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EV Background Page

This page provides a quick discussion of what an EV is, and some thoughts to consider about them. Since this is well trodden ground, I am not going to get very specific, and I will focus on describing things as I see them. Refer to the EV Reference Material section for further, unbiased (or at least differently biased) reading.

What is an EV?

EV stands for "Electric Vehicle". EV's can be found in all shapes and sizes, including:

  • golf carts and utility vehicles used in factories, warehouses, and airports. They fit their niche well, but are not meant for road use.
  • scooters and 3-wheelers designed for urban/around town use. If you have a Vespa, moving to one of these might work well for you.
  • NEV's (Neighborhood electric vehicle). These are legally limited to use on urban and side streets and federally limited to a maximum of 25mph, but some states (Including Washington) allow 35mph. Basically a street-legal, glorified golf cart, but useful if you do a lot of low speed driving. Performance can be upgraded.
  • Older Production electric vehicles. There are been small runs of production electric pickup trucks and passenger cars over the years. 99% of these were sold to fleet buyers. A few are still floating around. Mostly these used the same chassis as their gas counterparts, and could easily be mistaken for an ordinary vehicle.
  • Prototypes and New Designs: There are a whole slew of modern compact EV's and concept vehicles, running the range from small commuters to exotic sports cars that are on the market, or claim to be available shortly. A whole mess of them are starting to come out of China. These are designed from the ground up and are more distinctive. They come from well known manufacturers and new startups. Examples include the Tesla Roadster (a BEV), the Corbin Sparrow (3 wheeler, licenses as a motorcycle), the ZAP (a Chinese NEV) and Chevrolet Volt (a PHEV).
  • EV Conversions. These vehicles started life as an ordinary cars and trucks. The internal combustion components were removed, and electric drivetrain was installed. The conversions usually look like any ordinary car (except for the usually-left-leaning political stickers emblazoned all over them). These conversions are mostly performed by normal people like myself, or shops that specialize in performing conversions. Common conversions include Geo Metro's, VW Rabbits, Porchse 914's, and small pickup trucks, but you can find all types.

EV's are Sometimes also referred to as BEV's, for "Battery Electric Vehicle", which describes a vehicle whose sole source of energy is onboard batteries. This differentiates them from other, more recently developed vehicle types such as Hybrids (Gas and Electric motor working in unison, but the gas engine is dominant) and PHEV's "Pluggable Hybrid Electric Vehicles". PHEV's have gas and electric drive components like regular hybrids, but the electric drivetrain components are dominant. They are capable of doing a significant amount of driving using only electric power, and they can be recharged from the grid when not being driven. The gas engine kicks in when the batteries get low or if extra power is needed.

What can an EV Do?

Performance?

The performance characteristics of an EV will depend on what type of EV it is of course. NEVs and scooters are fine for running around town but top out at 25 to 35mph so are no good for the freeway. Those Factory built EV's from the 90's all have plenty enough oomph for highway driving, though they may not be hot rods. The new super-EVs such as the Tesla have performance characteristics on par with any European supercar that nobody can afford either.

For EV conversions, it is harder to quantify since each one is unique and was built to meet a compromise of all the builder's requirements: Performance, range, cost, etc. However, any halfway decent conversion will be able to run at freeway speeds, though again it may not be a hot rod. You can look at my EV Performance Analysis page to start getting some ideas what can be expected from a given conversion.

Range?

People throw out a lot of numbers for the range of an EV, and often qualify that range with a lot of conditions. I'm guilty of it too: Throughout this website I talk about both Theoretical range and Useful or Practical range. Basically, Theoretical range is a mathematical calculation of the maximum possible distance an EV could go, completely draining its batteries under some kind of well-defined optimal driving conditions. Theoretical range is a good way to perform an apples-to-apples comparison between EVs but it is not the number you need to look at if you want to determine if an EV will meet your daily driving needs. That number is the Practical range. This number is a bit more difficult to quantify as you have to figure in how deeply you wish to discharge your batteries (80% is the limit for lead acid without severely reducing lifespan) and what your driving conditions are (flat or hilly, windy or calm, stop-and-go or cruise, etc). But a good rule of thumb is that the Practical range is about half what the theoretical range is.

EV scooters and motorcycles may only have a useful range of 10 or 20 miles. NEV's will probably be able to go 40 miles or so. (All of this at speeds under 35mph of course). Older Production EV's have ranges that vary from 40 or so (many of the S-10 and Ford Ranger pickups, for example get around this range) miles up to 100 miles (Some Toyota RAV4 EVs can still hit 100 miles on a charge). Not too bad considering the batteries in these cars are nearing 10 years old. The aforementioned EV Supercars like the Tesla with lithium batteries are looking at 200 miles or more of range.

As with performance, range is likely to be most variable with an EV conversion due to the uniqueness of each vehicle. But again, a quick survey of the car insofar as type and quantity of batteries, drivetrain, and body style can let you get a pretty good idea of what sort of range you can expect from it. Climate and battery box design can be a factor too. Again, nauseating details at the EV Performance Analysis page. But long story short, it is possible for a good homebuilt EV to achieve 40 miles or more of useful range.

Tradeoffs

Note that with EV conversions, assuming the car uses lead acid batteries as 95% of them do, the biggest tradeoff you have to deal with is range versus performance. To get range, you need lots of batteries (and thus weight), and you will probably want to use flooded batteries as they are the most energy dense lead acid technology. If you want performance you will need to use lighter, but far more powerful AGM batteries. Reduced weight and increased power means much better performance. However AGM batteries are less energy dense than flooded batteries, so you will have traded a significant fraction of your range for that performance. So with the state of EV conversion technology right now, you really can't have both range and performance, unless you can afford to spend lots of money on lithium batteries. See my EV Battery Considerations page for more details on the tradeoffs with lead acid batteries.

Which one works for me?

... And I do mean ME. Your needs may be different from mine, but here is my thinking:

EV's that are roadable and affordable to mere mortals such as myself fall into a couple of the categories I described above: Scooters/3-wheelers, NEV's, and EV conversions. I don't want a vehicle that doesn't have performance at least as good as my 1962 Land Rover (not a high bar to clear). This rules out the 35-mph NEV's. I don't need a scooter or small powered vehicle, because I've already got a good commuter in my Redline Monocog bicycle. So the only way to go for me is a conversion.

If you read my EV Chassis Selection page, you know that the gap that needs to be filled for me is a second car, able to handle all around-town driving and able to carry at least a full load of groceries and two people. I want a car that is optimized for range. I can do with a useful range of 40 miles, but I'd like it to be more if possible. It will have some cargo space though much of it may be taken by batteries. It will have adequate acceleration and a top speed sufficient for freeway use. These are adequate specs for a second car, but probably won't work for most people as their only car, and that is true for me as well. I've still got my 1962 Land Rover for longer range trips and heavy hauling.

See my EV First Impressions page for a discussion of how well my Toyota MR2 EV is doing in meeting my needs.

Build, Buy, or Commission?

Why buy?

I suppose it is easier. Plunk down $15000 to get an NEV. Plunk down anywhere from $2000 to $30000 to get somebody else's EV Conversion, but remember what they say about getting what you pay for, and remember that each conversion is a "snowflake" (unique) which can cause problems if you ever need to maintain or modify it. Plunk down a few thousand to get an EV Scooter. Plunk down $80000 and up and you get a Tesla Roadster once they actually start selling them. Assuming they ever sell the Chevy Volt or other PHEV's, it could easily cost $30000 or more. Yikes. If you have more money than time or an off-the-shelf machine fits what your needs are, then this might be a very good way to go. If you aren't technically inclined, this may be the only way to go. In that case, you might also want to avoid purchasing someone else's conversion. In my case, I'm a cheapskate, I am very technical, and I always want to mess with my stuff. Off-the-shelf never does quite what I want.

Buying someone else's conversion, if you are patient, may be the least expensive way to get into a freeway-capable EV. The best way to go here is probably to wait for a newer EV conversion to come up on the market with spent or damaged batteries. (It is common for people to push the batteries beyond their limits one too many times, and give up on the car) Assuming the batteries aren't anything weird or exotic, you will be able to buy the car at a good (non-running price) and simply replace the batteries to be up to full speed again. But you do need to do your homework to know what the car is capable of (and thus if it will meet your needs) before buying it. Also with a conversion you need to have an eye towards how well the conversion was done. Workmanship can range from downright dangerous with bailing wire and duct tape all the way to well designed with obsessive-compulsive attention to detail, so keep your eyes open. The best place to look online for EV conversions for sale is at the Austin EV trading post: http://www.austinev.org/evtradinpost/ They also pop up on ebay fairly regularly. I mentioned it before, but I will do it again: If you are not technically inclined and you don't have any buddies who are (and can be bribed with beer, or whatever), buying a conversion may not be the way to go for you simply due to the uniqueness of each car.

Why build?

The minimum cost to build an EV, starting with a gas-powered donor car or "glider" (a rolling chassis) that is in good condition, is about $6000, that assumes scrounging used parts and making deals wherever possible, maybe even buying a donor EV with a wrecked or rusted body to get the major parts. My conversion (detailed on my EV Project Expenses page, using a mix of new and used parts) cost about $11000.

There are many personal reasons one might want to build an EV. People do it for political reasons, Or because they want to do their part to reduce pollution by recycling a dead car and reducing their carbon footprint. Other people build them for competition or purely for the technical challenge of it. In my case, the techical challenge and opportunity to have a unique vehicle that uses no gas was the biggest motivator here.

Right now it is very expensive to actually buy a factory built EV (New or any late model) with sufficient performance for highway usage. New, factory made vehicles that are on the market or claim to be shortly are $50,000 and up. For $20,000 you can build a very good performing conversion. For that $6,000 to 10,000 you can build a conversion that performs well enough for highway usage. Basically, right now it is much cheaper to build a conversion yourself than to buy any Factory made EV. You may be able to buy someone else's conversion for a bit less than you would spend replicating it, but likely not much less if the car is well done and in good condition.

Why Commission?

If you can't afford a Tesla, and you can't find someone else's conversion that does what you want, and you don't have the time or skill set to build a car yourself, it may be possible to hire someone to do it for you. There are people (often working out of their own garages) who specialize in converting cars to Electric. Often they will specialize in a particular type of car. For example, in Seattle where I live there is a very well known fellow who does Geo Metro conversions. Expect the cost to be the cost of materials, plus a reasonable amount of labor for the work. Assuming you are commissioning this person to do a car they are experienced with converting, and the car is in good condition you will probably be looking at a couple hundred hours worth of labor. If you choose to go this route, first of all look at as many recent examples of their conversions as possible (without this person present) and ask their owners of their impressions of their cars and the person who did the conversion. Since presumably you are commissioning the car to be done because you either cannot do it yourself or don't have time, chances are when it needs work this person is who you will take it back to, so it will be a long term relationship. Also, I would not recommend commisioning a car to be done by someone who has no experience with EVs even if they are technical, or even someone who does EV conversions but is not experienced with your chosen car. There are just too many things that can go wrong that will blow out either the scope or the cost of the project. Your best bet for finding someone who does EV conversions for others is to start attending local EVA meetings.