E-Moto Generator & Power Station Charging Guide

What Size Generator Do I Need to Charge My E-Moto?

Charging your electric dirt bike or e-moto from a generator or portable power station is easier than it might sound. The most important number to look at is the power draw of your bike's charger, not the peak power of the bike's motor.

A 20kW e-moto does not require a 20,000W generator to charge it. Your generator only needs to supply enough power for the charger and anything else you want to run at the same time.

Quick Rule: Check Your Charger

Look at the specifications on your e-moto charger.

• If the charger lists its AC input wattage, use that number.
• If you only know the approximate charger output voltage and amperage, you can estimate:
  Volts × Amps = Watts

For example:
84V × 10A = approximately 840W

Because of charging and conversion losses, actual AC power draw can be somewhat higher than this estimate. When possible, use the charger's listed AC input rating for the most accurate generator sizing.

We also recommend leaving additional capacity instead of continuously operating a generator at its maximum output.

For an e-moto charger drawing around 840W, a generator with approximately 1,200W or more of continuous output would provide useful additional headroom.

Don't Size Your Generator Based on Your Bike's Motor

This is one of the most important things to understand.

If your e-moto has a:

• 8kW motor
• 12kW motor
• 20kW motor
• 25kW motor

that does NOT mean you need an 8,000W, 12,000W, 20,000W, or 25,000W generator.

The motor's power rating tells you how much power the bike can use while riding.

The charger determines how much power is required from the generator while charging.

Want to Charge Your E-Moto and Run Other Equipment?

If you're heading to the track, camping, traveling, or preparing for an emergency, you may want your generator to do more than charge your bike.

Simply add together the approximate wattage of everything you expect to operate at the same time.

Example Track or Camping Setup

• E-Moto Charger: 900W
• Portable Fridge: 100W
• Lights: 100W
• Laptop & Phones: 150W
• Estimated Simultaneous Load: 1,250W

Instead of choosing a 1,250W generator and running it at or near maximum output, we recommend leaving some additional capacity.

A generator with approximately 1,800–2,000W of continuous output would provide much more comfortable headroom for this example setup.

Want to Charge Multiple E-Motos?

You can do that too, as long as your generator has enough continuous output.

For example:

• E-Moto Charger #1: 900W
• E-Moto Charger #2: 900W
• Other Equipment: 300W
• Total Load: 2,100W

Add approximately 20–30% additional capacity and you're looking at roughly:

2,500–2,750W+ continuous generator output

If you don't need to charge both bikes simultaneously, you can also charge one bike at a time and use a smaller generator.

Battery Size vs. Generator Size

Battery capacity and generator output are two different measurements.

Your e-moto's battery capacity tells you approximately how much energy the battery can store.

Your charger tells you approximately how quickly that energy needs to be supplied.

Watts (W) = Power

Watts tell you how much power your equipment needs at a particular moment.

Watt-Hours (Wh) = Energy

Watt-hours tell you how much energy a battery can store.

For example, a 4,000Wh (4kWh) e-moto battery does NOT require a 4,000W generator.

If the bike uses approximately a 1,000W charger, the generator only needs to comfortably support that charger's power requirements.

A 4,000Wh battery being charged at approximately 1,000W could theoretically require around four hours of charging from empty, but real-world charging time will generally be longer due to charging losses, battery management, charge tapering, and other factors.

What About Portable Battery Power Stations?

You can also charge many e-motos using a sufficiently powerful portable battery power station.

When choosing a power station, there are two important specifications to consider:

1. AC Output: The power station's inverter needs to provide enough continuous AC wattage to operate your e-moto charger.
2. Battery Capacity: The power station's Wh or kWh capacity determines approximately how much energy you have available to put back into your e-moto.

For example:

If your e-moto has a 4,000Wh battery and your portable power station stores 2,000Wh, you should NOT expect the power station to completely recharge the bike from empty.

Actual energy transferred to the bike will also be lower than the power station's advertised capacity because some energy is lost through the inverter, charger, wiring, battery management system, and charging process.

This is why both output wattage AND battery capacity matter when choosing a portable power station.

Can I Use a Generator to Charge My E-Moto During an Emergency?

Yes.

A properly sized generator can be an excellent backup charging solution during power outages, emergencies, extended trips, or anywhere normal AC power isn't available.

For modern e-motos and other sensitive electronics, we generally recommend a quality inverter generator with stable AC output.

Always confirm that the generator's voltage, frequency, continuous output, and outlet configuration are compatible with your charger.

Can I Charge a Tesla or Other Electric Vehicle?

Potentially, but EV charging is significantly more demanding than charging most e-motos.

Some properly configured generators may support emergency 120V Level 1 EV charging, while larger generators may be capable of supporting higher-output EV charging equipment.

However, EV charging equipment can have specific requirements involving:

• Voltage
• Continuous amperage
• Generator wattage
• Grounding/bonding configuration
• Outlet type
• EVSE compatibility

Having enough advertised watts does not automatically mean a generator will successfully charge every EV.

If charging a Tesla or another full-size EV is an important part of your intended use, choose a generator specifically suited for EV charging and verify compatibility with your vehicle and charging equipment.

Quick Generator Sizing Guide

These are general starting points. Always check the actual power requirements of your charger and equipment before selecting a generator.

Easy Generator Sizing Formula

If you're trying to figure out which generator is right for you, use this simple process:

1. STEP 1: Find the wattage or AC input requirements of your e-moto charger.
2. STEP 2: Add the wattage of anything else you want to operate at the same time.
3. STEP 3: Add approximately 20–30% additional capacity for comfortable operating headroom.
4. STEP 4: Compare your result against the generator's continuous/running wattage, not just its advertised peak or starting wattage.

Example

• E-Moto Charger: 1,000W
• Camping/Track Equipment: 300W
• Total Load: 1,000W + 300W = 1,300W

Add approximately 25% headroom:
1,300W × 1.25 = 1,625W

For this setup, we would start looking at generators capable of approximately 1,600W or more of continuous output.

Going larger gives you additional capacity for accessories and future equipment.

Generator Specs Worth Comparing

When shopping for a generator or power station for your e-moto, pay attention to:

Continuous / Running Watts

The amount of power the generator can continuously provide.

Peak / Starting Watts

Short-duration maximum output. Don't use this number as your primary sizing number for charging.

120V / 240V Output

Determines what types of equipment and chargers can be connected.

Inverter Generator

Generally preferred when powering chargers, electronics, and other sensitive equipment.

Fuel Type

Gasoline, propane, dual-fuel, or other options can affect convenience, runtime, and emergency preparedness.

Runtime

Important for charging large e-moto batteries, especially if a complete charge takes several hours.

Outlet Types

Make sure the generator has the appropriate outlets for your equipment.

Noise Level

Especially important for camping, events, pits, neighborhoods, and overnight use.

Portable Power Station Capacity (Wh/kWh)

For battery power stations, this determines approximately how much stored energy you have available.

Not Sure What Size You Need?

Send the REV Rides team:

1. Your bike make and model
2. A photo or specifications of your charger
3. How many bikes you want to charge
4. Anything else you want to power at the same time

We can help you determine approximately how much generator or power station capacity you should be looking for.