I mentioned previously about an acquaintance on another forum posting about his new Tesla 3. Another poster asked for details about charging and the mentioned among other things '950 kmh' which prompted said acquaintance to post another comprehensive answer. Here's how the conservation went:
'Yes, I DID mean 950 kmh!! It was NOT in any way a typo.It’s a very common way to express it actually, not weird at all!! Here’s how it works: Many people don’t really understand kW, or how much range they’re getting whilst plugged in. On the Tesla’s screen, I can display battery as a percentage full, and rate of charge in kW, and yes, that really does mean very little to many people. On the other hand, I can (and usually do) select the battery range, and charge screen rate of charge, in kilometres and kmh. Eg: with the PHEV, I could charge it at home at 1.8kW .... (which equates to about 8kmh or so.) So plug it in for an hour, and gain around 8-9km of range. (Five hours was a full battery.) With the Tesla I could charge at home at (user selectable) up to 32 amps, 3 phase IF I had 3 phase power, (11kW) which we don’t. ..... However I can also charge with single phase at up to 32 amps, which is around 7kW and around 45kmh rate of charge. I actually normally charge after midnight at a little under 10 amps which gives me around 14 kmh charge rate, (and FWIW that’s also what I’d get on any 10 amp socket.) Even my darling wife finds that VERY EASY to understand, but if I tell her it’s charging at 2.2kW, or perhaps say 7kW she’d look at me with a very quizzical face indeed! And yes, if I pull in to one of the latest high power DC chargers with a low state of charge battery, I can see initially up to 950 kmh rate of charge until it’s over 60% full, when it will start to taper off (and that’s close to 150kW if you really want to know. ;-) So, in summary, rate of charge in kmh is often the most common way that most people use to measure it on a daily basis. That then takes both rate of charge in kW and the car’s actual efficiency into account. (The model 3 is more efficient than almost everything else.)
'I did a few searches before your explanation but found no reference to an actual kmh definition … is it a Telsa’ism … Lol'
'Yes it is to a large degree, again shows how far ahead they are, but lots of people when discussing EV’s actually use it when talking about it, even if they don’t own a Tesla and can’t actually display it on their car’s screen. When you do a roadside stop to add range, it’s the only thing which really defines how long your actual stop will be.From the other manufacturers- I agree, most of them don’t use it very much at all as :1. they’re often embarrassed by it, and 2. Their smart tech can’t calculate such things accurately (and 3. they’re all in a big panic trying to catch up to Tesla.) Undoubtedly some of the others are better at the moment assembling cars with consistent panels gaps etc., and should be as they’ve mostly been doing it for many generations, but they’re typically miles behind on the battery, drive train, efficiency and technical side of things, and especially including long term battery management. For example Nissan Leaf and our PHEV were pretty hopeless in that regard, with bad battery management and degradation. The PHEV BMS for example uses just a fixed mathematical algorithm degrading the battery which takes no account whatsoever of the battery’s true condition, or how it’s been used. At least it had battery cooling- whereas even the very latest Leaf doesn’t, and suffers terribly in hot climates.As a member of a few electric vehicle groups, (incl Tesla owners club of Australia), a long time fan of EV’s (and having listened to for example, over 600 episodes of the podcast “EVnews daily”, plus heaps more other stuff), and having now owned two electric vehicles (one of course a plug in hybrid, ie: the PHEV), and having driven the Model 3, the Model S, the Model X, the Hyundai Kona EV, the Jaguar iPace, and the Nissan Leaf, - in that order of distance covered, I’m fairly sure that I’m qualified and “up to speed” on electric cars in general. Put simply, most non long term EV owners don’t really understand charge rates at kW other than to know that 150kW is much faster than 50kW, which is also much better than 2kW. In fact, you would be amazed how many people don’t even understand the difference between kW and kWh!So there are the TWO displays I can have on the car charge display on the centre screen. Let’s say that you have “x” kilometres available in the battery at the moment and need to do a drive of “y” kilometres, and are charging the car to make it a comfortable trip without the oft quoted (but very much exaggerated) “range anxiety”. Kmh rate of charge works a treat, and is very easy for the novice to understand, and also takes into account the car’s efficiency. (For example a Tesla Model 3 charging at the same kW as an Audi eTron is in fact charging at a much higher kmh speed, as it’s much more efficient in how it then uses that stored battery power.) The actual Tesla predictions on battery range are way better than all the others, without exception, and even take into account elevation change for a given route once you actually program in a destination and a route. For example we drove around two hundred and thirty kilometres the other day- after starting with 375 km in the battery (around 75% SoC), so the prediction was therefore that I’d get home again with 150 kilometres available. The actual figure: 143 kilometres when I pulled in to the garage. I did take a few very small detours and do a few extra stops. I wasn’t driving carefully, nor being proactive to get the best range, and could very easily have done better by driving more efficiently and/or slower.If for some reason when you’re on a trip it’s looking tight, (you can monitor it all on the graphical display, actual vs predicted), you just slow down a little to get on the right side of the graph. Thus there is effectively no “range anxiety”. The car will also tell me if I’m going to need to charge somewhere, AND even suggest a location, .... and it’s actually amazing how many lower powered chargers incl Tesla “destination” chargers are available. I also use the excellent “plugshare” app on the phone which will show pretty much everything including even the likes of 10 amp, 15amp and 3 phase plugs available at Showgrounds etc.Anyway, here attached are the two options, kW and battery percentage vs kilometres per hour and kilometres range.In the first, I’m charging at 2kW, the battery is at 76%, I have selected 9A rate of charge out of an available 12 on that circuit/charger combination, (and I have added less than 1kWh since charging stated. I’d just plugged in.)In the second, same 9A current selected going in to the battery, I’m charging at 11 kmh, I currently have 376km in the battery, (and have added 0km since charging started - again, it has just been plugged in.) The 11kmh figure also takes into account whether or not A/C etc is runnng- (which it was at very low power. ie: Turning it off would have added a little to the charge “speed”, probably up to about 14 kmh.)In both I have set the charge to finish at about 80%, the white line. As with all lithium batteries, you don’t typically charge to 100% unless you really need to.Guess which is easiest to understand for most people ;-) though it is extremely easy to switch between the two, and takes just a second or two. The other manufacturers WISH they could do this, but either can’t, or won’t as it shows up the weakness in both their software algorithms and also their lack of efficiency'.
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Michael.
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