March 8th, 2019 by Dr. Maximilian Holland
On Wednesday night time, the eagerly anticipated Tesla Supercharger Version three (V3) know-how was unveiled, permitting the Model 3 Lengthy Range to receive peak charging energy of 250 kW! That’s properly beyond the facility levels anticipated by seasoned Tesla tech analysts (myself included). What does this all imply? Let’s dive in and talk about this new Supercharger know-how.
On this article I need to define some initial evaluation of V3 and talk about a number of the implications. I’m going to look individually in a coming article at what it means in sensible terms for charging occasions on street trips and the like. Briefly — Tesla is clearly giving us EV know-how that smooths away residual friction for fossil-driving people considering whether or not or to not make the leap to an electrifying transportation life.
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Estimated Charging Curve
Let’s dive in first with some modeling of what the charging curve of the Mannequin 3 Lengthy Vary on Supercharger V3 may seem like (and examine it with the maximum cost power recorded on Supercharger V2):
Permit me first to notice that I’ve referred to as this an estimated charging curve, and referred to as the current Supercharger parameters “Beta.” There are a few causes for this: Tesla’s blog article about V3 makes it clear that the corporate considers the current hardware and software program settings to be a public beta, and it is trying to “review and assess” the early outcomes earlier than rolling out extra hardware and probably tweaking the software program and parameters next month. The opposite purpose for sticking on labels of “Beta” and “Estimated” are that the announced (and 3rd get together documented) Supercharger V3 parameters have come as an enormous shock to me and different Tesla hardware geeks. One well-known and highly regarded Tesla group geek and detective (whose identify we’ll gracefully not speculate on) stated to me “how is that possible?” Personally, I was predicting peak charging on Mannequin three of not rather more than 160 kW, and “never” more than 175 kW! I’m going to have to stay some small print on my Tesla hardware predictions any more. ?
The charge curve I’ve modeled above is predicated on what we know thus far:
- Maximum peak energy is 250 kW on the Mannequin 3 Lengthy Vary.
- This corresponds to a peak of “up to” 1000 miles added per hour charging.
- 5 minutes of (candy spot) charging provides up to “75 miles” of “peak efficiency” vary (probably EPA city vary), which is barely less than gained from 5 mins @ 250 kW and the “1000” price (above).
- Thus, we will deduce that 250 kW is a short peak lasting a bit of beneath 5 minutes.
- Videos (together with 3rd celebration videos) recommend 250 kW peak power starts someplace before 10% state of charge, and sub-5 minute period factors to probably taper starting not a lot past 20%.
- Movies present that the Model 3 display estimates charging from low levels to 80% still takes round “27 minutes” and to 90% takes “35 minutes.”
- Thus, we all know that after the brief peak, there’s nonetheless vital energy taper at larger states of cost.
The curve is an honest fit to all of those parameters (I’ve run the numbers in geek-level detail on the spreadsheet that generated this curve). Clearly, this curve (as well as Tesla’s above factoids) specify peak performance (“up to”) underneath very best circumstances. You’ll not often hit all circumstances in the actual world for completely optimal charging — however should you do, the end result might be something like this curve.
Nevertheless, as I famous above, Tesla might anyway tweak the parameters it has to date specified, based mostly on results of the Beta testing. There are also various delicate variants of the above curve that would give a similarly close fit to the parameters. I should add that charging from the standard 10% start line to a high of 80% can take slightly below 25 minutes — considerably quicker than on V2 (around 33–35 minutes). Observe that the utmost recorded cost power values on V2, as indicated in the orange dotted curve, come from the info gathering and analysis of our buddies over at A Higher Route Planner (ABRP).
As a ultimate observe on the curve form, apart from the unprecedented energy ranges, the profile traits (especially the very early peak) do have precedent in a Tesla. Take a look at the cost profile of the older Model S 70 kWh battery pack (again from ABRP knowledge gathering):
What Does It All Imply?
Designing an early excessive peak of the charging energy is a brilliant technique by Tesla for numerous causes. Most importantly, it’s the most secure means of charging shortly whilst defending the battery — the facility nonetheless tapers steeply again to properly established energy levels after 50% state of cost, to stop over-stressing the batteries.
We know the Model three Lengthy Vary battery pack is sweet for 330 kW of peak energy output, so 250 kW (for a short interval of beneath 5 minutes) is inside cause. Tesla by now has in depth knowledge and information concerning the performance of those batteries over long durations and numerous circumstances and use instances. The early peak power is more environment friendly since, on a given cost session, a great proportion of householders will typically need solely a given quantity of further vary to complete their journey — and not have to recharge all the best way to 70% or 80% (or more), when 40 or 50% may be adequate.
Front-loading charging energy and added vary on this means is more environment friendly general than delivering the height power at 60–80% state of cost as many other EVs do. This occurs mainly as a result of most non-Tesla EVs spend nearly all of the charging cycle at power levels which might be in truth restricted by the utmost present (amps) of the charging hardware, and the pack voltage — which cannot be adjusted post-hoc — is progressively climbing throughout the cost session. Recharging a battery is by definition lifting its voltage again to maximum potential distinction (volts). As a consequence, on a charger whose present is maxed out for a lot of the charging session, the peak energy is necessarily someplace within the second half of that session, when the voltage is closing in on its peak. Newer and more powerful public chargers are enhancing this by shifting to much larger levels of current (amps) delivery, as much as 500 amps in many instances. This will likely permit some EVs to vary the form of the charging curve. Tesla designs both the automobiles and the chargers, so can have a more coordinated strategy to this optimisation process than another EV maker can.
Amp It Up!
Whilst we’re on the subject, this query of present (amps) is the primary purpose for surprise concerning the Supercharger V3. Let me explain. The Model 3’s battery pack has a nominal voltage of round 355 volts. Nominal battery voltage is often somewhere near the midpoint of full charged voltage (high) and absolutely depleted voltage (low). For lithium-ion chemistry cells, this typically varies between roughly four.2 volts when full and roughly 3.zero volts when discharged, with a nominal worth around 3.6–3.7 volts (i.e., the complete voltage range is roughly 15–20% above or under the nominal worth). For the Tesla Model three’s general pack with 355 volts nominal, this means that when charge is depleted, the pack voltage is likely round 300 volts, and when full, round 410 volts.
If that is right, then the 250 kW of peak power is delivered to an almost empty pack whose voltage is likely someplace within the range of 310–320 volts. Since watts is a perform of volts * amps, to realize 250 kW at ~315 volts, the peak present needs to be someplace near 800 amps, which is unprecedented for EV charging! Geek forecasters have been underneath the impression (on the idea of strong evidence) that the Mannequin three had hardware limits of around 525 amps. Something approaching 800 amps (even for a really brief peak) was properly past any expectation. Keep in mind that the designed-to-be-futureproof CCS 2.zero charging specification (that the Mannequin three in Europe is suitable with) presently faucets out at 500 amps. 800 is an enormous number and an enormous shock.
The Supercharger V3 hardware is reportedly additionally able to delivering up to 500 volts (although doubtless not concurrently with 800 amps). This bodes properly for future Tesla EVs which will increase pack-nominal voltages up by 20% or so. For those who’re curious about the potential for Tesla raising pack voltages, I mentioned this in one other current article taking a look at Supercharger V3 (a lot of which now appears hopelessly low-ball, given what has transpired)! The Audi e-tron and Jaguar I-PACE have nominal pack voltages of round 425 volts.
What else can we are saying about this elevated peak power? In V3, peak power is assured because the system design provides devoted energy to each stall, not kilowatts susceptible to being shared (and decreased) by the back-end energy cupboards having to do double obligation across two stalls. The Model 3 may also have a pack-preconditioning function that may try and get the pack near the perfect temperature for high-power charging when the car is aware of you’re heading for a Supercharging session. This enables the pack to receive larger energy levels than would otherwise be smart (for pack well being and longevity).
Tesla has stated it expects the typical Supercharger session period to be lowered by round half. This leads us to another purpose why early peak power is a brilliant strategy by Tesla. The expectation of halving average charging period isn’t because the typical charging power has doubled over the complete charging session (it is just double for the first 20% to 30% or so, then regularly approaches the V2 charging regime, and is not much totally different from V2 from 50% state of charge and above). No, the prediction of average charge period being halved is as a result of, in contrast to on V2, early peak power means substantial enough range for an honest onward drive can now be gained in 15 minutes (and then obtained once more in one other 15 minute break at your subsequent relaxation stop). On V3, staying for much longer is definitely not the fastest charging strategy for drivers, in comparison with getting back on the street taking another brief break again later. How a lot vary is added in 15 minutes? If the above curve is roughly right, when ranging from 10%, the Mannequin three Lengthy Range can add slightly over 54% of battery charge in 15 minutes underneath prime circumstances. 54% interprets to 176 miles of vary round city (EPA metropolis score) and even on the highway 54% is close to 160 miles of range (EPA freeway score) in respectable driving circumstances.
Entrance-loading the peak power is subsequently not solely better for the pack and for trip planning effectivity, however it should also encourage people to maneuver on comparatively shortly. In any case, the tastiest juice is within the first 15 minutes or so. Much past that and chances are you’ll as properly get going and have another fast rest break in 2 to three hours. For people to be joyful to maneuver on shortly obviously allows rather more use out of each Supercharger, serving many more clients. Smart and environment friendly.
The Supercharger V3 is greater than many people anticipated. With big present (amps) functionality and a great evolution of voltage, I’m frankly actually impressed by it. The facility ranges that Tesla has managed to push the Mannequin three Long Vary to are even more shocking. We don’t but know what energy the other Mannequin three pack sizes can be capable of charging at, however there’s each purpose to anticipate they’ll a minimum of regain equal percentages of their complete pack power for comparable charging period, if not the same absolute quantities of power as the Long Vary pack. We also don’t yet know the facility ranges the S and X will probably be pushed to on Supercharger V3 (the limitation is evidently not in the V3 charging hardware, but could be within the S and X battery packs).
Personally, I’m optimistic that the 100 kWh battery packs will see a much elevated cost price on V3 (I’ve mentioned this previously), although maybe not quite as dramatic a rise as the Mannequin 3 sees. Given current events outpacing some of my earlier predictions about V3, I’m not going to make any extra forecasts both approach right now. Let’s see what more we will study. Little question, Tesla will discover a option to shock us again.
In case you spot anything right here that doesn’t add up, or you’ve got some thought-about thoughts about all of this, please bounce into the feedback.
Concerning the Writer
Dr. Maximilian Holland Max is an anthropologist, social theorist and worldwide political economist, making an attempt to ask questions and encourage crucial enthusiastic about social and environmental justice, sustainability and the human condition. He has lived and worked in Europe and Asia, and is presently based mostly in Barcelona.
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