Recharging on the road supposed to be via a to be built “Megacharger Network” that somehow is to be solar powered? Someone help me out here. How big are these batteries? How much draw will it take to charge one to 80% in 30 minutes?
And one assumes that the longer term vision is to have the drag coefficient further improved upon by having these run as virtual trains with V2V and use of autonomous features, possibly with no driver at all in future iterations and likely just one for the whole train sooner than that. That however means a train of them wanting to charge all at the same time. Roughly calculating this out I think that comes to 2.3K shitloads of power all at once.
Or does a fleet operation run these old Pony Express style, each grouping running half an hour behind the one ahead, with now rested (charged for a half hour) Semis waiting at each Megacharger station?
I give credit to the Tesla team (and I think that means more than just Musk) for making no small plans … but boy it is a leap of faith for any fleet or owner operator to go with this until Tesla proves the ability to deliver at least on the 3 and has some Megachargers built on the routes used already.
And if nothing else this gives the media something else Tesla to talk about than their production woes.
To be fair, we have this issue, too, at least, I experienced it when I had my Fusion Energi. I happened to have a lucky three-week spurt where the ICE never engaged once. One Saturday morning, the car was dead and I had to charge the 12V battery. Without the 12V, the high-voltage contactor won’t engage, and thus there’s nothing to charge the battery. What I don’t understand, though, is why the 12V doesn’t charge from the HV battery? Apparently it only charges when the ICE is running.
This could have been a bug affecting my unit only, but I’d read about the issue on other forums from other Energi drivers.
it’s got to be a bug somewhere, e.g. a module didn’t sleep and drained the battery. We have a Fusion Energi in my lab right now and I checked, when you turn the car on (w/o ICE running) the HV system lifts the 12V system to 13.5 volts. IIRC the '13-14 C-Max had some software issues causing 12V system run-down, don’t know if the Fusion was affected too.
ICE can have the “computer left running unexpectedly” problem too.
A couple months ago I left a Bluetooth OBD dongle plugged into my switched-off ICE car overnight. Which apparently kept at least some of the computers on, although the instrument panel was dead dark when I left the car with the keys in hand. Next day was a dead battery. Let it jump-charge for a few minutes and haven’t had a repeat.
jz, most EVs have a large parasitic draw from their various computers. Yeah, they should all be sleeping, but features like remote start, remote firmware update, detecting the remote control when the owner approaches all require you to energize some of the electronics. Sloppy optimization on your power states can easily suck a ton of power - apparently Tesla sucked about 80 watts.
So what you just observed in the lab is consistent with what others experienced. The HV system only lifted the battery to 13.5 with the car on. If the battery were left at 13.5, or the HV system were to engage a bypass circuit or something, you could directly power the electronics with HV derived energy only*. Assuming an efficient DC to DC converter and good firmware that will hard kill all the electronics* if the HV state of charge ever gets too low, this would work.
*by opening a relay and having a startup circuit that can only start again if a charging plug is inserted into the charging port and supplying power.
*some lead acid battery chemistries don’t do well with being kept at 13.5 all the time. The SLA in UPS batteries seem to do fine, and I think most EVs and hybrids use an SLA, however.
Ya know, I’m kind of surprised more hybrid/PHEV/all electric cars aren’t running supercaps instead of a lead acid 12v for this sort of thing. I suspect the answer is cost as it almost always is but supercaps offer a lot of advantages over stock car batteries. These Maxwell supercaps are what we use on some of our gensets and they’re the bomb.
80 watts is criminal. our standard for key off current draw is on the order of 0.01 amps.
except Balthisar was asking if the HV system kept the 12V battery charged only if the ICE is running, which is not the case. keep in mind this car has no alternator or any other belt-driven accessories.
Well someone did the calculations to come up something slightly precise than my 2.3K shitloads of power. Still roughing it though.
Actually not as bad as I thought considering they already have Supercharger stations able to charge 40 cars at a time. That’s three of these charging at a time and for a while three at a time would likely be plenty. I’d also be surprised if they did not have a system in place to reserve the spots on the route at precise times and to have the vehicles controlled to hit them precisely as they are available.
The module is the EV transmission. If there are limited service stations and parts are not available then the car goes nowhere. I don’t share your confidence in Tesla. When I buy a car it’s important that I can get it serviced if needed. It’s not a small matter to me. Stuff breaks and my daily driver needs to be reliable and that means it has to be repaired in a timely manner.
Now if I was ultra wealthy and it was another toy in my collection then the new
sportster would be the ultimate driving machine and I mean the ULTIMATE driving machine. I’d drop $250,000 on it right now. It’s a bargain at that price, and any potential warts be damned. I’d sign the Tesla fanboy registry without hesitation.
But this discussion is about the Model 3. A car that’s a day late and a dollar of quality control short.
It is a 40 stall Supercharging station the purpose of which is to recharge the vehicles on the road in the shortest time possible. I guess they could have built it such that not all could be used at the same time, or if all plugged in would decrease the rate by some percent but I think it is reasonable to presume that all 40 can be used as advertised as Superchargers at the same time.
I don’t doubt one can build a 40-connection Supercharger facility. I wonder how much challenge (AKA dollars) it will be for the local utility to drag that much continuous duty power capacity to wherever such a station is built.
As an example, the Florida Turnpike is a very limited access highway that runs the spine of Florida. When not passing through a big city, exits are 50-ish miles apart and service plazas with food and gasoline are about 100 miles apart. Pretty much every service plaza is in the middle of nowhere.
The advantage of being in the middle of nowhere and having wholesale access to batteries for storage and also to solar at wholesale (owning that company too), of course is that you can put up a whole bunch of solar and store it for use as needed, including at night.
Clearly they’d still use grid too (might even have a deal to sell some daytime power to them if it exceeds their demand and storage), but I do believe Musk that the vision is to have on site solar provide the bulk of the power demanded. The local utility will likely not be asked to provide much more than they would for any other truck stop.
I am rapidly becoming less skeptical. Convoys of these vehicles traveling V2V communication enabled tight, eventually completely autonomously, powered to no insignificant degree by solar produced and stored on site at Megacharger stops … yeah, that makes sense and interstate cross country hauling is easier for an autonomous system than dealing with meatbag drivers on city routes. This more than the Tesla 3 may be the killer app.
Well, you’d be wrong. Supercharger stations have racks of charger modules, and it takes a certain number of those modules working in parallel to charge a single car at the maximum rate. There are not 40*(# modules required for max) in most or all supercharger stations. My evidence for this is unfortunately anecdotal, but there is a clear connection between arriving first to a supercharger station and the reported charging rate on the car’s dash. (the algorithm they use doesn’t split as more cars arrive, it instead makes latecomers charge slower)
Also, you don’t necessarily get the max. It depends on the battery temperature, state of charge, and other factors. Finally, I think Magiver was saying over an entire thread that until superchargers are common as gas stations, we won’t see EVs?
Well, he’s totally wrong. There’s a lifetime limit on supercharging because it destroys the battery, and the Tesla software limits you. Basically, you cannot own a Tesla and charge it exclusively through supercharging if you don’t want the speeds to be throttled after a certain point.
Thanks for checking. I’m pretty sure the Fusion was 2017. Most of what I read online from others was for the C-Max, so it could be the C-Max having an issue, the C-Max being more popular, or C-Max people being more vocal.
I chalk it up to growing pains, but if it happens to a real customer, I worry about their impression.
Yeah, that agrees with what I read. It means that experienced Tesla operators are going to choose to park anywhere but next to another Tesla. Amusingly, the same algorithm people use when boarding a public city bus - only when every pair of seats has 1 occupant do people start sitting next to strangers.
