Supercharging Only

[republic]

Howdy everyone. New here. I just confirmed my order and wanted to consult your advice - I couldn't find a similar thread by searching, so here we go.

I have no charging at my apartment or at work, 120V or otherwise. However, the Bethesda MD (and soon to be Woodbridge VA) SC is fairly close by. The only choice seems to be juicing up once or twice a week at the SC, preferably on early mornings so as not to inconvenience road trippers. My main concerns pertain to cold weather; there won't be much trouble in summertime.

1. What's a good percentage to charge to? If I charge to 75% each time, it shouldn't harm the battery, right?

2. How much charge will I lose during the winter? I heard it's 1+ mile per hour when it's cold outside, and Wh/mi doubles while driving. Even with just a 10-mile round trip commute, that sounds like I would expend 30+ rated miles per day. How cold does it need to be for this to occur? I'm afraid of bricking the car because one morning it's extra cold and I can't make it to the SC.

3. How much slower are SCs when it's cold outside? Should I expect to wait around for several hours each time? That would be a major hassle.

Only homeowners have access to home charging, so this may be the only way going forward. I bought the car to support progress, even though EVs are ridiculously impractical for renters. Any tips are greatly appreciated.

 

[JakeP]

This will become ridiculously inconvenient, very quickly. One of the biggest joys of owning a Tesla is having a full "tank" every morning, and never having to worry about "refilling" the tank, except on the road trips, when supercharger stops are acceptable time spent.

Highly recommend just installing a NEMA 14-50 plug at your apartment. Talk to the landlord about it again, if you haven't already. It's really not that expensive, depending on how close your parking spot is to the service box. And there may be incentives for him to install a charge station on the property.

 

[steve841]

Personally, I'd try to work out something with the apartment folks .... a NEMA 14/50 outlet couldnt be outrageously priced to install. I'd start there and offer to split the cost (in hopes of convincing them it's in their interest, if not, well offer to pay).

Making a trip to an SC just to charge seems rather cumbersome ... especially the day you get lazy and wait ... only to get a nasty cold wet day to have to run over to charge.

 

[republic]

Oh, I totally understand. A couple years ago, I rented someone's spare bedroom, and plugged my old Volt into a 120V socket by running a 100ft extension cord down the driveway and into the house. It was great to wake up with a full battery every morning.

My parking spot is several hundred feet away from the service box, and I'm afraid an installation would cost several thousand dollars, none of which would be recouped when I move again. Has someone here done a parking garage installation of this nature?

 

[Jaxcoffee]

I wonder if SolarCity could come up with a small compact setup that would produce enough power to cover situations like this?

What is the smallest possible panel needed to produce enough for charging?

Certainly would be interesting to explore.

 

[Cottonwood]

Oh, I totally understand. A couple years ago, I rented someone's spare bedroom, and plugged my old Volt into a 120V socket by running a 100ft extension cord down the driveway and into the house. It was great to wake up with a full battery every morning.

My parking spot is several hundred feet away from the service box, and I'm afraid an installation would cost several thousand dollars, none of which would be recouped when I move again. Has someone here done a parking garage installation of this nature?

2nd choice is work. They get the 30% income tax credit, also. Most employers are very supportive, brings good green karma... :wink:

 

[republic]

I'll look into that. There is a government parking garage with four level 2 chargers 8-10 minutes walk from my office. If only I can convince the fed public works guys...

 

[AmpedUP]

Amazingly, the notion of super charging all the time doesn't seem to be showing up as a problem for the battery. Rather, charging under any circumstances to a high state of charge when the battery is hot, or letting the state of charge go to nearly zero, seem to be the two outstanding issues affecting battery life. Thankfully, both are probably well managed via software on the MS. I agree with others that super charging only will simply be too big of a hassle. It will be like HAVING to go to a gas station every few days for 30 minutes or more. It's also a form of ICEing, in my opinion. Sure, Tesla won't bother you about using super chargers this way, but it's not the intended use.

 

[TexasEV]

2nd choice is work. They get the 30% income tax credit, also. Most employers are very supportive, brings good green karma... :wink:

Unfortunately this tax credit for installing alternative fuel vehicle refueling infrastructure expired at the end of 2013.

 

[paulkva]

Welcome and congrats on the order! A few thoughts:

1. Tesla claims that charging (or supercharging) regularly as high as 90% SOC is fine for the battery. There's plenty of debate on this site on that topic, but in general you're protected by the 8-year warranty. If you can't charge regularly (supercharging or otherwise), I expect you'd want to go to 90%. If you end up using 25-30 miles of range per day, you'd have to recharge about once per week.

2. I have a 10-mile round trip commute, and on a "bad" (really cold) day I use 20-25 miles of rated range to drive those 10 miles. That's Polar Vortex weather though, like 10F with snow/ice and HVAC running. Mere cold, e.g. 30s/40s/50s like the last couple days, I can get close to rated range (~300 Wh/mi) if I don't use the HVAC. I also lose charge throughout the day, but I don't think it has ever been more than 1/2 mile per hour, regardless of weather. (But I do park in garages at home and at work.)

3. You should never need to wait several hours while charging at a supercharger, regardless of weather. Yes, the charging rate tapers, especially above 80% SOC. But in theory you should be able to go from ~0% to 80% in ~40 minutes, and 80% to ~100% in another ~40 minutes. There are LOTS of posts about supercharging rates throughout this site. The bigger problem, at least in Bethesda, will be the potential need to wait for an available charger, although I have no perspective on how crowded it might be during off-hours.

Your best option is still to try working something out with your apartment or office; driving from DC to Montgomery Mall or Potomac Mills every week is a major hassle compared to plugging in at home or at work. For example, can you swap parking spaces with someone who's closer to the service box? But if you can't work something out, you might want to consider (a) the 85 kWh battery and (b) twin chargers, if you haven't already ordered them, so (a) you can go longer between recharging and (b) you can charge twice as fast at Tesla stores and service centers.

Other possibilities:

* To the extent they're convenient and available, you'll also want to scope out the various Level 2 charging options near your home and work. If there's some place you frequent (restaurant, gym, grocery store, mall, etc) with L2 charging close by, it could save you some of your trips to superchargers.
* Take a look at plugshare.com, not just for public chargers, but also for home chargers that people have offered to share. There are ~10 in the District and >20 inside the Beltway, and it might be worth your while to try working out an arrangement with one of them if any are convenient to you.
* Once Tesla starts selling the CHAdeMO adapter, you might want to buy one and look into eVgo (evgonetwork.com), as they have 2-3 Level 3 chargers inside the Beltway.

 

[deonb]

Welcome and congrats on the order! A few thoughts:

1. Tesla claims that charging (or supercharging) regularly as high as 90% SOC is fine for the battery. There's plenty of debate on this site on that topic, but in general you're protected by the 8-year warranty. If you can't charge regularly (supercharging or otherwise), I expect you'd want to go to 90%. If you end up using 25-30 miles of range per day, you'd have to recharge about once per week.

From Professor Jeff Dahn's comments on:
http://www.teslamotorsclub.com/show...ituation/page5?p=574103&viewfull=1#post574103

Also, does the rate of charge (0.5C vs. 1C vs 1.5C etc.) have any impact on the cell life?

YES - I WOULD AVOID CHARGING AT GREATER THAN C-RATE AND WOULD RECOMMEND C/2, ESPECIALLY FOR "ENERGY CELLS". POWER CELLS (E.G. IN TOOLS) WILL HAVE LITTLE PROBLEM WITH C-RATE CHARGING AND WOULD BE FINE. THE CELLS IN THE TESLA S ARE MORE AT THE ENERGY CELL END OF THE SPECTRUM.


C/2 on a Model S is 42.5kW. A SuperCharger charges at 1.5C.


I would seriously look for a primary charge source that is not a SuperCharger.

 

[republic]

Sikes. Looks like a level 2 charger is necessary. How quickly do MS's charge at public charging stations? My old Volt only did 10 mi/hr at Chargepoint stations, and that's way too low if I have to sit around waiting.

 

[deonb]

Sikes. Looks like a level 2 charger is necessary. How quickly do MS's charge at public charging stations? My old Volt only did 10 mi/hr at Chargepoint stations, and that's way too low if I have to sit around waiting.

Around 16 mi/hr at most of them. It's impractical to wait. You need to have a charger at either home or at work, or the ownership experience will be miserable.

If you don't want to move soon, how about just installing a 110V 20A (NEMA 5-20) outlet? Will be cheaper than the copper required for 40A, and even if the installation is $1000 it will be less than you'd pay for gas over a year.

 

[Cottonwood]

Don't forget the lowly 5-15, 3-prong outlet. Tesla says don't use an extension cord, but if you use a heavy duty #12 for 50' or #10 for 100', you are better than 90% of in-wall outlet wiring. A 5-15 only gives you 3 mph, but that is 30 miles in a 10 hour overnight charge and 75 miles in 24 hours. A 5-20 (20 Amp outlet) will give you 4 mph, 40 miles in 10 hours, and 100 miles in 24 hours. It all adds up and reduces the times you have to forage in the wild. :wink:

Good Luck!

 

[republic]

Thanks for the moral support, everyone. I'll solicit quotes for conduit installation. A 14-50 might run over $5,000 given the distance. We'll see - it's not impossible to pay for, given the recent behavior of TSLA stock.

 

[deonb]

Thanks for the moral support, everyone. I'll solicit quotes for conduit installation. A 14-50 might run over $5,000 given the distance. We'll see - it's not impossible to pay for, given the recent behavior of TSLA stock.

If this is a really long distance, also check for cost of installing a 6-50. You'll get the exact same performance as with a 14-50, but you can run 3 wires instead of 4.

 

[republic]

If this is a really long distance, also check for cost of installing a 6-50. You'll get the exact same performance as with a 14-50, but you can run 3 wires instead of 4.

That's a great idea. Are there any specs I need to tell the electrician, e.g. the amount of power draw? To have an HPWC, would I need twice the wire?

 

[TexasEV]

Unless you bought the dual charger option, which seems unlikely as you weren't planning on charging rapidly at home, there is no benefit to having a 100A circuit for the HPWC. You will need a 50A circuit whether you use a 14-50 outlet, a 6-50 outlet (that's the "50" in 14-50 and 6-50), or a HPWC. As HPWC has to be hard-wired and you're in a temporary location, that's probably not your best choice.

 

[landover]

Unless you bought the dual charger option, which seems unlikely as you weren't planning on charging rapidly at home, there is no benefit to having a 100A circuit for the HPWC. You will need a 50A circuit whether you use a 14-50 outlet, a 6-50 outlet (that's the "50" in 14-50 and 6-50), or a HPWC. As HPWC has to be hard-wired and you're in a temporary location, that's probably not your best choice.

Why do so many people use the 14-50 instead of the cheaper 6-50? The only resin I ask is because I just bought 65' of 6-3 wire last night at Lowes and I probably could have saved about 40 bucks or so.

Thats right the 14-50 comes with the car so no need to spend the extra money on the adaptor.

 

[brianman]

Why do so many people use the 14-50 instead of the cheaper 6-50? The only resin I ask is because I just bought 65' of 6-3 wire last night at Lowes and I probably could have saved about 40 bucks or so.

Thats right the 14-50 comes with the car so no need to spend the extra money on the adaptor.

RV parks tend to have these rather than 6-50. Other places do as well.

At the time I took delivery, you could choose a 6-50P or a 14-50P adapter but not both. If you wanted both, then you pay the money for the second adapter. I have no idea if the policy has changed since then, because I've only bought one car from Tesla.