I found the difference in 120V charge rate to be negligible in the cold. However, driving when the battery is cold uses significant energy to warm up the battery. 120V charging could not support my 16 mile round-trip commute this winter in northern Virginia. No problems commuting (and more) using 120V once the weather warmed up, requires some planning ahead at times though.
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I found the difference in 120V charge rate to be negligible in the cold. However, driving when the battery is cold uses significant energy to warm up the battery. 120V charging could not support my 16 mile round-trip commute this winter in northern Virginia. No problems commuting (and more) using 120V once the weather warmed up, requires some planning ahead at times though.
Look at the tesla web page under model s -> charging -> charge calculators.
40 miles of charge -
110v / 12a - 12hr 16min, $2.12, 17.7kWh
240v / 40a - 1hr 21min, $1.58, 13.2kWh
240v / 80a - 40min, $1.58, 13.2kWh
Polly Wog
Member
thanks all for your replies so far. beeeerock - I *know* your answer is the right onejust curious to hear what kind of daily mileage 120V-only MS owners can practically live with (assuming such people exist)
and yes, we cooked on an electric hotplate in our laundry room for a few months when we did a major kitchen reno. Took forever to boil water. I had forgotten about that, we survived but it was pretty annoying at the time!
other good points, Gizmotoy - I had not thought to factor in some buffer like you say in calculating; also, dsm363 haven't really thought about longer trips yet but good point...
@f-stop, I live in a condo and was stuck with 120V charging at home for my first 6 months of ownership, before I could upgrade to 240V. As others have said, it is doable - but will get tedious and annoying as time passes. One factor you haven't necessarily taken into account is that after you start driving your Model S, you will want to drive it all the time! I think you might want to start researching what it will take for you to get 240V up and going - there is a ton of great advice on this forum for doing it.
wcalvin
Member
Because of condo delays in installing the 240 V line (which turned out to be 207 v, which drops to 194 v at 40 amps), I got lots of experience with 120 v and extension cords over two years. You can top up about 30 miles worth overnight. If your commute is 40 miles RT, it still works if you can fill up during the weekend. You can do weekend road trips if there is a supercharger along the way or a DC quickcharge with Chademo.
When the 207v was finally installed, it didn't change life much. It just guaranteed that I could start out in the morning with a full tank even if I arrived "on fumes" the night before. Now I only have to plan the road trips and, if you've ever been a pilot, that's no worse than preparing a cross-country flight plan.
When the 207v was finally installed, it didn't change life much. It just guaranteed that I could start out in the morning with a full tank even if I arrived "on fumes" the night before. Now I only have to plan the road trips and, if you've ever been a pilot, that's no worse than preparing a cross-country flight plan.
@Max and also @KidDoc, thanks for your specific examples and comments - I'd guess my typical mileage is similar to yours, so thanks for the feedback. Mostly my original question is a bit of a thought experiment, I would certainly aim to install a 240V circuit (I already have 1 quote but need to get some others). In the meantime just seeing if it's reasonable to make-do with 120V if low mileage mainly local driving.
I may do a 2nd test drive (been offered a chance for an overnight test drive) - so maybe that would be a good firsthand test...
I'm kinda secretly hoping that to be the case if I buy a Tesla
Thanks for the feedback. "Doable but soon-annoying" seems to be the general concensus so far. And yes, I have been thinking about that - it's easy to imagine I'd want to drive it all the time!
Hmm..perhaps there is more to it when there are 7000+ cells in a full pack and regulated in modules. Admittedly, the biggest packs I made were 96V. So I agree, it may not in fact be the most efficient rate to charge. Some rules just don't scale from smaller format packs due to increase resistence. Good point to bring up.
I'm not sure I agree that 40-80A is best. Why not 30A for example?
None, the less, I stand by no real damage to the cells if charging at lower rate.
in my lease up in NY it's a house that was built in 1920 and has four 20A FUSED circuits in the electrical box. All of the receptacles in the house are 5-15 despite the 20A fuses. Up there I charge exclusively using a quick220 to convert two 120V curcuits into a 240V circuit and I charge at 12A. I use the NEMA 5-15 adapter attached to a custom adapter to 6-20 to the quick220. the quick 220 has two 5-15 plugs coming out of it into two different legs in the house. So this gives me 240v at 12A and charges at 8mph. Because it's a shared circuit with other utilities in the house, I don't use the 5-20 adapter (aka I don't charge at 16A). I've already popped a fuse twice using charging at just 12A (usually when the wife forgets to unplug the car and turns on the microwave or toaster while its charging).
40 miles of charge @ supercharger = 10mins, and free.
So? The user stated the Model S was DESIGNED to charge at 40A-80A. I asked for a design doc showing that. What you're showing me are charging inefficiency. I could say the car was "designed" to be supercharged, but that doesn't make it true.
I did it just for grins when I first got the car. I had a dryer outlet, but that required me to unplug it and leave the door to the garage ajar, so I mostly charged from a 110 circuit in my garage. My average daily commute is about 55 miles and I tended to lose about 10 miles of range net per day on 110. I could normally just let my battery get a bit lower every day and then make it up on the weekend. I think I went about 3 weeks like that until I was satisfied that it was viable for me. I didn't really even find it all that inconvenient, although once I did cheat and plug into the dryer when I had driven extra during the week and wasn't sure if I would have to take a trip Friday after work.
Gizmotoy
Active Member
Does that meet code? I've looked at a number of houses, and found that the garage outlets here are almost universally on 20A breakers but only have 5-15 outlets. Could I just swap the outlet and pull the extra 4A? Or do I have to check the wiring gauge as well? It's a measly 4A difference (12A->16A), but it makes a pretty large difference in charge rates (3mi/h to 5 or 6mi/h).
Gizmotoy
Active Member
Interesting. I've used maybe a dozen different 120V outlets and have never seen 4mph @ 15A, but have seen 6mph on 20A circuits occasionally (but 5mph more frequently). I guess I'll have Tesla check my UMC when I'm in next. I doubt every outlet I've used is degraded. Even 4mph to 5mph is huge, though. That's an additional 10 miles overnight.
Anyway, that's a big tangent from the question I posed, unfortunately.
4mph @ 12A, you mean (15A outlet)? I used to charge at 120V overnight for 2 months before I got my 14-50 installed. I had... 115V @12A IIRC, always 4mph (I'm sure I have a screenshot somewhere...). I charged at the inlaws with a heavy gauge extension cord and the UMC, also 4mph (@12A on a 15A outlet). The "regular" extension cords, dropped it to about 2mph charging.
Gizmotoy
Active Member
Yes. Was referring to outlet ratings. 15A and 20A are the two styles.
Searched around the forum. Looks like if the location is warm enough you can get up to 3.5mi/h on a 15A circuit according to Cosmacelf and others. Since we only get whole numbers you were probably getting 3.5 and the display rounded up, whereas mine was slightly below and probably rounded down. Presumably that's what's happened. I've never seen 4, but I wouldn't be surprised to find Bay Area power isn't the greatest.
No, I was getting 4mph (maybe 3.9 or 4.1 or...? but definitely not 3.5mph).
On a few occasions I was tight on miles so I did the math using 4mph, and calculate how many hours I'd be plugged in, and when I'd wake up and get the car the next morning, I'd usually be either spot on or within maybe 1 rated mile (12-14 hours with a difference of 0.5mph (4.0mph vs. 3.5mph) should be 6-7RM difference, that would be 1-2 hours of extra charging, I'd notice if I was missing that much)
I never did the math at my inlaws, so maybe I was getting 3.5mph there, I wont argue with that (even if the app showed 4).
I could have higher voltage than you, also. My 14-50 gets me 31mph, not 29mph as most people say they get.
I asked in another thread and Flasher told me that if the breaker was already 20A, then the wire should have been to spec and I was free to replace individual outlets. I think you just have to be careful that you don't have much other load on the circuit.
Yes it does meet code. I honestly don't know why, but many electricians like saving the $1 or so per outlet and only put in 5-15 receptacles rather than 5-20 receptacles, even though they installed 20A wiring and a 20A breaker. It's maybe a $5 difference if it is a GFCI. It is true that there are very, very few devices in the world that have an actual 5-20 plug, but the Tesla adapter is one of them.
It bears repeating that you get much more than just a 33% boost going from 5-15 to 5-20 (12A to 16A) since the car uses a fair bit of power to run the computers and cooling system for the batteries while charging. It works out to an approx. 42% increase in charge going into the battery.
Also, to compute true charge rates in MPH, you really have to charge for, like, 10 hours and calculate it that way. the Tesla display isn't accurate enough at those small numbers due to rounding errors.
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Cyclone
Cyclonic Member ((.oO))
Indeed it is. 4 months into ownership with a 40 mile daily commute and I still charge at 120v/12a. It works, but is annoying at times when unplanned things happen and I'm "on fumes". That said, it hasn't been that big of a problem since we have 200v/30a at work and a Supercharger down the street from work.
Zarwin
Member
The Tesla NEMA 5-20 adapter is my most useful destination charging adapter. I've used it at three hotels and one rental house. As others have stated, its a significant increase in charge rate off of a 120v outlet. What many may not realize is how common that outlet is becoming, especially oudoors. The house we rent for a week every summer had the outdoor outlets all upgraded to 5-20 last year, which made a huge difference when charging.
This is a 5-20 outlet at the rental house, which most people would just see as a normal outlet.
And this is the 5-20 plug, which probably a lot of people would look at and not realize that it will plug into the outlet above.
This is a 5-20 outlet at the rental house, which most people would just see as a normal outlet.
And this is the 5-20 plug, which probably a lot of people would look at and not realize that it will plug into the outlet above.
aha I've seen those outlets before but didn't understand what they were until now. unfortunately the only existing circuit in my garage is on a 15A breaker and outlet is a 5-15. (aside: what gauge wire is needed for 20A circuit vs 15A? Since my garage is unfinished inside, I can see all the wire runs... )
Anyhow thanks for the info and pics, this is useful for future reference...
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