The goal at EV4U Custom Conversion is to provide you with the information you need to design and build an electric conversion that is safe, simple, reliable, and affordable. We also provide complete conversion service. Let us know how we can help you drive a custom electric conversion. Email info@EV4Unow.com
Basic Components used in an EV Conversion
- Battery Pack
- Battery Pack Charger
- Motor
- Controller
- DC/DC Converter
- Adapter/Coupler
- Additional items used include:
- Auxiliary Battery, Relays, Fuse Block, Safety Interlock, Inertia Switch, Meters, Gauges, Lights, Fuses, Pumps, Chill Plate, Radiators, Fans, Vacuum Pump, Pressure Switch, Vacuum Reservoir, Valves, Contactors, Heater Element, A/C Compressor, Switches, Terminal Strips, Terminal Posts, Wire, Connectors, Lugs, Heat Shrink, Cable, Shunt, Throttle, Motor Mounts, Charge Port, Power Steering Pump and so on.
Motors
- You want to match the motor to the load, not the peak performance figures. Failure of a motor is most common due to over-heating. A motor’s ability to dissipate heat is what will dictate its duty rating or ability to move a load over a period of time.
- Example of duty or load rating. A NetGain Motors HyPer 9 has a peak horsepower rating of 120 hp. The peak torque is 173 lb.-ft. however, the motor is not a good choice for vehicles with a gross weight of 3,500 or more as it will run hot.
- Series Wound DC/DC Motors like the NetGain Motors WarP 9 have some features that should be considered prior to purchasing an “inexpensive” DC motor.
- Series Wound DC Motors run hotter than an AC motors due to the commutator resistance and friction.
- Series Wound DC Motors do not offer regenerative braking.
- Series Wound DC Motors require maintenance that AC motors do not, such as brush inspection and/or replacement. Brush dust buildup which needs to be removed periodically.
- Series Wound DC Motors tend to be heavier than their AC counterpart.
- Series Wound DC Motors can use a wide range of controllers as long as the current and voltage ratings are compatible.
- Most DC controllers offer limited programming options.
- Series Wound DC Motors are not currently the best option for vehicle conversions.
- AC Motors are mated to an inverter.
- AC Motor inverters tend to have a wide range of programing options.
- AC Motors offer regenerative braking.
- Two common types of AC motors are; the AC Induction Motor and the Permanent Magnet Synchronous Reluctance Motor.
- An example of an AC Induction Motor is the HPEVS AC-50.
- The NetGain Motors HyPer 9 is an example of a Permanent Magnet Synchronous Reluctance motor.
- Things to consider when choosing a motor are; vehicle weight, battery pack voltage, physical dimensions of the motor, performance statics including continuous power rating.
- Other considerations might be; warranty, country of origin, service centers, dealer network.
- Some common motors and there specifications.
- HPEVS AC-50 – three-phase AC Induction Motor, 76 hp, 120 lb.-ft. of torque, typically mated to the Curtis 1238 Controller with a maximum input voltage of 130 volts and a maximum current of 650 amps. Weighs 115 lbs. and is rated for vehicles up to 3,500 pounds. Features internal fan cooling. Easy setup and programming. Includes the Curtis 840 Display. A computer is not required. Made in the USA.
- HPEVS AC-51 – three-phase AC Induction Motor, 88 hp, 108 lb.-ft. of torque, typically mated to the Curtis 1239 Controller with a maximum input voltage of 170 volts and a maximum current of 500 amps. Weighs 115 lbs. and is rated for vehicles up to 4,000 pounds. Features internal fan cooling. Easy setup and programming. Includes the Curtis 840 Display. Computer not required. Made in the USA.
- HPEVS AC-35×2 – three-phase AC Induction Motor, 165 hp, 189 lb.-ft. of torque, typically mated to two Curtis 1239 Controllers with a maximum input voltage of 170 volts and a maximum current of 1,000 amps. Weighs 150 lbs. and is rated for vehicles up to 3,500 pounds. Features internal fan cooling. Easy setup and programming. Includes the Curtis 840 Display. Computer not required. Made in the USA.
- NetGain HyPer 9 – Permanent Magnet Synchronous Reluctance AC Motor, 120 hp, 173 lb.-ft. of torque, mated to the AC-X1 Controller with a maximum input voltage of 130 volts and a maximum current of 750 amps. Weighs 120 lbs. and is rated for vehicles up to 3,500 pounds. A computer is required for setup and programming. SME Dash Display is sold separately. Made in the Italy by the SME Group.
- NetGain HyPer 9 HV – Permanent Magnet Synchronous Reluctance AC Motor, 120 hp, 165 lb.-ft. of torque, mated to the HyPer-Drive X144 Controller with a maximum input voltage of 180 volts and a maximum current of 500 amps. Weighs 130 lbs. and is rated for vehicles up to 3,500 pounds. A computer is required for setup and programming. SME Dash Display is sold separately. Made in the Italy by the SME Group.
- EV4U is a dealer for both HPEVS and NetGain Motors.




Batteries
- Lots of different battery chemistries are currently available.
- Common chemistries are:
- Lithium Cobalt Oxide (LCO) – Thermal Threshold 302 degrees Fahrenheit
- Lithium-manganese-cobalt-oxide (NMC) – Thermal Threshold 334 degrees Fahrenheit
- Lithium Iron Manganese Phosphate (LiFeMnPO4)
- Lithium Iron Phosphate (LiFePO4) – Thermal Threshold 512 degrees Fahrenheit
- LiFePO4 is the safest chemistry available.
- LiFePO4 has the highest number of life cycles.
- Cell voltage is dictated by the chemistry.
- You should know the three voltages; maximum charge-to voltage, minimum discharge voltage, and nominal voltage.
- Range is determined by the usable battery pack capacity divided by the consumption rate (watt-hours/mile).
- Everything you need to know about batteries is available at www.EVWorkshops.com

Adapter/Coupler


- The Adapter is what mates the electric motor to the transmission bell housing.
- The Coupler mates the motor output shaft to the flywheel clutch assembly.
- For more information about Adapter/Couplers, check out our YouTube channel.

How about direct drive (no transmission)?
- Typically if you want to go with a direct drive setup, then an OEM swap is the route to take.
- The motors listed above are not really compatible with a direct drive setup.
- Check out this video, for the reason we typically retain the transmission.
How about using components from a used or salvaged EV?
- You can get used or salvaged EVs for a reasonable price.
- Requires knowledge of how to safely handle high voltage.
- Typical EV conversions are under 200 volts.
- Factory EVs can be over 400 volts.
- Requires more skill sets to do a conversion this way.
- More general knowledge.
- More fabrication work.
- Check out our video on the topic.
Generic HPEVS AC-50 Schematic

Generic HPEVS AC-51 Schematic

Instrumentation

- Items typically monitored on a conversion.
- Monitor Battery Pack – Volts, Amps, SOC, Temperature
- Motor Motor and Controller – Volts, Amps, RPMs, Temperature
- Monitor 12-volt Battery and DC/DC Converter
Answers to frequently asked questions
- Question: Why don’t you sell components directly from your website?
- Answer: Many people do not have a good enough understanding of the big picture and may make poor choices when purchasing components. We are more concerned with your successful conversion than we are about quickly making money from someone ordering the wrong components for the job.
- Question: Can I convert my Suburban to electric?
- Answer: Any vehicle can be converted to electric, but not all are practical to convert. Weight affects both range and cost. The heavier the vehicle the greater the cost for any given range. Another consideration is the value proposition. Adding $60,000+ to a Suburban may not be the best value. But adding $26,000 to a classic Porsche is probably not going to be a bad decision.
- Question: How much does a conversion cost?
- Answer: One of the least expensive conversions is a classic VW Beetle. A complete conversion from EV4U runs $23,995. The price goes up from there to over six figures depending on the vehicle, range, performance, etc.
- How about if I convert it myself?
- Conversion component packages usually start off at around $16,000.
- Question: Why can’t I get the same range as a Tesla or other factory produced EV?
- Answer: With an EV conversion you have limitations based on the vehicle you choose. Examples are the drag coefficient. A classic VW Beetle has a drag coefficient of 0.48 and a Tesla Model S has a 0.24 (the lower the number the less the drag). So even if you put the Tesla Model S battery pack in the Beetle it would not have as much range. Another issue is the vehicle’s payload. Payload is the amount of weight the vehicle can safely carry. Payload is the difference between the vehicle’s GVWR and the curb weight (or converted weight). An example is the Mazda Miata and a classic VW Beetle. The payload for the Miata is 380 pounds. The Beetle has a 860 pound payload. Payload limitations restrict the size of battery pack that can be safely used.
- For additional FAQs check out our YouTube channel.
Basic Conversion Range Formula
- What you need to know to calculate the range of your conversion.
- Range is equal to the Usable battery capacity divided by the consumption rate.
- Gross Converted Weight (Curb weight of vehicle after conversion plus driver, passengers, and cargo).
- Usable battery pack capacity. Typically 80% of total pack capacity.
- To figure total pack capacity; multiply pack nominal voltage by the Ah rating.
- To figure the consumption rate; divide the Gross Converted Weight by 10. (This will give you the watt-hours per mile.)
- Divide the Usable Battery Pack Capacity by the Watt-hours per mile and you have the range.
DIY Cost Estimator
This tool will give you a good idea of what it will cost to convert a vehicle from internal combustion to electric if you do-it-yourself.
Designed for vehicles under four thousand pounds.
This Estimator takes into account all of the costs, not just the main components. Keep track of your costs and let us know just how close the tool calculates. You may be surprised.
DIY costs can vary based on whether of not you use new or used components. Your talents and skill sets. Where you are located.
You will need some basic information in order to use the Estimator.
The Gross Vehicle Weight Rating (GVWR) is the maximum weight of the vehicle as determined by the manufacturer.
The Curb Weight is the weight of the stock vehicle without any passengers and with all of the fluids topped off.
The Payload is the difference between the GVWR and the Curb Weight and the total weight of passengers and cargo the vehicle can carry. Once your vehicle is converted the total weight with passengers and cargo must not exceed the GVWR.
Click the Download button to download the Excel Spreadsheet.
On the spreadsheet, enter the GVWR and the Curb Weight.
Place a 1 in the box below the appropriate Weight Range.
Place a 1 in the box below the Payload. Either the Payload is less the 500 pounds or greater than 500 pounds.
If the vehicle has Power Brakes place a 1 in that line in the YES column.
Do the same for Power Steering and Air Conditioning.
Refer to the example below.

Cost per mile comparison between gas and electric
- Calculates the cost per mile to drive an internal combustion vehicle with an electric vehicle.
- Click the Download Button to download the Excel spreadsheet.
- Enter the cost per kWh where you charge your EV.
- Enter the number of miles you drive daily.
- Enter your vehicles fuel mileage (miles per gallon).
- Enter the cost per gallon for the fuel.
- The spreadsheet will display the following:
- Cost for gas per mile, per day, per month, per year, and the cost at 3, 5,7, and 10 years.
- Shows the cost of driving electric for the same distance/time.
- Shows the comparison between the cost of driving a gas car versus an EV.
- See the example below.

Vehicle Transport

Cost of a conversion

Some people comment that conversions are expensive. The bottom line is that it is not about the cost it, is about the car. If you want an inexpensive EV I would recommend a lease return. Probably the best value on a used vehicle. A conversion is similar to building a hot rod or restoring a classic vehicle, it’s about the ride, not the price.
