Tesla Model S Battery Pack Teardown

We’ve heard a lot about the Tesla Model S over the last few years, it’s a vehicle with a habit of being newsworthy. And as a fast luxury electric saloon car with a range of over 300 miles per charge depending on the model, its publicity is deserved, and that’s before we’ve even mentioned autonomous driving  driver-assist. Even the best of the competing mass-produced electric cars of the moment look inferior beside it.

Tesla famously build their battery packs from standard 18650 lithium-ion cells, but it’s safe to say that the pack in the Model S has little in common with your laptop battery. Fortunately for those of a curious nature, [Jehu Garcia] has posted a video showing the folks at EV West tearing down a Model S pack from a scrap car, so we can follow them through its construction.

The most obvious thing about this pack is its sheer size, this is a large item that takes up most of the space under the car. We’re shown a previous generation Tesla pack for comparison, that is much smaller. Eye-watering performance and range come at a price, and we’re seeing it here in front of us.

The standard of construction appears to be very high indeed, which makes sense as this is not merely a performance part but a safety critical one. Owners of mobile phones beset by fires will testify to this, and the Tesla’s capacity for conflagration or electrical hazard is proportionately larger. The chassis and outer cover are held together by a huge array of bolts and Torx screws, and as they comment, each one is marked as having been tightened to a particular torque setting.

Under the cover is a second cover that is glued down, this needs to be carefully pried off to reveal the modules and their cells. The coolant is drained, and the modules disconnected. This last task is particularly hazardous, as the pack delivers hundreds of volts DC at a very low impedance. Then each of the sixteen packs can be carefully removed. The packs each contain 444 cells, the pack voltage is 24 V, and the energy stored is 5.3 kWh.

The video is below the break. We can’t help noticing some of the rather tasty automotive objects of desire in their lot.

Continue reading “Tesla Model S Battery Pack Teardown”

At Last, An Open Source Electric Vehicle From A Major Manufacturer

There is a rule of thumb to follow when looking at product announcements at the fringes of the motor industry that probably has something in common with crowdfunding campaigns. If the photographs of the product are all renders rather than real prototypes, walk away. It is said that small volume vehicle production is a space that attracts either crooks or dreamers, and parting with your money to either can be a risky business. So when yet another electric vehicle platform makes its debut it’s always worth looking, but too often the rendered images outnumber anything from the real world and you know you’ll never see one on the road.

It is with interest then that we note an exciting announcement made last week at CES, that the French carmaker Renault are to release an open-source vehicle platform. It is called the POM, and it is based upon their existing Twizy electric buggy platform. If this last point causes you to snort with derision because the Twizy is a tiny and not very fast in-line two-seater with awful weather protection better suited to the French Riviera than an American Interstate, remember that the car itself is not the point of this exercise at this stage. Instead the access to the technology will spark fresh innovation in the open electric vehicle sector that will transfer into better systems for more practical open source vehicles in the future. (Incidentally, we’re told by people who’ve tried the Twizy that it can be something of an unexpected gem to drive. It seems the lowish top speed doesn’t matter in the twisties when you have a low centre of gravity and quite impressive acceleration in a tiny machine.)

Partnered with Renault are OSVehicle, ARM, Pilot Automotive, a manufacturer of automotive accessories, and Sensoria, who will be working on wearable accessories. It’s probable that you won’t see many POMs on the road if you don’t live in a territory that already has the Twizy, but it’s certain you’ll see its technological legacy in other vehicles.

We’ve covered plenty of electric cars in the past here at Hackaday, and this isn’t the first one with an open source angle. We’ve had a very nice Mazda-derived ground-up build, and an astounding home-made hub motor.

Cheap Electric Car Drives Again with Charger Repair

If someone sent you an advert for an electric car with a price too low to pass up, what would you do? [Leadacid44] was in that lucky situation, and since it was crazy cheap, bought the car.

Of course, there’s always a problem of some kind with any cheap car, and this one was no exception. In this case, making it ‘go’ for any reasonable distance was the problem. Eventually a faulty battery charging system was diagnosed and fixed, but not before chasing down a few other possibilities. While the eventual solution was a relatively simple one the write-up of the car and the process of finding it makes for an interesting read.

The car in question is a ZENN, a Canadian-made and electric-powered licensed version of the French Microcar MC2 low-speed city car with a 72 volt lead-acid battery pack that gives a range of about 40 miles and a limited top speed of 25 miles per hour. Not a vehicle that is an uncommon sight in European cities, but very rare indeed in North America. Through the write-up we are introduced to this unusual vehicle, the choice of battery packs, and to the charger that turned out to be defective. We’re then shown the common fault with these units, a familiar dry joint issue from poor quality lead-free solder, and taken through the repair.

We are so used to lithium-ion batteries in electric cars that it’s easy to forget there is still a small niche for lead-acid in transportation. Short-range vehicles like this one or many of the current crop of electric UTVs can do without the capacity and weight savings, and reap the benefit of the older technology being significantly cheaper. It would however be fascinating to see what the ZENN could achieve with a lithium-ion pack and the removal of that speed limiter.

If your curiosity is whetted by European electric microcars, take a look at our previous feature n the futuristic Hotzenblitz, from Germany.

Massive 20-oz. Copper PCB Enables Electric Racing

Is twenty times the copper twenty times as much fun to work with? Ask [limpkin] and follow along as he fabricates a DC/DC block for a Formula E race car on 20-oz copper PCBs.

The typical boards you order from OSH Park and the like usually come with 1-ounce copper – that’s one ounce of copper cladding per square foot of board. For those averse to Imperial units, that’s a copper layer 34 micrometers thick. [limpkin]’s Formula E control board needs to carry a lot of current, so he specified 700-micrometer thick cladding, or 20-oz per square foot. The board pictured cost $2250, so you’d figure soldering on the components would be an exotic process, but aside from preheating the board, [limpkin] took it in stride. Check out the image gallery of the session and you’ll see nothing but a couple of regular high-wattage soldering irons, with dirty tips to boot.

It’s pretty neat comparing what’s needed for power electronics versus the normal small signal stuff we usually see. We’d recommend looking at [Brian Benchoff]’s “Creating a PCB in Everything” series for design tips, but we’re not sure traditional tools will work for boards like these. And just for fun, check out the Formula E highlights video below the break to see what this build is part of.

Continue reading “Massive 20-oz. Copper PCB Enables Electric Racing”

EV History: The Lightning Precedes The Thunder

In 1988, a bunch of engineers from Hotzenwald, Germany, came together and decided that it is time for the future of mobility: A new, more modern and environmentally friendly car should put an end to fossils and emissions while still being fun to drive. “It should become a new kind of car. Smaller, lighter, cleaner – and more beautiful” is how future CEO Thomas Albiez described his mission. For the first time in automotive history, this series car would be designed as an all-electric vehicle from the start and set a new standard for mobility. The project was given the codename “Hotzenblitz” (“Hotzen Bolt”) to indicate how the idea came to them: Like a lightning bolt. The snarky regional term also came with a double meaning: Imaginary lightning bolts, used for insurance fraud.

hotzenblitz_chassis
Hotzenblitz frame construction (origin unknown, image source)

Unnoticed by the rest of the world, they founded Hotzenblitz Mobile. Industrial Designer Harold Schurz was contracted to design the chassis for the Hotzenblitz, which was then modeled into a prototype chassis. The self-funded team moved fast. An external motorsports company helped to develop the tubular steel frame, and soon their vision took on shape. After the team had fitted a motor and transmission into the frame, CEO Thomas Albiez himself installed the traction battery and drive train. The team felt confident with the result, and in July 1990, during an open house day in the office, they somewhat spontaneously decided to call Green Tech entrepreneur and chocolate mogul Alfred Ritter.

Alfred Ritter had experienced financial losses after the Chernobyl Disaster. Many agricultural regions, including several hazelnut plantations that were vital to Alfred’s chocolate business, were irreversibly lost to the fallout contamination. It was then when he turned to the green energy business, founding the Paradigma group to manufacture solar collector systems and pellet heaters. When Thomas and the team called, Alfred jumped on the idea of an electric car. In the same year, Alfred Ritter and his sister Marli Hoppe-Ritter became shareholders in the company and helped to finance the future of the Hotzenblitz.

Continue reading “EV History: The Lightning Precedes The Thunder”

Lithium-Air Might Be The Better Battery

Researchers at Cambridge University demonstrated their latest version of what is being called the Lithium-Air battery. It can be more accurately referred to as a Lithium-Oxygen but Air sounds cooler.

The early estimates look pretty impressive with the energy density being 93% efficient which could be up to 10 times the energy density of Lithium-Ion and claims to be rechargeable up to 2,000 times.  Recent improvements toward Lithium-Air batteries include a graphene contact and using lithium hydroxide in place of lithium peroxide which increased both stability and efficiency.

Here’s the rub: Lithium-Air batteries are still years away from being ready for commercial use. There are still problems with the battery’s ability to charge and discharge (kind of a deal breaker if the battery won’t charge or discharge right?) There are still issues with safety, performance, efficiency, and the all too apparent need for pure oxygen.

Do batteries get you all charged up? Check out our coverage of MIT’s solid state battery research, or have a look at the Nissan Leaf and/or Tesla battery packs.

Thanks to [Jimmy] for the tip.

Hackaday Links: September 20, 2015

Here’s an offer from Intel and the guy behind all of reality TV [Mark Burnett]: win a million dollars for making something. Pitch an idea for wearable electronics to the producers by October 2, and you might be on a reality TV show about building electronics which they’re calling America’s Greatest Makers. With this, Intel is promoting the Curie module a tiny, tiny SoC with Bluetooth, IMU, and DSP functions. We’re of the opinion that a Hackaday reader should win this contest, or at the very least be featured prominently in the show. No, it’s not Junkyard Wars, but it’s still a million dollar prize.

[Jeremy] builds bombs clocks, and he has a Kickstarter for an interesting Nixie clock. Most Nixie tubes have digits, but [Jeremy] is using the IN-9 ‘bar’ tubes for the hour and minute hand.

The Luka EV is a semifinalist for the Hackaday Prize, and a completely open, road legal electric vehicle powered by hub motors. It also looks really, really cool.  Now, they’re selling them. It’s €20,000 for a complete car. Did I mention how cool it looks?

Boca Bearings is having a ‘Show Us Your Workshop’ contest, with the best (or should it be worst?) workshop winning tool cabinets, tool kits, a work mat, and calipers.

The EMU Drumulator is a classic drum machine that featured dirty 12-bit drum sounds in ROM. Now, it’s a single chip thanks to [Jan]. He’s done a lot of great work putting synths in single chips, and it’s great to see him move on to classic drum machines.

Offered without comment, here’s a ride through a PCB.