Goals To Determine Before Your EV Conversion
Some goals need to be defined before starting your diy electric car or ev car conversion shop. Each goal in the list is directly related to the goal set before. Goal number 1 is the most important goal for the overall electric conversion and so on to number 11. Even if you are planning to take your vehicle to an ev conversion shop, you will need to describe your end goals. A project like this, or any other major project, needs to be well thought out in order to avoid surprises in the final stages.
At first glance, these 11 items may seem obvious based on your initial instinct of what an electric vehicle or ev conversion typically looks like. I urge you to continue through the list and evaluate each item to make sure that they had been planned accordingly to your overall vehicle conversion goal.
1. Vehicle Type
What type of vehicle do you plan to convert?
Is it a car, truck, or SUV? What is the size of the vehicle? This might sound like the most obvious question to those who already have a vehicle selected. At this point, you usually have some picture of the vehicle type and size you want to use. To state that you want to use a truck does not provide enough information. For example, a light pickup like a Ford Ranger, or 1/2 ton pickup like an F-150.
2. Overall Budget
What is your overall budget for this project?
The biggest limiting factor to your project goal will be money. This will be the driving factor on the following items like battery type/pack, performance and range requirements. These three items are key areas that will change not only the cost of the vehicle conversion but also the driving experience.
If you do not have the budget that you require to hit some of your must have requirements for your EV conversion, then there is always the option of doing the conversion yourself. This, however, will take more time than using a conversion shop that does it all the time.
3. DIY or Conversion Shop
Who will be doing the work, yourself or a conversion shop?
It may not have crossed your mind that a conversion shop can do all of the required work. While some insist on doing the work themselves. The main objective is to know your options. It comes down to a couple of factors: are you comfortable with typical automotive repair, and do you have the time to complete the entire process. If you answered yes to both of these questions then a, DIY, do it yourself option might be what you are looking for.
Do not let me sway you into converting a DIY electric car if you want to keep the free time that you have. Time is one of the only things we have control of in our lives, but keep in mind that using a professional conversion shop will cost you more money and could drastically reduce the completion time. Since they are using the same components that you would have purchased and installed the main cost is labour and the facility. A rough estimate of a professional conversion cost would be between $6,000 to $8,000 additionally to the components cost which means that the budget would need to be adjusted.
4. Range Requirements
What is the average driving distance your EV will see?
Typically an electric vehicle would be used as a daily drive vehicle, and most daily commuters already know how long a drive they have to work. Keep in mind that there are days that take longer, so use your longest commute that you have had, and factor in a round trip.
If you are not sure how much range to estimate, under the assumption that it will be a daily driver, you can estimate the average commute time in the U.S.A. which is just over 25 minutes. This will be a mix of urban, suburban and highway traffic. You can identify the distance that would be required at highway speeds for each trip, to and from work. I would recommend allowing more range than your typical round trip drive. Find your minimum acceptable range so that you have an idea of where to start.
Having a higher range is a safer route to take, for peace of mind, and will effect the battery pack size. A larger battery pack will increase cost and weight, depending on the vehicle type that you have selected, the allowable weight for the axles will be a limiting factor.
5. Performance Requirements
What are your performance expectations?
The first instinct for most people is to try and find an electric motor that will directly replace the horsepower and torque that was originally installed. There is a constant balancing act between cost, range and performance. If you want high range and the same or higher performance than the original engine, then the cost will increase.
Most electric vehicle conversions use slightly less powerful electric motors than a gasoline engine, the reason is to allow for more batteries to be used, which increases the range.
6. Battery Type / Pack
Lithium Ion or Deep Cycle Lead Acid Batteries?
The selection of using lithium ion batteries versus a deep cycle lead acid battery pack is a matter of cost and weight. Lithium-ion batteries have a higher density over equivalent deep cycle lead acid batteries. As a result, the lithium-ion battery will weigh less, and will maintain a higher power to weight ratio. The downside is that the lithium batteries will cost much more than deep cycle lead acid batteries.
No matter which battery type your selection, the appropriate battery management system, BMS, will need to included to your vehicle conversion. This is a required component with any battery type as they provide protection from overcharging. This enables you to charge overnight either with a standard 120VAC supply or a level 2 charging which is 240VAC.
7. Vehicle Age / Condition
How old is your vehicle and in what condition is the vehicle?
Something to consider is the mileage that is on the chassis, and it doesn’t really matter how old the vehicle is, to a degree. One of the main issues is the wear of wheel bearings, suspension, body on uni-body cars, and frame on trucks. Another issue is rust, or more importantly the depth of the corrosion. It is normal to see shallow or surface rust on the undercarriage of a vehicle over 5 years old. Areas to check are rocker panels and wheel wells.
Just like any muscle car restoration, these issues need to be addressed since you are giving this car a new start on life. Knowing that there are these areas that need to be addressed will allow you to plan your time accordingly. This could keep you from ordering a conversion kit, or all of the components until you are ready.
8. Transmission Type
What type of transmission do you want?
Sounds pretty straight forward, right? Well, you do have the option to change from a manual to automatic transmission if that is what you want; however, I would stay with the transmission that was created for your vehicle. This will ensure mounting alignment, and that the speed sensor connected to your speedometer and odometer is already set to your final drive ratio and rolling wheel diameter.
There are 5 types of transmissions available for any vehicle: direct drive, transfer case, manual, automatic and CVT. For more information see Electric Vehicle Conversion Transmission Analysis and Selection.
9. Motor Selection
What type of motor current and how many?
There are a few things to be sorted out with motor selection. The natural first instinct would be to figure out how big of a motor you want to use. This is actually the second portion that needs to be selected. The first is whether the motor is alternating current, AC, or direct current, DC. Make sure you don’t just blast by this portion as this requires careful consideration. An AC motor has some advantages of being lighter, and less expensive but will require an AC-DC inverter since your batteries power are stored as direct current. The AC-DC invertor will add a little more weight, cost, and some complexity to the electric system. A DC motor has some advantages which include higher torque, and less complex motor control. The downside to a DC motor is the weight and cost. A DC-DC converter should be added to the system to regulate the voltage as well as provide a 12VDC supply for any accessories.
The third selection, and growing in popularity, is adding another motor coupled together to increase power further. Since the engine bay was originally designed deep enough for an engine, there is room for this option. Keep in mind that having two motors will draw twice the current and cut your range in half when compared to a single motor.
What Accessories do you need or want?
Once you remove the engine from the engine bay you will realize that a lot of sub systems rely on the engine running, so your air conditioning, vacuum powered brake assist, and power steering all run off the engine on the serpentine accessory belt. The serpentine belt/chain driven accessories can be retained by adding these the electric motor. The other option is to have a smaller motor dedicated to running all of the accessories when the vehicle is on. This would be a smaller version of the serpentine belt design.
11. Charging Plan
How do you plan to charge your electric vehicle?
The most common charging is level 2 which is 240VAC using a J1772 adapter. This adapter has been standardized by SAE international so that every automotive OEM uses the J1772. The main advantage to installing the J1772 adapter, if you needed more reasons, is that you could recharge at the Tesla charging stations that are rolling out across continental North America.
Additionally, there are more options for wireless charging now more than ever. Wireless charging can be installed in either your garage or driveway so that you simply need to drive over it to charge. This would need to be installed on your vehicle’s undercarriage by a distributor approved shop. See wireless charging by Plugless Power for more information.
Another option for charging is to use a regenerative braking system. This would require that the drive motor would be an AC motor, and have its poles reversed during braking.
Comment below on what are your goals that you have for your own electric car conversion?