Reverse Engineering A Nissan Leaf Battery Pack

June 16, 2016 by Jenny List 36 Comments

Batteries wear out. If you are an electric vehicle enthusiast, it’s a certainty that at some time in your not-too-distant future there will be a point at which your vehicle’s batteries have reached the end of their lives and will need to be replaced. If you have bought a new electric vehicle the chances are that you will be signed up to a leasing deal with the manufacturer which will take care of this replacement, but if you have an older vehicle this is likely to be an expensive moment.

Fortunately there is a tempting solution. As an increasing number of electric vehicles from large manufacturers appear on our roads, a corresponding number of them have become available on the scrap market from accident damage. It is thus not impossible to secure a fairly new lithium-ion battery pack from a modern electric car, and for a significantly lower price than you would pay for new cells. As always though, there is a snag. Such packs are designed only for the cars they came with, and have proprietary connectors and protocols with which they communicate with their host vehicle. Fitting them to another car is thus not a task for the faint hearted.

Hackaday reader [Wolf] has an electric truck, a Solectria E10. It has a set of elderly lead-acid batteries and would benefit hugely from an upgrade to lithium-ion. He secured a battery pack from a 2013 Nissan Leaf electric car, and he set about reverse engineering its battery management system (BMS). The Solectria will use a different battery configuration from the Leaf, so while he would like to use the Leaf’s BMS, he has had to reverse engineer its protocols so that he can replace its Nissan microcontroller with one of his own.

His description of the reverse engineering process is lengthy and detailed, and with its many photos and videos is well worth a read. He employs some clever techniques, such as making his own hardware simulation of a Li-ion cell so that he can supply the BMS known values that he can then sniff from the serial data stream.

We’ve covered quite a few EV batteries here at Hackaday. Quite recently we even covered another truck conversion using Leaf batteries, and last year we featured a Leaf battery teardown. We’ve not restricted ourselves to Nissan though, for example here’s a similar process with a Tesla Model S pack.

Hackaday Prize Entry: Tearing Down A Tesla

June 16, 2015 by Brian Benchoff 21 Comments

We’ve seen a few people tear down the drive trains from electric vehicles like the Nissan Leaf, Prisuses, or the Chevy Volt. We’ve also seen someone tear down the battery pack found in a Tesla Model S. What we haven’t seen until now is a reverse engineering of the Tesla Model S drive train.

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.

The 2015 Hackaday Prize is sponsored by:

Hackaday Prize Entry: A Light Electric Utility Vehicle

June 7, 2015 by Brian Benchoff 32 Comments

[Chris] lives in South Sudan, where there are a lot of poor areas with terrible infrastructure. One of the bigger challenges for this area is getting people and materials over roads that are either bad or don’t exist. Normal vehicles aren’t built for the task, and a Hilux or Land Cruiser is much to expensive. For his Hackaday Prize entry, [Chris] is building a rugged low-cost utility vehicle platform for the developing world.

This battery-powered, four-wheel cart is made out of what [Chris] could find. The frame is made out of 50x50mm angle iron that’s welded together, with the body panels fabricated out of 1200x2400x1.2mm sheet that’s sourced locally. While [Chris] would like better wheels, the cheap Chinese motorcycle wheels are everywhere and cheap – $65, which includes the bearings, breaks, and sprockets. It even has higher ground clearance than the Land Cruiser.

[Chris] already has a prototype of his project built and it’s rolling around. You can check out a video of that below.

The 2015 Hackaday Prize is sponsored by:

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Hackaday Prize Entry: An Electric Vehicle From Recycled Parts

May 27, 2015 by Brian Benchoff 49 Comments

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 2015 Hackaday Prize is sponsored by:

Hackaday Prize Entry: Building A Car, From Scratch, Out Of Foam

April 30, 2015 by Brian Benchoff 20 Comments

Want an impressive example of what a few people can do in a garage? How about building an electric car, from scratch, starting with a gigantic chunk of foam?

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.

Already the car is beautiful, and that’s just with it sitting on a trailer. We can’t wait to see this thing hit the road.

The 2015 Hackaday Prize is sponsored by:

Odd-Looking Mini EV Yard Tractor Is Made From Plywood And Bike Parts

January 12, 2015 by Rich Bremer 24 Comments

[Ian] likes to build small Electric Vehicles and his most unique project is certainly this yard tractor. During the design phase of the project [Ian] came up with a few requirements to ensure that this vehicle would be useful around the house. First, it had to be maneuverable in tight spaces. This was accomplished by the short wheel base and small diameter front-steering wheels. Next, it had to get great traction as leaving torn-up grass around the yard was not going to cut the mustard. Four mountain bike drive wheels used in the rear double the traction while at the same time distributing the friction over twice the surface area of the grass. To increase the traction even more, the rider’s seating position was intentionally put directly over the rear wheels.

The frame was kept simple by using plywood as structural members. Two 40Ah 12v batteries are set low between the front and rear axles and power the 4 DC drive motors. The motors are connected to the axle by means of sprockets and chains which results in a 36:1 reduction. That’s a large gear reduction and limits the tractor to a top speed of 12 km/h (7.5 mph). Bike tires front and rear were used because they are easily available and are super low-cost. And of course, a tractor wouldn’t be complete without a trailer hitch to tow around plants, rocks, wood or any other general yard debris.

[Ian] makes plans for his mini EV tractor available on his website. If your kid is envious of this electric tractor, maybe you can make him one of these…

Electric Bubblegum Board

October 20, 2014 by Marsh 17 Comments

The Mini Maker Faire in Atlanta was packed with exciting builds and devices, but [Andrew’s] Electric Bubblegum Boards stood out from the rest, winning the Editor’s Choice Award. His boards first emerged on Endless Sphere earlier this summer, with the goal of hitting all the usual e-skateboard offerings of speed, range, and weight while dramatically cutting the cost of materials.

At just over 12 pounds, the boards are lightweight and fairly compact, but have enough LiFePO4’s fitted to the bottom to carry a rider 10 miles on a single charge. A Wii Nunchuck controls throttle, cruise control, and a “boost” setting for bursts of speed. The best feature of this e-skateboard, however, is the use of 3D-printed parts. The ABS components not only help facilitate the prototyping process, but also permit a range of customization options. Riders can reprint parts as necessary, or if they want to just change things up.

[Andrew’s] board is nearing the 11th hour over at his Kickstarter page, so swing by to see a production video made for potential backers, or stick around after the break for some quick progress and demo videos.

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