481000PL is the best motor for your application due to its high power output. A 1000 Watt motor can power a vehicle on flat ground to around 25 MPH, however, having a lower top speed gearing is better if the vehicle will need to climb hills. 

For a cruising speed of 6-10 MPH a top speed gear ratio of 10 MPH could be used which would provide the fastest acceleration and best hill climbing performance, or a faster than 10 MPH top speed gear ratio could be used so the vehicle can travel faster when needed and still have decent hill climbing ability. For example, the top speed gear ratio could be for let's say 18 MPH, and then the vehicle can easily cruise at 6-10 MPH and also go 18 MPH when needed. I ran a top speed calculation for 18 MPH and got a result with an 18 tooth axle sprocket.

The right side of the bike with the motor spinning clockwise is correct for this motor. 

Please let us know if you have any questions.

Regarding the axle sprocket, there are two different options:

Option one is to have a non-freewheel axle sprocket that allows the motor to move the vehicle in both forward and reverse directions. This option does not allow for easy pedaling of the car though because the motor will always be geared to the axle which would make the car difficult to pedal when the motor is off. 

Option two is to have a freewheel axle sprocket that allows the motor to power the car in the forward direction only. This option allows the car to be pedaled and pushed forward without any drag or resistance from the motor when the motor is off. 

Please let us know which sprocket option you prefer and then we can put together a list of parts that are needed for the project. Once we have the parts list then we can make a kit out of them with a 10% kit discount. 

We can go ahead and make the kit so it is ready to order. We just need to sort out a few details first.

The smallest sprocket for #420 chain we can get is 27 teeth. This 27 tooth axle sprocket along with a 14 tooth motor sprocket installed on the MOT-481000PL motor works out to a top speed of 15.46 MPH. Is this top speed okay?

Here is a preliminary parts list for the kit:

1 qty. MOT-481000PL motor

1 qty. SPR-42014E2 14 tooth motor sprocket

1 qty. SPR-42027F5 27 tooth axle sprocket for 5-hole freewheel

1 qty. FWM-205 5-hole freewheel

1 qty. HDW-200 5-hole sprocket to freewheel mounting hardware

1 qty. FWM-ADAPTER3 freewheel to 3/4" axle adapter

1 qty. #420 Chain (how many links?)

1 qty. SPD-481000D 48V 1000W heavy-duty controller

1 qty. RLY-48150 48V 150A heavy-duty power contactor

1 qty. CNX-830 battery pack/motor wires junction box

1 qty. THR-115K twist throttle with battery meter and key switch

1 qty. Battery Pack Wiring Harness (we can include this part if you want?)

Please let us know if the gear ratio with 27 tooth axle sprocket is okay, how many links of chain you would like, and if you want a battery pack wiring harness included with the kit, and then we can go ahead and make a page for the kit and reply with the link. 

Also, if you need batteries and a battery charger with the kit then please let us know.

Please let us know if you have any questions.

The original calculation with 18 tooth axle sprocket was for a #410 sprocket which is only 1/8" wide. We can not get an 18 tooth axle sprocket for #420 chain (1/4" wide) so that is why I switched over to the 27 tooth axle sprocket for #420 chain which is the smallest size available. The 14 tooth motor sprocket and 27 tooth axle sprocket will provide more torque than our original calculation with the 11 and 18 tooth sprockets. 

Everything on the list excluding the chain and battery pack wiring harness adds up to $451.50 and with the 10% kit discount, the discount price is $406.35.

Please let us know if you have any questions. 

We just got the kit finished. It is our item # KIT-481000G-25. Here is the link to it:
https://cart.electricscooterparts.com/48-volt-1000-watt-rhoades-car-electric-motor-power-kit

Please let us know if there is anything you would like changed on the kit, or if you have any questions.

It sounds like the battery pack is dropping too much Voltage under load. The five lights on the throttle are a Voltage level indicator and the if the red light is the only light on that indicates that the battery pack Voltage level is at or below zero percent (too low to operate the motor), and if the red light turns off and no lights are on that indicates the battery pack Voltage level is at far below zero percent.

The throttle battery level indicator lights function as follows:

Red = ≤0%

Yellow = 0%-25%

1st Green = 25%-50%

2nd Green = 50%-75%

3rd Green = 75%-100%

On the THR-115K throttle's battery level indicator, 0% is around 42 Volts and 100% is around 55 Volts.

Using a multimeter set to DC Volts we would verify the battery pack Voltage with the power switch on and throttle in the full throttle position to verify the condition of the battery pack. If the multimeter's battery pack Voltage readings correspond with the throttle indicator's Voltage readings then that will confirm a problem with the battery pack. 

Please let us know how it goes.