Lithium Mine To Battery Line: Tesla Battery Day And The Future Of EVs

September 14, 2021 by Maya Posch 15 Comments

After last year’s Tesla Battery Day presentation and the flurry of information that came out of it, [The Limiting Factor] spent many months researching the countless topics behind Tesla’s announced plans, the resource markets for everything from lithium to copper and cobalt, and what all of this means for electrical vehicles (EVs) as well as batteries for both battery-electric vehicles (BEVs) and power storage.

A number of these changes are immediate, such as the use of battery packs as a structural element to save the weight of a supporting structure, while others such as the shift away from cobalt in battery cathodes being a more long-term prospective, along with the plans for Tesla to set up its own lithium clay mining operation in the US. Also impossible to pin down: when the famous ‘tabless’ 4680 cells that Tesla plans to use instead of the current 18650 cells will be mass-produced and when they will enable the promised 16% increase.

Even so, in the over 1 hour long video (also linked below after the break), the overall perspective seems fairly optimistic, with LFP (lithium iron phosphate) batteries also getting a shout out. One obvious indication of process to point out is that the cobalt-free battery is already used in Model 3 Teslas, most commonly in Chinese models.

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Tesla Automatic Driving Under Scrutiny By US Regulators

August 16, 2021 by Al Williams 66 Comments

The US National Highway Traffic Safety Administration (NHTSA) has opened a formal investigation about Tesla’s automatic driving features (PDF), claiming to have identified 11 accidents that are of concern. In particular, they are looking at the feature Tesla calls “Autopilot” or traffic-aware cruise control” while approaching stopped responder vehicles like fire trucks or ambulances. According to the statement from NHTSA, most of the cases were at night and also involved warning devices such as cones, flashing lights, or a sign with an arrow that, you would presume, would have made a human driver cautious.

There are no details about the severity of those accidents. In the events being studied, the NHTSA reports that vehicles using the traffic-aware cruise control “encountered first responder scenes and subsequently struck one or more vehicles involved with those scenes.”

Despite how they have marketed the features, Tesla will tell you that none of their vehicles are truly self-driving and that the driver must maintain control. That’s assuming a lot, even if you ignore the fact that some Tesla owners have gone to great lengths to bypass the need to have a driver in control. Tesla has promised full automation for driving and is testing that feature, but as of the time of writing the company still indicates active driver supervision is necessary when using existing “Full Self-Driving” features.

We’ve talked a lot about self-driving car safety in the past. We’ve also covered some of the more public accidents we’ve heard about. What do you think? Are self-driving cars as close to reality as they’d like you to believe? Let us know what you think in the comments.

Tesla’s Megapack Battery Burned For Days In Grid Storage Fire

August 12, 2021 by Lewin Day 174 Comments

Lithium rechargeable batteries have been heralded for their high-density energy storage, enabling all manner of technologies to come to fruition. From drones to practical electric cars to large-scale grid storage, the applications are endless.

The fire as seen from a drone overhead. Source: Twitter/@FireRescueVic

However, the lithium rechargeable battery has always had one major flaw–flammability. Pushed outside their operating range or otherwise tipped into thermal runaway, and they can burn ferociously as a result.

This came to pass in late July, at the Victorian Big Battery in Geelong, Australia, and it took significant effort to extinguish the blaze. Let’s take a look at the project and see how this came to occur.

Grid-Scale Storage

The Victorian Big Battery is a grid storage project similar in construction to the Hornsdale Power Reserve in neighboring South Australia. However, where the Hornsdale facility fields 194 MWh of capacity and 150MW peak power delivery, the new project aims to go much further. The Victorian project aims to install 450 MWh of capacity and deliver a peak power output of 300 MW.

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Repair Hack Saves Tesla Owner From Massive Bill

July 16, 2021 by Dan Maloney 74 Comments

As expensive as a new car is, it almost seems like a loss leader now to get you locked into exorbitantly expensive repairs at the dealership’s service department. That’s the reason a lot of us still try to do as much of the maintenance and repairs on our cars as possible — it’s just too darn expensive to pay someone else to do it.

Case in point: this story about a hapless Tesla owner who faced a massive repair bill on his brand new car. [Donald]’s tale of woe began when he hit some road debris with his two-wheel-drive Model 3. The object hit penetrated the plastic shield over the front of the battery pack, striking a fitting in the low-pressure battery cooling plumbing. The plastic fitting cracked, causing a leak that obviously needed repair. The authorized Tesla service center gave him the bad news: that he needed a new battery pack, at a cost of $16,000. Through a series of oversights, [Donald]’s comprehensive insurance on the car had lapsed, so he was looking at funding the repair, approximately half the cost of a new Model 3, out of pocket.

Luckily, he got in touch with [Rich Benoit] of The Electrified Garage, one of the few independent garages doing Tesla repairs and customizations. The video below is queued up to the part where they actually do the repair, which is ridiculously simple. After cutting off the remains of the broken fitting with a utility knife, [Rich]’s tech was able to cut a thread in both the fitting and the battery pack, and attach them together with a brass nipple from the plumbing section of the local home store. The total bill for the repair was $700, which still seems steep to us, but a far cry from what it could have been.

Hats off to [Rich] and his crew for finding a cost-effective workaround for this issue. And if you think you’ve seen his EV repairs before, you’re right. Of course, some repairs are more successful than others.

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A Robot To Top Up Your Tesla

July 2, 2021 by Danie Conradie 37 Comments

The convenience of just plugging in your car in the evening and not going into a gas station is great as long as you remember to do the plugging. You really don’t want to get caught with an empty battery while you’re in a rush. [Pat Larson]’s Tesla plugging robot might be a handy insurance policy if you count forgetfulness among your weaknesses.

The robot consists of a standard Tesla charging plug attached to a 2-axis robotic arm mounted on [Pat]’s garage wall. Everything is controlled by a Python script running on Raspberry Pi 4. After taking a picture with a camera module, it uses a Tensor Flow Lite machine learning model to determine the position of a reflector on the charging port cover. The platform moves back and forth to align with the charging port, after which it opens the charging port using the Tesla API. It then extends the arm towards the charging port, using ultrasonic proximity sensors for distance control, and again uses the camera module and Tensor Flow to look for the illuminated Tesla logo adjacent to the charging port. The charge plug is flipped out using a large servo, and after some final position adjustment, it takes the plunge. While robot won’t be winning any interior design contests, it does the job well, and adds a bit of convenience and peace of mind.

Other Tesla hacks we’ve seen include building a working Model S for $6500, turning an old Honda into a speed demon using Tesla parts, and a Casio F-91W that can unlock your Tesla.

Flat Transformer Gives This PCB Tesla Coil Some Kick

June 9, 2021 by Dan Maloney 16 Comments

Arguably, the most tedious part of any Tesla coil build is winding the transformer. Getting that fine wire wound onto a suitable form, making everything neat, and making sure it’s electrically and mechanically sound can be tricky, and it’s a make-or-break proposition, both in terms of the function and the aesthetics of the final product. So this high-output printed circuit Tesla should take away some of that tedium and uncertainty.

Now, PCB coils are nothing new — we’ve seen plenty of examples used for everything from motors to speakers. We’ve even seen a few PCB Tesla coils, but as [Ray Ring] points out, these have mostly been lower-output coils that fail to bring the heat, as it were. His printed coil generates some pretty serious streamers — a foot long (30 cm) in some cases. The secondary of the coil has 6-mil traces spaced 6 mils apart, for a total of 240 turns. The primary is a single 240-mil trace on the other side of the board, and the whole thing is potted in a clear, two-part epoxy resin to prevent arcing. Driven by the non-resonant half-bridge driver living on the PCB below it, the coil can really pack a punch. A complete schematic and build info can be found in the link above, while the video below shows off just what it can do.

Honestly, for the amount of work the PCB coil saves, we’re tempted to give this a try. It might not have the classic good looks of a hand-wound coil, but it certainly gets the job done. Continue reading “Flat Transformer Gives This PCB Tesla Coil Some Kick” →

RC Car Gets Fan-Assisted Downforce To Slay Tesla’s 0-60 Times

May 23, 2021 by Lewin Day 26 Comments

Tesla have claimed that their upcoming new Roadster will post a sub-2 second 0-60mph time. While it’s backed up by little more than a shiny website at this stage, [Engineering After Hours] took the number as a target to beat with his RC fan car build. (Video, embedded below.)

We’ve seen an earlier prototype of this build before, with the first version generating enough downforce to successfully drive upside down. The new build has several modifications to maximise its lateral acceleration capabilities. The new build drives all four wheels, which are fitted with sticky tyres coated in traction compound for maximum grip. The main drive motor, along with the fan and skirt assemblies, are all mounted in the center of the car now to properly balance the aero loads across the axles and provide a stable weight distribution for fast launches.

The results are impressive, with the car posting a 0-60mph time of just 1.825 seconds. There’s likely still time left on the table, too, once the car can be tuned to launch harder off the line. We’d love to see a racing series of fan-equipped RC cars hit the track, too, given the amount of grip available with such hardware.

Continue reading “RC Car Gets Fan-Assisted Downforce To Slay Tesla’s 0-60 Times” →