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Servicing and repairing electric cars requires new skills (economist.com)
60 points by sohkamyung on Oct 25, 2021 | hide | past | favorite | 122 comments



Servicing and repairing electric cars is not going to be in demand as much as repairing ICE cars ever was. E.g. a lot of first generation Nissan Leafs are mostly still driving around on their first battery pack. Some of them have gotten life extensions with a battery pack replacement that is better than what they shipped with. They might still be doing shopping runs 20 years down the line. There is just very little that goes wrong with these things.

Most maintenance is basically going to be replacing tires, topping up some fluids (e.g. windscreen wipers), etc.

Battery replacements are sometimes needed of course but mostly not until well into 5 digit mileage. Quite a few manufacturers give you 8 years/100K miles warranty (whichever comes first) on the drive train. The reason is that they mostly only start failing long after that.

Of course any kind of serious work on an electrical drive train is going to need an electrical engineer. There are quite a few shops already specializing in salvaging electrical drive trains and repurposing them for ICE conversions of e.g. classical vehicles. Not an impossible skill to learn. But indeed very different from servicing the types of things that fail on ICE cars which have lots of moving parts and complex systems.


>> Most maintenance is basically going to be replacing tires, topping up some fluids

The only think that might be any different is the engine/fuel system. It still has a drivetrain. It has plenty of bearings, rods, suspension and brake elements that need exactly as much servicing as in any other vehicle. Go to any general mechanic shop (not a dedicated engine/trans facility). They are working on suspension. They are replacing broken broken glass/plastic bits and pieces. They are chasing electrical gremlins (intermittent faults). They are fixing fluid leaks. None of that is anything to do with the type of engine under the hood.


> brake elements that need exactly as much servicing

Brakes are generally used a lot less thanks to regenerative braking (kind of like trucks use eddy current brakes to lessen wear on mechanical parts: https://en.wikipedia.org/wiki/Eddy_current_brake https://www.klamretarder.com/en/retarders/truck-brakes-cfk ).

> They are fixing fluid leaks

There is also much less fluids circulating (some cars, not all, use liquid-cooled batteries and engines; add windshield wipers and that's about it). So less fluids to worry about.

There is just a few orders of magnitude less mechanical parts that can wear out and require servicing.

Suspension, tires and body work is still required, of course. There will probably be maintenance needs on auxiliary systems like the in-car entertainment system or headlights.

However, most of the maintenance work on regular cars is related to the combustion engine: timing belt changes, oil changes, gearbox issues, brakes, exhaust, differential, shaft, fuel pump, air, fuel and oil filters, spark plugs, starter, lead battery. A whole class of issues is avoided (timing belt failure, running without oil or coolant, inadequate fuel). Generally, control electronics should also be more integrated and prevent major (expensive) failures.


> There is just a few orders of magnitude less mechanical parts that can wear out and require servicing.

I don't think you realise what "orders of magnitude" means. There are very few things in an ICE car that "can wear out and require servicing" that aren't on the EV unless you count each nut, bolt and rod in an ICE car as a separate part that requires servicing.

The engine in an ICE is easily, cheaply and (relatively) quickly swapped out for one with all new parts, hence the engine is usually one single swappable part. Other than that, all the other components are going to be found on the EV too.


>There are very few things in an ICE car that "can wear out and require servicing" that aren't on the EV unless you count each nut, bolt and rod in an ICE car as a separate part that requires servicing.

On the contrary, the figure I'd heard is that electric vehicles have around 1,000 fewer parts than a fossil fuel based car. A quick search for references now I've found "Conventional powertrains may have as many as 2,000 moving parts ... while electric powertrains may have as few 20"[0] and "70% of an electric vehicle's component parts may be different from a gasoline-powered vehicle... The electric vehicle has one moving part, the motor, whereas the gasoline-powered vehicle has hundreds of moving parts"[1]. The relative simplicity of electric vehicles, with none of the sophisticated mechanisms for controlling regular explosions, e.g starter plug, fuel pump, fuel injector, air intake, radiator, oil pump, cam shafts, gears, pistons, fan belt, exhaust system, etc., is one of the major benefits from most people's perspective (although not admittedly from the perspective of a fossil fuel car mechanic).

[0] https://www.forbes.com/sites/jeffmcmahon/2019/05/30/more-ele...

[1] https://avt.inl.gov/sites/default/files/pdf/fsev/compare.pdf


> There are very few things in an ICE car that "can wear out and require servicing" that aren't on the EV unless you count each nut, bolt and rod in an ICE car as a separate part that requires servicing.

I would have put it the other way: if you count every nut and bolt, total count is likely to be similar on both ends.

If you only count relatively critical parts, though, I think you can easily reach 10-100x the number of mechanical parts that can fail on an ICE, unless you count the ICE as a single part (which it really isn't).

> The engine in an ICE is easily, cheaply and (relatively) quickly swapped out for one with all new parts

Last engine swap I had to look at (timing belt failure) was about 10k€, which I don't consider cheap at all (that's about half the vehicle value if you are lucky, and often isn't worth it). There is generally a lot that can go wrong on an engine and needs to be addressed individually, from piston/engine seals and resurfacing (expensive) to spark plugs (cheap) and clutch. Full engine swaps are usually your last ressort. And all of these parts playing nice together requires a lot of tuning, sometimes requiring some mechanical trimming here and there.

Granted, I am no professional mechanic (dunning-kruger applies), but some family members are, and I've often had to assist with complex repairs. The mechanical complexity of an internal combustion engine is really... nuts, and just lifting it out of the car usually requires a few hours of work, and a lot of plumbing.


I strongly disagree - full engine swaps are rare in ICEs and definitely not cheap, and most of the expensive servicing I've needed personally and seen in my community is directly related to the parts that EVs don't have at all - turbine issues hit you right in the wallet, gearbox/transmission issues, fuel pumps, etc. In comparison, the servicing needed for parts that are shared between ICE and EV - wheels, suspension, bodywork - is relatively cheap unless you need to repair collision damage.


> hence the engine is usually one single swappable part.

So if I need new spark plugs, I just swap out the engine?


Engine swaps are extraordinarily rare outside of custom cars. Swaps are far from simple affairs unless the car was designed to accommodate such custom work. But in reality ICEs are such a mature technology that engines now regularly outlast the rest of the car. Sure, external aspects sometimes need bits and pieces (fuel/coolant pumps, sensors etc) but the days of replacing cylinder heads or thrown rods are long gone. Even blown gaskets are almost not a thing anymore.


They meant engine swap using the same engine make/model. Swapping in a used or new one as a unit to replace the old one, without getting bogged down in details of engine internals.

That's not unusual at all, and is actually a rather easy task even DIY hobbyists take on at home.

I personally swapped out the motor on my turbo miata in a weekend after cracking a piston, using nothing but plain hand tools and some rachet straps thrown over a rafter as a hoist. The used low-mileage replacement was found locally for $250 and ran strong, bolted right in. The only fiddly bit was I had to drill and tap the oil return hole in the oil pan for the aftermarket turbo.

On another occasion I swapped an 05 motor into an 04 R1 for a friend, another small weekend project, didn't even get the floor wet. Modern ICEs are quite well contained, loosely coupled (though less so on exotics/superbikes with stressed member engines), consistently affixed (within generations) modules. Mass production kind of forces this outcome. You can swap them out easily.


"Interestingly" most problems with ICE are almost completely electronic. (Sensors, circuits, and the occasional electric motors.) Because the mechanical components are so well optimized "away".


> chasing electrical gremlins

Can't think in a better description for this. Thanks for this jewel.


Of course any kind of serious work on an electrical drive train is going to need an electrical engineer.

EE's are exceedingly rare in most blue collar industries that work on substantially more complex electrical systems than EV's. Most folks in this industry go to trade schools or are sponsored by a company to learn on the job. How this translates to Tesla's remains to be seen. AFAIK you have to take your Tesla back to the dealership for most things, certainly for any warranty work. I would expect at some point there to be a short class and certification that mechanics attend at Tesla. When Tesla is big enough I would expect that to evolve to some third party company that certifies mechanics. All of this assumes that Tesla continues to grow towards the size and scale of any of the current automobile manufacturers.


You are probably one of minority who enjoys having financial freedom to buy a new car and replace it after couple of years.

A lot of people just don't have finances and will be buying second hand cars and will generally try to extend the life of it for as long as it is possible.

A Tesla here in Poland costs as much as a small flat in a city center. Half of population does not have income to buy their own flat, let alone an electric car. That half of population currently buys cars that are are about 10 to 50 times cheaper because they have no value to people who have any possibility of buying a new car.

A Tesla might be more reliable for longer, but it will eventually reach that part of market.


>A Tesla here in Poland costs as much as a small flat in a city center.

Any links for those 200k flats in city centers?


> Any links for those 200k flats in city centers?

You could have done the homework yourself (seeing that your name is most likely Polish) but I will humor you anyway.

https://www.otodom.pl/pl/oferty/sprzedaz/mieszkanie/cala-pol...

There is a bunch of flats that are available at that price.

An example from first results page: 189k PLN, 2 rooms, 38 square meters (400 sq ft), Sosnowiec city (200k population) strict center: https://www.otodom.pl/pl/oferta/sosnowiec-centrum-dwa-pokoje...

This one site lists 12 THOUSAND current ads for flats for sale under 200k PLN but I assume significant portion is mislabeled or duplicate or not in a city center. There is no way to filter for city centers but there is half a dozen offers on first couple of pages.

Still, there is a lot of reasonable flats in that price range.

Of course you will have hard time finding anything large and forget about luxurious, but this is reality people with below average salaries live in.


"Cała Polska" here isn't "city centres" outside of few depressed cities like Sosnowiec. You can't seriously talk about cities and include ads for Gryfów Śląski.

If you look at actual cities, then you might find ruins, mislabels, 17m^2 "apartments" and tons of "Zapytaj o cenę".


> Most maintenance is basically going to be replacing tires, topping up some fluids (e.g. windscreen wipers), etc.

You don't know much about cars, do you? Other than oil changes, filters and plugs, what exactly do you think needs constant maintenance on an on internal combustion engine?

As far as reliability goes, in the cars I've owned (+300000km on a single car sometimes) none had needed ICE-specific repairs. The things that break the most in an ICE vehicle are still present on the EV (drivetrain problems, coolant system problems, electrical problems).

I want an EV too, but I am under no illusion that my maintenance work and repair work is going to drop significantly.

In fact, it might go up initially (new things to learn about the EV, for example the software/hardware diagnostic tools needed are probably different to what I am used to now).


My 200.000 km car had absolutely no defects related to the ICE, if something broke it was with the steering, suspension, air-conditioner, electric etc.

However, that was because the immense amount of preventive maintenance I did to keep the engine in its operating parameters:

- oil swap, fuel, oil and air filter change every 20.000km

- timing belt change every 80.000km, that involves changing all the related pulleys and an additional belt

- coolant refresh and preventive replacement of the coolant pump, to preempt a very nasty silent degradation by insuficient cooling

- cleanup of the exhaust gas recirculation valve and sensors, which tend to gunk up with modern diesels

- clutch-related maintenance (disk replacement and transmission fluid swap) that an equivalent electric (not a Tesla) car will not need

- mandatory emissions tests and checks - which I pay

So yes, the defects will still happen on electric cars, but you take away the bread and butter of any mechanic shop - maintenance of the ICE (and to a significant extent, brakes too).


> drivetrain problems, coolant system problems, electrical problems

This, and the suspension.


> Of course any kind of serious work on an electrical drive train is going to need an electrical engineer.

Why would this be so?

Removing and replacing parts shouldn't need the people who designed the parts to be present. Serious work on ICE drive train don't need mechanical engineers.


> They might still be doing shopping runs 20 years down the line.

Not in the northeast or midwest US. Here in the rust belt, the only cars that make it to voting age were either rarely driven, or never driven in the winter. The frame and suspension components literally rust away into nothing due to a high-salt diet here. You can replace the suspension components when they die (not cheap) but you can't do much about the frame. The underbody coatings that dealerships like to sell as an upcharge actually hasten the frame's demise.

ICE engineering has gotten amazingly good over the last few decades, to the point that engine failures under 150k miles are quite rare unless basic maintenance has been neglected. One auto shop owner I know of says he makes the majority of his money on brake jobs, tires, and suspension work. He says he would be just fine if all cars were switched to electric overnight.

So while it's undeniable that electric cars are more efficient and will eventually win out over ICE for all passenger vehicles, I'm not particularly convinced that they will be either easier to maintain or any longer than our current cars. Longevity can only be achieved by the manufacturers actually designing their frames and bodies to be at least moderately rust-proof, but of course they have several strong incentives not to do that.


Until brilliant engineers find novel ways to make the drivetrain so cheap it breaks down sooner.


you don’t need an EE for serious work. you just train people for specific jobs. swap a motherboard, swap a motor, repair a battery module. none of it is a big deal if manufacturers don’t act like apple and keep parts and schematics secret.


>Of course any kind of serious work on an electrical drive train is going to need an electrical engineer.

There's a certain bias here towards indiscriminate use of the title Engineer. The title, when combined with the prefix Electrical implies actual professional licensure by the State.

These are very skilled people, who I wouldn't let anywhere near an actual repair environment. You really want an electronics Technician, who actually knows how things work in the real world. Engineers quite often are "book smart", and as long as they are in their specialty, quite valuable folks. Left to their own devices, on the other hand, they tend to be surprised when things blow up because they didn't understand that red wires are positive. (I saw it happen)

Any new technology has new hazards. I can imagine that quite a few buildings were blown up or set ablaze when automobiles and gasoline fumes combined with open fires for heating. Over time, people figure it out.

Quite a few people have been dealing with the combination of high current and high voltage for decades, ham radio operators, the also had the hazard of high frequency RF which does odd things, and yet most of them survived. ;-)


> Servicing and repairing electric cars is not going to be in demand as much as repairing ICE cars ever was.

Let's test this theory with some data.

From 2016[1]:

"Last year, according to a Reuters analysis of data provided in the company’s annual report, Tesla spent $1,043 per vehicle on actual repairs and set aside $2,036 in warranty accruals to cover future repairs on the vehicles it sold in 2015. It trimmed warranty expenses by 17 percent from 2014 and cut warranty accruals by 34 percent.

Meanwhile, GM spent just $400 last year for every vehicle it sold on warranty repairs and set aside $332 for future work. Ford spent $429 per vehicle and set aside $308. Daimler spent $970 per vehicle and set aside $1,294."

Let's fast forward to 2020[2]:

" in 2020, GM accrued just over $3.4 billion and sold just over 6.8 million vehicles, so its accrual per vehicle was just under $500[...] in 2020, Tesla accrued only 1.3 times as much per vehicle as Ford, and only 2.5 as much as GM. It's still in third place, but remember, this metric is based on what a company believes will happen."

So Tesla is certainly setting aside more for warranty repairs than what would be needed for topping up fluids.

Now what could possibly require a repair in an EV, given that the drivetrain is so much simpler?

Here's Car and Driver's road test[3]:

"One of the pitches we hear often on the switch to EV ownership is that electric vehicles are cheaper to maintain. But, as we close in on 40,000 miles in a Tesla Model 3, the actual savings in service costs is turning out to be quite minimal."[3]

And loading the car up with complex electronics also creates repair pain points:

"Tesla has been ordered to recall roughly 159,000 vehicles to fix a problem in the Media Control Unit.[...] Many vehicle controls in a Tesla are accessed via touch screen, and the NHTSA (National Highway Traffic Safety Administration) began an investigation after over 500 complaints were filed about the issue.[...] Once its onboard NAND fails, the touch screen stops working, freezing the end-user out of climate controls and from using the rear backup camera. It also is said to impact “audible chimes related to ADAS, Autopilot, and turn signals.”[4]

[1]https://www.reuters.com/article/us-tesla-warranty/high-warra...

[2]https://www.warrantyweek.com/archive/ww20210218.html

[3]https://www.caranddriver.com/reviews/a30209598/2019-tesla-mo...

[4]https://www.extremetech.com/extreme/319170-tesla-ordered-to-...


The introduction of ECUs (electronic control unit) brought a lot of new problems to repair shops. And frankly many times they don't really know why something is or isn't working. In the end it often comes down to replace all parts in an error chain such as the sensors, cables and sometimes the complete ECU. It's just a different world for a classic mechanic.

Incidentally in a neighbour town a repair shop has popped up that has specialized in ECU repair. They developped a process to disassemble ECUs, dissolve the resin that contains the PCB and then do the repair on the boards.


Story time.

I had one car about five years ago - a 1982 VW Scirocco. A 1.7L engine powered by mechanical fuel injection, controlled by an early ECU.

It had a problem where the revs would bounce at idle like it had a big cam. Vroom VROOM vroom VROOM. Because of this, I got it very cheap.

I realized if I opened and closed the hood it would stop.

The ECU was mounted next to a hood hinge. Resoldering some connections for some capacitors fixed it. I ended up swapping in a modern turbo motor though. :)


In the US, OBD II was mandatory in 1996.

In that context, what's a classic mechanic?


OBD-II only requires the car be able to report faults related to emissions. You can (and many did) build cars without central computers and still provide OBD-II compliance. For a long time, even if there was an ECU it might only have been handling injection and ignition timing. The modern approach, where a car is essentially a computer with some mechatronic peripherals related to making the wheels turn, is relatively recent even now.


> only requires the car be able to report faults related to emissions

I'm just a layman who dabbles in diy car repair but from my experience with a cheap Chinese bluetooth obd-ii interface and an android app it reports far, far more than that. There's almost an obscene amount of data, and this was with an old car that was made only a few years after obd was released. I don't think this statement is correct.


The point is in "required". The makers can do the car report anything that they want, but older cars often report the bare minimum. If your car has android is modern. The difference between a car made before 2000 and a car from 2005 is huge.

Cars currently are really sophisticated computers with tires. There are a lot of systems all managed by the central ECU. Things like airbag, electric windows, seat heaters, electronic brakes, ABS, coolant circuit... each one are managed by its own circuit.

Not needing oil changes or air flow meters for the mix, electric cars will be much more simplified in some parts but I bet that are absolutely arcane in the other. And the battery can kill you easily.


> if your car has android is modern.

I think you misunderstood, I bought a cheap bluetooth obd2 device and accessed the data from an open source android app. It was a 2004 model from memory, the amount of data you could glean from that blew my mind back then.

Older and easily serviced cars are fun, most things you can do yourself with a service manual. For a few things like changing brake discs I got a mobile mechanic to come to my house to do it and teach me at the same time.

You don't need many tools to get started. Working on your own vehicle is a very self-reassuring hobby.


I stand corrected then. Thanks

I agree that the amount of info is incredible. The problem of the cheap diagnoses machines are that they aren't always updated. Not to mention the market flooded with pirated products that can made more harm than good. Many cars share the same error codes for very different things so interpretation is also a tricky issue. Translation in chinese machines is often of bad quality also.

Professional diagnose machines play in a different league and are really expensive.


No, it is entirely correct. Auto makers in Asia and Europe had engine-control computers such as some of the Bosch Jetronic family, and each manufacturer had a bespoke diagnostic interface -- many of which persisted long after OBD-II arrived. These automakers were relatively quick to tie their existing diagnostics tools into the OBD-II port (often speaking a different protocol along the same mechanical connection).

US auto makers were still running throttle-body fuel injection (no ECU required) or were licensing German ECUs (and not tying them into the OBD-II system). Almost all the US automakers were desigining OBD-II compliance with minimal integration into the rest of the engine as a misguided cost-saving measure. So for about a decade in the US if you plugged in an OBD-II reader, it would let you know if there was an emissions-control problem (bad O2 sensor, bad MAF sensor, etc) but be completely silent about other (often critical) engine problems. This situation was obviously stupid, but it took automakers a long time to change course.

Today, most so-called OBD-II dongles are actually microcontrollers which speak multiple marque-specific protocols, auto-negotiate which one to use on startup, and give you scads of information. But at its heart, OBD-II is an emissions-focused standard, which is why it's mandated by EPA regulation in the US and is one of the "measures to be taken against air pollution" specified by the EEC/EU.


So? A mechanic working 25 years ago had more than a little bit of incentive to understand electronic control systems. That's my point.

Is the idea that we should build cars so that dead people have an easy time servicing them?


I suspect the OP was making a historical analogy to the past experience of the ECU transition. The ECU transition was disruptive and caused pain for both mechanics (who had to reskill) and consumers (who had to deal with a market full of mechanics who didn’t necessarily know what they were doing for a long time.)


I think this is an overly abstracted view of how transitions work. In reality, most trades are experiential-apprenticeship businesses, and technology advances slowly. For example, a 15-year-old car may run ignition with a distributor, while a newer one may have coil packs that receive signals from MOSFETs in the engine computer assembly. Fixing those two systems can be totally different despite the fact that both have engine control computers.

Technological advance is not a step function and describing every transition as disruptive is not particularly meaningful even when it is true.


I haven't really seen mechanics reskill, what local shops seem to do is to employ separate "electronics people" as another specialization - like they already had bodywork handled by separate people who do all the bodywork and nothing else; so now they have "classic mechanics" working on the mechanical parts (which, frankly, is most of the work) and whenever OBD shows something nontrivial they hand it off to someone who does nothing else but debugging ECUs and sensor/wiring issues.


We could see OBD as the car equivalent to USB port in computers.

Classic cars from 40-70's don't have any way to be connected to an external computer (normally). Practically all modern cars (and none of the trucks) share the widespread OBD-II 16 pin connector. In the middle you can find a mess of different connectors in old cars from 80's and 90's when each brand was trying to produce their own unique plugs (You were forced to pay for their original software in the maker's official concessionaire). This was regulated later by laws to allow other companies entering in the market and for makers to reduce the mess.

Electric cars could experiment a similar opening process, or not.


Some cars with OBD 2 still require special connectors and software to fully explore the ECU. For example to properly connect to my Volvo you need a whole setup, to the point where an enterprising individual has made a business out of selling pre-installed software/hardware/laptop bundles: https://www.swedespeed.com/threads/vida-dedicated-laptops-fo...


> Classic cars from 40-70's don't have any way to be connected to an external computer (normally).

Allow me to blow your mind with the VW type 2 bus diagnostic port from my 1974 bus: http://www.speedyjim.net/htm/plug.htm

But yes, even that port was analog, and was dropped in later models.


shops have been equipped to deal with ecu equipped cars for decades. often it is even helpful, plug scan tool in, tells you which cylinder is lean or misfiring etc.


My mechanic is very old school; but he's not afraid of the battery in our (early) Honda Insight. Discussed it with him and I'm far more comfortable with cow cooking electrical potential than he is; but he's not afraid of it just knows there's some extra precautions to take. Nothing that they don't do when busting out the big welder already.

If I expected him to rebuild the battery pack with new cells; that'd be silly. I don't expect him to rebuild an automatic transmission, either. Not that he couldn't necessarily, but that kind of job is far better farmed out to a specialized shop that concentrates on it.


12 Volt electrical systems can turn your watch or wedding ring into a red hot cauterizing brand in milliseconds. There are new dangers in these high voltage systems, but with proper training anything can be repaired.

*Even captured alien ships, if anyone has one, and a budget, I'm game to help.


There are one or two spots in a conventional car where that can happen. One is at the + battery terminal, and one where the battery main connects to the starter. Everything else is fused. And that's why you always disconnect the battery ground cable first before working on anything electrical.


Yup agree with this completely. You'll see the issue of disassembling a battery pack, basically don't do it unless you know what you are doing.

I saw a Nissan Leaf get a battery back replacement at the dealer. The adjacent bays were closed off as well. When asked the reply was something about the high voltage has killed 1-2 techs and now Nissan mandates they close of the bays during a battery pack swap.


> these high voltage systems

12V is Extra-low voltage. High voltage is > 1000V (with specific risks due to electric arcing).

With 12V you can't get an electric shock, and the biggest risk is short-circuit (which is where you can get cauterizing metal pieces) and then the battery itself is the most sensible part (Lithium battery really don't like short-circuits): battery fire is a much bigger hazard than burns.

Also, the short-circuit risk already exists with lead battery (even if the amperage is lower).


Lead-acid batteries cannot sustain high amps for a long time, so they are less dangerous in that regard. I should also point out that electric drivetrains can be in excess of 400-800V to reduce amperage.

Any well-designed battery pack should have some kind of integrated short-circuit and temperature protection, though.


> Lead-acid batteries cannot sustain high amps for a long time, so they are less dangerous in that regard.

The specific hazard discussed above was about overheating a wedding ring or a watch. With 100 A, you'll reach that point in around 100ms. No need for long time at all, and a lead battery poses the exact same risk in that regard.


I know someone who had that exact experience on an ICE vehicle.


How is 12 volts high voltage? 12 volts would take a long time to heat up a ring or a watch, not millisseconds.


You are correct that 12 volts is not high voltage. However it can still heat up a ring or watch in milliseconds if the power supply can supply the needed amperage.

Using the equation V (volts) * I (Amps) = P (watts) we could calculate the power of putting a car battery through a ring: 12 volts * 100 amps[1] = 1200 watts. That's more than your average microwave.

The reason you don't heat up when you touch a car battery is that at 12 volts your skin (mostly an insulator) won't conduct the needed amps. Metal (a conductor) will however transfer close to the full 100 amps of the battery.

Here's an example of the effect[2]

[1]: https://www.bestpowerbattery.com/how-many-amps-is-a-car-batt...

[2]: https://www.youtube.com/watch?v=8Wx6-ysokJU


With 110/220V AC, you only need to touch the phase to be in trouble. With 12V, your body will basically block all current from flowing, so to get in trouble you'll need to accidentally make the metal part to connect both electrodes of the battery (short circuit). This is much, much less likely than with other low voltage system (btw, 12V is Extra-low voltage).


One of the elecrodes of the battery (-) is generally connected to the metal body. You only need a cable touching your ring while your hand rests on the frame to cause a short, which can happen. Or a loose cable touching the car frame.

It's generally immediately obvious, and can be remediated by pulling the cable away before it welds. But dropping a screwdriver in the wrong place can and will (statistically, thanks murphy) happen, so better use insulated screwdrivers and gloves, to reduce the likeliness of it happening.


> One of the elecrodes of the battery (-) is generally connected to the metal body. You only need a cable touching your ring while your hand rests on the frame to cause a short

The current won't flow through your hand, 12V is too low to pass your skin with a significant current. The only way the ring can have raise to a significant heat is if the ring itself touches both sides of the circuit (anode -> car frame -> ring -> wire -> cathode). Anode -> car frame -> hand -> ring -> wire -> cathode won't cause any short, because your hand acts as a big resistance in that circuit.


> current won't flow through your hand

Of course not, I didn't mean to imply that.

> if the ring itself touches [the car frame]

That's what I meant.

> 12V is too low to pass your skin with a significant current

Now of course the human body has a complex impedance, with cell membranes acting as capacitors: higher frequencies let more current flow. And that also depends on how much skin there is (single finger vs arm to foot), if it is wet, etc. I remember trying a (discharged) 9 V battery on my tongue as a kid... that was literally quite a shock, even with continuous current.

In the end, I wouldn't bet that an electrocution is impossible using a mere 12V of electric potential.


We weren't talking about electrocution here, but about heating a ring quickly enough to burn you, which requires a much higher amperage than what's needed to kill you.

Anyway, given that 12V is considered safety voltage for submerged swimming pool material in France, I'm pretty confident it is be extremely unlikely to kill anyone.


It's not high voltage, that's the point. I suggest looking for videos [1] on welding steel with a 12v car battery to see how fast metal can heat up with enough current behind it.

[1] eg. https://m.youtube.com/watch?v=2TtwrqIDnxg


Those are going to be mostly solid metal, so they're going to have very low resistance. Worst case scenario, you have a silver ring, which has the lowest resistance of any common metal at normal temperatures. Even at a high value of 0.1 ohms (it's sure to be much lower than that), you're looking at 1440 watts, around the heat produced by many plug-in heaters in the US.


It's the amps, not the volts.

A 12V car battery can supply hundreds of amps if you give it a low enough resistance to go through.


12V is high compared to a lot of <5V electronics that do "the thinking" for 12V & 24V power systems that do "the work" in a lot electric systems around the world.

As for the heating up... https://www.youtube.com/watch?v=nbGcSjRAyxs is a good demo of how fast 12V can heat up a small hunk of metal given enough amperage (in the case of that video 12V at 100A) . There are a surprising amount of 12V and 24V DC power systems (like in that video) can push in well over a kilowatt (12V at >100A or 24V at >50A) of power in a dead short situation.

My father had a paperweight in his shed that looked like someone used a spanner as a fork for lava, drooped away from its normal shape like a Salvador Dali clock, one end barely recognisable with blackened carbonisation marks and a ragged but lightly polished place where it was cut clean from something with an angle grinder. 24V at 150A for just a few seconds before the batteries were discharged, big marine batteries for lots of current to kick start an old heavy duty engine, lots of Amps but not many Amp Hours, still enough to destroy the spanner.


A similar problem: what happens when low margin fuel/petrol/gas station businesses start going insolvent? I wonder if states are ready for businesses to be abandoning their underground storage tank infrastructure in a decade or two?


Petrol/Gas stations make money from the convenience store, not the fuel. Considering how long batteries take to charge, they will make more money (but they would have to expand capacity significantly).


I think it all depends on the location of the service station. The big gas stations on major freeways will likely survive. But, the local neighborhood stations near suburbs or other housing will likely go away as folks charge where they park their cars while at home or work.

This article goes into data a bit based on information from Norway which has been electrifying passenger vehicles rapidly. Although, I wish there was better data to draw on. Maybe London will provide some data soon as they add more and more zones where EVs are preferred.

https://www.bloomberg.com/news/articles/2021-02-18/when-cars...


Petrol/Gas stations are the last place I'd want to spend time whilst my car is charging. My guess is supermarkets and shopping centres are going to fill that need and local petrol stations will disappear.


I'd love to see the emergence of Japanese style konbini convenience stores. Something with a better selection than the big gulp and roller dogs of your typical American pit stop. That might actually drive a trend where a 20 minute stop to fill up makes sense.

Shopping centers definitely have a nice synergy but I can see the demand for ev spots outpacing supply, so there will likely always be need for on demand charging.


they make operating cash flow from convenience store, the profit ultimately comes from increase in land valuation, same game as mcdonalds really


Globally, McDonald's makes an average of ~$200,000 income per store per year. Convenience stores mostly don't do that well, but the typical land isn't appreciating at anywhere near that pace either.

(It can be in some places; here, there's undeveloped land near most of the stores, which is a common scenario…)


Really? Gas stations usually become toxic waste cleanup sites at EOL. How do they turn a profit by selling the land?


Exactly the term the EPA uses is Brownfield:

> Petroleum brownfields, such as old abandoned gas stations, are being cleaned up and reused to the benefit of communities across the country. EPA’s Office of Underground Storage Tanks (OUST) and Office of Brownfields and Land Revitalization (OBLR) jointly focus on the cleanup and reuse of petroleum contaminated sites.

https://www.epa.gov/ust/petroleum-brownfields


Many gas stations are on valuable land, such as on the corner of two major streets.

So maybe whoever is redeveloping that land will be willing to pay the cleanup costs to gain access to it.


I predict the emergence of a cottage industry of rentable towable generators. Unfortunately you can't charge a Tesla while driving, but there have been EVs that let you do this. Regardless, I think there are certain situations (camping and long road trips) where having some electric peace of mind would be valuable, knowing you won't get stranded if you can't find a charger.

Also I suspect we will need underground tanks of dinosaur squeezings for longer than 20 years. Cars being sold today routinely last over 15 years, plus yard equipment, generators, etc.


They definitely aren’t ready. Zoning as it exists requires extensive environmental cleanup or delays of at least a decade before development can happen. A bunch of land is going to lay fallow for a good while.


I was skimming through the EPA’s Underground Storage Tank Responsible Parties documentation and getting more and more horrified at how I am sure these companies will structure themselves, via lease agreements or other mechanisms, to limit their liability as they go insolvent.

https://www.epa.gov/sites/default/files/2014-03/documents/rp...


Pretty sure that this is happening already- there are definitely fewer petrol stations than there were.


I've been watching Rich Rebuilds on Youtube. The channel has previously converted gas cars into electric cars and currently has a series about converting a Tesla into a gas car with a V8 engine.

https://www.youtube.com/c/RichRebuilds/videos


And he's extensively covered the repair skills needed when rebuilding his flood-damaged salvage title Tesla, including teardown repair of battery packs, various ECUs and other onboard computers. These are skills he's picked up himself, Tesla don't provide shop manuals or training to 'unauthorised' mechanics.


> Tesla don't provide shop manuals or training to 'unauthorised' mechanics.

They are basically big tech on wheels doing big tech things.


Take in mind that this would be absolutely illegal in Europe in 99% of the times, and a huge pain in the ass in the 1% remaining.

And when I say huge I mean huge. Months of bureaucracy. To start can't be done without the maker agreeing and certifying that the modification does not affect the safety of the car (and the maker would never agree, of course).

For a TV show? of course. Do it. Just don't expect to be allowed to drive that car in a public road. Ever.


Uhm, there is no way that a mechanic should ever try and rebuild a battery. Never.

There are multiple thousands of wires inside, and multiple hundreds of tap fuses. Every single bolt and joint is critical and needs just the correct amount of cleanliness and jointing compound applied.

The safety systems only work as well as the battery can isolate the problem (usually isolating the battery from the vehicle). Random workshops working on electric cars will just lead to internal battery problems that are uninterruptible by the control systems (ie a loose bolt or a washer floating in the casing), and this will lead to fires.

And after you’ve pulled it apart, what about the quality control on all the casing water seals? Especially the single application seals (gaskets don’t work well in practice)?

Battery aside, if you unbolt a motor resolver or move anything important then you need to do a resolver or phase calibration, which you can’t do without OE special equipment. Again, this could cause serious issues like hardware overcurrent and sudden cut outs, loss of power steering etc at high speed.

The days of mechanic shops servicing these vehicles is going to have to be over… there is no way it will ever be safe for someone to touch the power train without all the right OE specific equipment, the right checklists and several weeks of training for each vehicle.

Source: I was an EV battery design engineer.


It requires detailed training to build/rebuild an engine from scratch as well. Making sure the clearance tolerance for the bearings, valves, and a bunch of other critical stuff are correct. Accounting for how much the piston rod expands and contracts under load.(The rod will lengthen slightly at the top of the stroke.) Bolts for the bearing caps and cylinder head must tightened in a specific pattern and in iterative amounts of torque.

Get some of this wrong and the engine self destructs. In the worst case hot internal parts of the engine exit the engine and cause a fire.

Porsche had an issue where they used some bad bolts causing catastrophic engine failure and several vehicles to burn on their GT3 line.

https://www.motorauthority.com/news/1090959_porsche-fires-ev...

Basically, there are many components on cars that require specialist skills to get right every time.


Woah, that's wild. Is a screw-up that universally catastrophic across engines? My very, very naive understanding of cars is pushing me towards thinking that a homologation version of a GT3 car is sort of an extreme outlier, but I know very little about engines, and my intuition is almost certainly way off.


How often do cars get an engine rebuild by a local mechanic these days? When the timing chain failed in my Saturn, a new engine was more than the car was worth.


That's a good point; my VW GTI got one at a local shop under insurance a few years back. The turbocharger wasn't hooked up quite right the first time. It wasn't a severe issue - the engine was just noticeably less powerful. Luckily it was a quick fix and they were very good about rectifying the issue, but yeah, what you're saying checks out, even in the outlier cases where a fix is covered.

(Humorously, in a chain of weird luck, I also had a full rebuild of a regular Golf engine in the same five year span, but that one was done at the dealer.)


I’ve got an LS6 build in process right now. Lots of us do it on the regular.

It’s not that common with shitboxes, but even then it happens. We swapped my kids Honda Civic’s head about a year ago after a blown head gasket.


I've just finished rebuilding my BP4W race engine for my mazda. It seems like an annual event for me considering the amount of power I'm pushing through the poor thing.


No it is not universal think of all those beater cars you see on the road they don’t need the precision as a 300+ hp car. Just keep adding oil. Also people do things like valve adjustments because they can be out by a certain factor and still run just with decreased performance. Obviously you can have certain aspects of an engine that will later prove to be fatal but there are lots of engines that run like crap and get people from A to B just fine. I am not saying some precision isn’t needed but for a lot of applications it is somewhat forgiving.


Rare. More common in high-performance because they're pushing the limits.


Right, and in my experience they get it wrong more often than not on ICE cars, but the result is an engine with poor fuel economy that smells, knocks, throws a rod or runs roughly, not the whole car spontaneously catching fire and melting into a puddle.


> Especially the single application seal

Mechanics replace seals all day long. Heads are a far more extreme environment than a battery case.

> all the right OE specific equipment, the right checklists

This is the situation independent shops already are in for Audi, BMW, etc. They'll continue to do so if repairs end up being needed. What I doubt is the volume will be high enough to be worth the bother. If the battery needs rebuilding, they'll send it out to a third party like they do with starter motors or clutch linings. They'll continue to do alignments, tires, coolant changes, bearing swaps, etc. It's just the total pie is going to shrink and many places will need to close.


Dude, no. With your argumentation a mechanic should never replace a fuel pump in an ICE vehicle, or rebuild an engine, or rebuild a transmission, or replace airbags. There are speciality OE tools and training required for all of those jobs and guess what - mechanics are able to get those tools and the required training. The same as they will be able to get the tools and training for EVs. Its not rocket surgery, don't think you're working on some kind of crazy tech, its a battery and a motor. Source: electronics designer for steering systems


Very specialized things are normally outsourced to other mechanics. You can easily earn a life if you specialize in fixing car switchboards, specially when you are the only company in town that does it. Tools are expensive normally and earning the skills need a lot of self-training hours. As long as the spare part is expensive, too delicate or too risky there is a niche.


> The days of mechanic shops servicing these vehicles is going to have to be over…

What do you think they do instead? Throw the entire car away after a year? Obviously they get serviced by mechanics - don’t be silly.


Send them back to the manufacturer and have them repaired.


Who do you think repairs them at the manufacturer’s servicing workshop? Mechanics. Working in a shop.


I think, based on the argument, OP means "mechanic" and "shop" in the colloquial "non dealer/manufacturer-affiliated" sense.


What if there is no dealer (Tesla)?


Usually there are officially licensed contractors that provide repair services on behalf of the manufacturer. These contractors will have all the right equipment, materials and procedures.


This monopoly is going to have to be broken; we can't have an entire economy of motor vehicles run on Apple Shop repair pricing. This is already being seen around the John Deere DRM issue.


Saying that a battery array and an electric motor is more complicated than an internal combustion engine is laughable at best. After all that’s one of the big draws of switching to EVs: A simpler and by extension) more reliable propulsion system.


A battery typically has, excluding the rest of the EV:

    - Around 10-20 microcontrollers.
    - Between 150 and 250 voltage sensors
    - Between 150 and 250 tap fuses with fuse blow sensors
    - Between 5-10 contactors with sensing contacts
    - Around 50-100 temperature sensors
    - Around 300 to 500 N-fet switches with balance resistors
    - (Depending on the design).. up to 300 bus bars with perhaps 600 bolts.
    - In some instances, you'll find up to 50 pressure sensors
    - A variety of interlocks and plug sensors


Aren't most of these just arrays of identical parts, replicated for each cell (or, repeated for groups of cells).

How fault-tolerant are the battery packs? I assume, with all these fuses and sensors, it should be able to safely handle a wide range of internal failures.


The packs typically have near zero fault tolerance. If there is a fault with a single sensor, they will complain and go into a limp mode or refuse to function altogether. (This is because without a single sensor, it might be impossible to detect if the pack is about to catch fire).

Also each sensor is usually at the same potential as the cell that it's monitoring. So if there is a sensor fault, it could mean that it's unplugged or has come loose. Can you imagine the risk of a dangling 600V thing flying around inside the box?

For that reason though ... I'd need two hands to count how many technicians have accidentally shorted two cells in packs together by plugging the wrong sensor into the wrong place and shorting i.e. cell 32 to 42. When this happens, it will blow up a bunch of random surface mount fuses in the control boards, and other things all over the place. You need a lot of attention to detail to tear these things down.


People play with ev batteries to build gokarts, I think mechanics can be trained to do it


If secondary market teslas start bursting into flames it's going to hurt Tesla's reputation even if they swear up and down that it was an unlicensed shop every time. So they'd better start sharing repair manuals.


> The days of mechanic shops servicing these vehicles is going to have to be over

Explain to me again why I want to own one of these cars?


mechanics are already repairing battery packs with very grateful customers. thank goodness


The impact on garages is going to be one of the many knock-on effects as we uproot polluting infrastructure from the core of our economy.

A similar thing will for tradespeople electrifying houses with heat pump heating/cooling, hot water heaters, clothes driers, and induction stoves. Our economy is going to need to adapt incredibly quickly if we deploy at the necessary rate.


I guess there's a large variety of reasons why cars break down. Maybe I'm just lucky(?), but all the actually expensive problems I had with my car so far had very little to do with the fact that it's a hybrid car. Rust, puncture, broken tail light, broken rubber caps/washers, broken touch screen (left as-is). I'm sure that the mechanics who handled my car know not to touch the battery -- even if it's "just" ~200V vs. 800V. Both are very dangerous voltages.

(ICE cars require oil changes all the time so that's a major difference perhaps, but EVs still require some lubrication, right?)


unlikely I think, older gen cars used to have grease nipple for you to replenish old grease, newer car parts abolished those and instead you just throw the part away and replace. I'm sure some would say it's designed obsolescence but I think it's probably worth while for good portion of the cases as that grease nipple can introduce contaminants too...

the cynics in me thinks the hybrids and ev are still over engineered to convince the masses, once mass adoption began the electronics can build in design obsolescence much easier..


An interesting takeaway:

> All this could have a big impact on garages’ revenues. McKinsey, a consultancy, thinks evs may reduce spending on spare parts at American dealerships by as much as 40%. With no oil to change or spark plugs to replace, income from routine servicing will also be lower. Porsche’s Taycan, for one, is reckoned to need 30% less maintenance than if it was an ice vehicle.


There’s a subtext to this article, that cars are getting better at diagnosing themselves and the troubleshooting typical for older and ICE cars is required less and less. It’s not fair to say that an average mechanic wouldn’t be able to service new cars, but rather that new mechanics will be unable to repair anything but new cars who have their problems diagnosed with a computer.


I recently read that more than 70% of the code in modern ECU's is for diagnostics.


And a big part of the remaining is for calculating the correct combustible/air mix


I always imagined that was just a big table with the accelerator on one axis and revolutions on the other.


Much more complicated in fact. Your car measures constantly the air flow, the temperature of this air, the altitude over the sea level, the velocity of the car, the position in real time of the accelerator and clutch pedals, etc... and then the computer takes all and sends an order to inject in the motor exactly the amount of combustible required for this parameters. Then manages the opening or closing of the valves to allow the gasses go out and those are reintroduced in the motor to be burnt twice. The remain is send then to the anti particles filter and the good parts are allowed to go out, while the problematic ones are sealed in a box.


mechanics will be unable to repair anything but new cars who have their problems diagnosed with a computer.

This has been a thing for at least 10 years now, started by the luxury brands. There really wasn't much troubleshooting required for ICE (despite your mechanic's insistence on the severity of the issue) until cars starting running more LoC than a Mac. Pre-2005 ICE was very simple compared to any modern system, ICE or E.


James and Kate disagree: https://youtube.com/user/James0852

James shows how a pro services EV cars on his channel.

Here is the upgrade of a Nissan Leaf: https://youtu.be/bY66PGpR7jk



I for one look forward to training my FSD to hypermile effectively.

https://en.wikipedia.org/wiki/Hypermiling


Maybe all those years racing electric r/c cars will serve me well.




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