So you’ve been salivating over the Tesla 3 and the AUDI e-tron or you’re saving up for a NISSAN Leaf. But what about it? Are you buying the car because it’s the iPhone of the automobile world? Because you believe you are saving planet earth? It’s time to understand some of the terms used in Electric vehicles and what they mean to you.
Yes it’s the same as you already have in your car. Except that the acid or gel based batteries we are used to are too bulky, too heavy and don’t offer anywhere close to the storage required by cars that use it for traction. Current technology offers Lithium ion battery packs as a solution. The same technology that powers your phones and laptops is now scaled up. Most cars now have a battery of batteries with power capacity in the hundreds of kilowatts.
AC or DC motor?
You’ve seen electric vehicles before. Forklifts, golf carts and wheelchairs. They’re usually low range, low speed and used low cost DC motors. Now, with the need for low weight, higher efficiency, low maintenance and regeneration, AC induction motors are preferred. Another aspect is that the electric motor has now migrated from its position on the hub of the wheel, ergo hub motors, to a central point on the axle complete with electronic differentials.
Range or Autonomy
This will be sold to you as the unique selling proposition on latter day vehicles. A 500 km range is usually considered rather decent and sufficient to take care of a day’s commute before you recharge. However do check whether the range is NEDC based or the newer WLTP standard, since the NEDC is more wishful thinking while the WLTP is closer to real life.
Not to be confused with the term used to indicate range. While it’s not exclusive to electric vehicles, we will find much more incidence here because the two systems work well in tandem. That’s why Tesla has been pushing the virtues of their self driving cars. The technology isn’t mature yet and depends to a great degree on proper road signage, lane markings and an orderly traffic flow. However most car companies are offering bits and pieces including automated parking and intelligent cruise control. Watch the space on the topic because you may want to buy a car you never want to drive yourself.
That’s another mission critical feature. The longer it takes for you to recharge your car, the less likely you are to take impetuous driving decisions. If you need 8 hours, you’ll only charge at home or office. Most manufacturers now offer fast chargers of higher capacities that can bring your car above the 75% mark in under an hour. Higher voltages, use of capacitor banks and better batteries allow this. We feel that the actual tipping point in terms of real world use will be when recharging to that reasonable full mark happens in under ten minutes. That’s when fuel pumps will double up as recharge points.
Going electric to go green
Not so soon. Hold your horses. If you already own a normal car using a Petrol or Diesel engine, the cleanest option is to use it as long, as frugally and as cleanly as possible. Maintenance, care and rationalisation of usage will save far more CO2 than rushing to replace your car.
Don’t believe the company when it tells you that the battery pack will last the life of the car. It may last as long as you own it, but battery capacity degrades over use. That’s why you have to replace your phone’s battery. On second thought what are we talking about? You very likely upgrade your phone every two years. We just can’t see the public doing the same for a $30,000 car. Many companies are investing in businesses that are centered on using end of life batteries, usually as power banks in tandem with renewable energy networks. The catch is the cost of replacing the batteries is a large and significant part of long term ownership cost. Let’s see how that works out.
Voltage versus wattage
Wattage represents the power of a system. In short it’s a fixed ratio off horsepower or PS or the likes. Voltage of the system however is linked more to how efficiently that power is handled. Higher voltage systems require technology and investment as well as costlier charging stations although the trade off is in the ability to charge faster and store more watts as well as to deliver more power to the wheels.
Single motor, two, three or four
That’s largely dictated by the layout of the transmission. Four motors usually indicate one per wheel. Three could mean a large central unit on one axle and the smaller hub motors on the wheels of the other axle. Then come one or two motors. That usually means a motor on the relevant axle. Here it’s important to see the total power of all the motors to decide which is more powerful.
With electric motors it’s possible to effect braking by loading the motor. The motor then feeds wattage back into the battery pack for use when accelerating thereby increasing the efficiency of the system.
When having an internal combustion engine as well doesn’t make a hybrid
Yes. You could have an electric car with a small IC engine. If the engine drives the wheels you have a hybrid. If the engine only switches on to charge up the batteries it’s called a range extender. We will see fewer of these, well, ‘hybrid’ systems as battery only range improves.
Well, that’s enough for a day. If you think we’ve missed anything significant do leave a comment so that we can flesh this out. You could also tell us which electric car you want to buy. As for us, we’re waiting for a car with ten minutes recharge tops.