Should You Build Your Own EV?

In a word, no. But, there are exceptions. Whey I built my own EV I started with a VW Rabbit. There were lots of reasons for this including:

  1. There really were no commercial alternatives
  2. An existing vehicle gives you so many pre-built pieces that you will need
  3. You already will have a title and something that has been registered to start with

Today, if you live in China there is no reason to do this. There are many choices that cost from $5000 to $10,000. Don’t think you can start from scratch and build something useful for less. You may have thought about importing something that is not available locally. Unfortunately, point 3 above is likely to limit that choice. This is particularly true of something with four wheels. In most jurisdictions the legal requirements for a 4-wheel vehicle are rather strict. One of the reasons you don’t see one of those “$2000 Chinese pickup trucks” available in the US is that it will not meet the safety requirements.

Depending on where you live it may also be hard to import a vehicle. Or, more accurately, you may need to have a license to import a car to, well, import a car. It turns out that is my situation.

Some of the less expensive cars (e.g., BYD Dolphin or Seagull) would fit my requirements (actually far exceed them) but they are not yet available here. The Dolphin is available in Costa Rica and I could probably drive it here with three or four recharges but crossing the borders into Nicaragua, Honduras, El Salvador and then Guatemala with a new car with no plates doesn’t sound like something a sane person would want to do. So, what to do?

I have had the idea to buy a TukTuk and convert it to electric for a while. What has slowed me down is finding a used TukTuk to use as a donated body. I continue to wait but here is why I think it would be pretty easy.

First, there is very little to a TukTuk beyond a frame, the bottom of a body and a soft top. You get steering, brakes, lights and a suspension. The drivetrain is pretty much a motorcycle motor and transmission driving a differential with CVJs (constant velocity joints) driving the wheels. So, you take all the drivetrain out and add a shelf at the top of the engine compartment for batteries. mount a controller somewhere and do one of these things to drive the wheels:

  1. Add a solid axle with differential driven by an electric motor (these items are easily available)
  2. Add Hub motors at each wheel (available but maybe not for 10 inch wheels)
  3. Add motors with chain drive at each rear wheel

Each approach has advantages and disadvantages. Item 1 means a fixed axle running across the whole back of the vehicle at the level of the wheel hubs. That adds weight and will limit the ground clearance. Item 2 is subject to availability but you could probably replace the wheels with something larger. Item 3 adds some unsprung weight at each rear wheel.

What I will do will depend on when a used TukTuk falls in my lap but, for now, it remains on my “future projects” list. It will probably stay there until a BYD Seagull appears on the local market.

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