## How much range can an electric vehicle conversion get?

Electric vehicle conversion range is determined by the efficiency of the vehicle, the system voltage, and the system amp hour rating.

Let’s try to figure out the range for the 1970 Volkswagen Beetle. So the first step is determining the efficiency of the vehicle. Vehicle efficiency is essentially a measure of how easily your vehicle moves accounting for weight, aerodynamics, and rolling resistance. This is measured in Watt-hours per mile or Wh/mi. It’d be really tough on paper to calculate the hypothetical Wh/mi of our conversion so instead we can find someone else with a similar conversion and use their Wh/mi as an approximation for our own.

A good place to look is EValbum which is a collection of a bunch of electric vehicle conversions uploaded by people who have converted cars themselves. I did a quick search for “beetle Wh/mi” and found this one. A 1973 Super Beetle converted by Jon Glauser. He’s added his Wh/mi of 262Wh/mi, his build is a bit different from what ours will end up being, but this is a good starting point.

Next we need to get our system voltage. With our Warp 9 motor, we know we can use up to an 170V system, but we shouldn’t max the motor out as Netgain says that 170V continuous can cause issues. We’ve already approximated that we should be able to reach 60mph at around 120V, but let’s say 144V to be safe. So we’ll set that as our system voltage for now.

So what do we want our range to be? Well let’s say this is a short commuter car we’d like to drive it roughly 60 miles. Using our approximated efficiency rating, and our desired range we can figure out how much power in kilowatts we’ll need to achieve that range.

Here’s the equation:

**Efficiency x desired range = energy required to reach that range**

So plugging in our numbers:

262Wh/mi x 60 mi = 15,720 Watts or 15.7kWh (kilowatt hours)

So 15.7kWh is the amount of energy we’ll need over time to get the range we want. We already know our system power will be 144V so, now we need to know how much battery we need. This is measured in Amp hours or Ah, to get the needed Ah we’ll divide the energy needed by our system voltage.

Here’s the equation:

**Energy required to reach desired range / system voltage = How much battery we need in Ah**

So plugging in our numbers:

15,730 Watts / 144V = 109.23 Ah (let’s round it up to 110 Ah)

So, for our motor to get up to the speed that we want we’ll be using an 144V system. To get a range of 60 miles our system will need to be roughly 110 Ah. But there are some things to consider depending on the type of battery you’ll be using. Most batteries should not be fully discharged so we should account for some added energy need so we never actually fully discharge our batteries. For this example let’s assume we’re using lithium-ion batteries because they’re the best. To account for this we’ll multiply our Ah by 1.32.

110 Ah * 1.32 = 145.2 Ah (or just 145 Ah)

So there we have it. These two numbers are the two most important when figuring out your battery setup. With these two numbers we can begin to test different configurations of batteries to achieve the power, and range we require.

We need 144Ah and 144V.