When Jeffrey Brian “JB” Straubel built his first electric car in 2000, a modified 1984 Porsche 944, powered by two beefy DC motors, he did it mostly for fun and out of his own curiosity for power electronics. At that time, “EV” was already a hype among tinkerers and makers, but Straubel certainly pushed the concept to the limit. He designed his own charger, motor controller, and cooling system, capable of an estimated 288 kW (368 hp) peak power output. 20 lead-acid batteries were connected in series to power the 240 V drive train. With a 30-40 mile range the build was not only road capable but also set a world record for EV drag racing.
The project was never meant to change the world, but with Tesla Motors, which Straubel co-founded only a few years later, the old Porsche 944 may have mattered way more than originally intended. The explosive growth between 2000 and 2010 in the laptop computer market has brought forth performance and affordable energy storage technology and made it available to other applications, such as traction batteries. However, why did energy storage have to take the detour through a bazillion laptop computers until it arrived at electro mobility?
You certainly won’t find that grail of engineering by just trying hard. Rather than feverishly hunting down the next big thing or that fix for the world’s big problems, we sometimes need to remind ourselves that even a small improvement, a new approach or just a fun build may be just the right ‘next step’. We may eventually build all the things and solve all the problems, but looking at the past, we tend to not do so by force. We are much better at evolving our ideas continuously over time. And each step on the way still matters. Let’s dig a bit deeper into this concept and see where it takes us.
Winner of the third place in last year’s Hackaday Prize was [Chris Low]’s Light Electric Utility Vehicle. In case you think that once a Hackaday Prize is in the bag then that’s it and the project creator packs up and goes home, [Chris] dispels that idea, he’s invested his winnings straight back into his project and posted his latest progress on an improved Mk3 model.
We first covered the Light Electric Utility Vehicle back in June 2015 when it was first entered for the 2015 Hackaday Prize. The aim was to produce a rugged and simple small electric vehicle that could be powered by solar energy and that was suitable for the conditions found in South Sudan, where [Chris] works. The vehicle as we saw it then was an articulated design, with chain drive to bicycle-style wheels. The Mk3 version by comparison has lost the articulation in favour of rack-and-pinion steering, has in-hub motors instead of chain drive, and now features coil-spring suspension. You might comment that it has lost some of its original simplicity and become something more like a conventional electric UTV, but along the way it has also become more of a practical proposition as an everyday vehicle.
What’s a smart city? According to Wikipedia, a smart city uses ICT (information and communication technologies) to enhance quality, performance, and interactivity of urban services while reducing costs and resource consumption. Hackers have been using technology to enhance all sorts of things for years.
A fortuitous circumstance landed [Michal] the crown jewel of the Tesla Model S – the 310kW, 590Nm drive train. Exactly how and where [Michal] landed this gigantic powerful motor is a question that remains unanswered, and the question unasked. We might not want to know.
Now that he has a motor, the name of the game is figuring out how to drive it. Usually that means capturing data from the CAN bus and replaying that data. This isn’t what [Michal] is doing; instead, he’s using a motor controller he developed for the Chevy Volt and Toyota Prius. It’s going to be a lot of work, but that’s only because these gigantic EV motors and controllers are pretty rare on the used market now. Give it a few years, and the work [Michal] is putting in now will pay off in hundreds of DIY electric vehicles.
In the future, just about everyone will be driving an electric car. We’re seeing the beginnings of this, and that means electrics and hybrids are showing up in junk yards. What does that mean? Tons of big batteries and powerful motors to build an electric vehicle from recycled parts.
A few years ago, someone exceptionally smart did the math on the environmental friendliness of different makes of vehicles from cradle to grave. The most environmentally friendly car to buy wasn’t a Prius, Leaf, or Tesla, but a used car; an old Civic or Rabbit. The logic makes sense – after two or three hundred thousand miles under its timing belt, the Civic or Rabbit has already paid the cost of forging the body and refining the plastic. Obviously, then, the most environmentally friendly car would be reusing the batteries and motor out of a newer hybrid.
For his Hackaday Prize build, [mauswerkz] is taking a 2001 BMW 330ci coupe and replacing the motor and transmission with some salvaged EV equipment. In this case, it’s the transmission and inverter from a Lexus GS450h and the batteries from a Chevy Volt ‘Extended Range’. Where the magical junkyard [mauswerkz] is pulling this equipment out of is anyone’s guess, but he did it. Maybe you can too.
So far, [mauswerkz] has the charger out of the Chevy Volt hooked up to the inverter and transmission from the Lexus and is making stuff turn. It’s only running at 200V instead of the final voltage of 650, but it’s enough for a proof of concept. Now it’s just a matter of stuffing everything inside the BMW.
Of course going to a junk yard isn’t the only way to get an EV. The more enterprising builder might want to build their own EV completely from scratch, starting with a block of foam. Yes, it even looks better than the BMW.
The Luka EV from [MW Motors] had a few project aims: it should be all-electric, naturally, with a top speed of 130km/h or 80mph. It should have a range of over 300km, and it should look good. That last line item is tricky; it’s not too hard to build an electric car, but to make one look good is a challenge.
The design of the car actually started out as a digital file. A large block of foam was acquired and carefully carved into the desired shape. This foam is covered fiberglass, and parts are pulled off this fiberglass mold. This is a great way to do low-volume production – once the molds are complete, it’s a relatively simple matter to build another body for a second Luka EV.
With all the lights, accessories, windows, and trim installed, it’s time to put this body on a chassis. This was welded out of square tube and serves as a test rig that can be independent of the mess of fiberglass. In the chassis are batteries, suspension, motor controllers, and wheels loaded up with hub motors. It works well, even with one motor.
There’s a lot more to this project, including a great guide on building a road legal car in the UK. The team isn’t based in the UK, but it’s a much more friendly environment for ‘small series’ vehicles. The requirements are easy to meet – “have a horn”, for example – but there are a lot of them.
[Jay] got a pretty good deal on a low milage Nissan Leaf battery. Unfortunately, it came wrapped in a wrecked Nissan Leaf. There are more and more electric cars on the road each year, and that means there are more cars coming off the road as well due to accidents. Electric cars are specifically designed to protect their batteries, so as we’ve seen before with Tesla vehicles, a salvage car often will still contain a serviceable battery pack. [Jay] used this knowledge to his advantage, and walks us through his experience buying, testing, and dismantling Hoja, his very own salvage Leaf.
[Jay] set up an account on Copart, an auto salvage auction website here in the USA. “Live” online Auto auctions tend to work a bit differently than E-bay, so [Jay] walks us through the process of buying the car, and gives some tips for getting through the process. [Jay’s] particular car was delivered to him on a trailer. It had been rear ended so hard that the rear tires were not usable. The car was also electrically dead. Thankfully, the electrical problems turned out to be a discharged 12 volt accessory battery. A quick charge of the accessory battery caused the Leaf to spring to life – and display a ton of trouble codes. [Jay] cleared the codes with his trusty OBD II scanner, and the car was ready to drive, at least as much as a wrecked car can drive. It did move under its own power though – with the rear end riding on dollies.
Now that the battery was known to be good, [Jay] set about liberating it from its crushed Leaf cocoon. Nissan’s service manual assumes one would be doing this with a lift. [Jay] had no such luxuries in his driveway, so he used 3 floor jacks to lower the 600 lb battery and dollies to pull it out from under the car.