So, is my Model S 'happy' when connected to public chargers?

So, is my Model S 'happy' when connected to public chargers?

I believe the manual says 'a connected TMS is a happy TMS'. Never did read the manual, sorry.

Problem is, I only charge at work, for free. Using the public charger. For a maximum of 3 hours every weekday.
When I do need to charge at home, I use the Fremont supercharger since I live close by, and once a week, early in the morning on weekends. No rush, no fuss, not many wanting to supercharge at those times.

So, is my TMS 'happy' under these conditions? Sure, I can connect once in a while at home, but its a hassle!

pebell | 13 septembre 2013

So are you asking whether the TM can feel the difference between "public electrons" vs "homegrown electrons"? ;)

pebell | 13 septembre 2013

My guess is, yes, the TM will definitely be the happiest when charged using your own solar panels!

mrspaghetti | 13 septembre 2013

Well, you're not doing anything that will void the battery warranty. But can you explain why it's a hassle to plug in at home? I'd think it would be a heck of a lot more convenient than driving to a supercharger. However close it is to your house, it's not as close as your own wall outlet.

SunCoulombs | 13 septembre 2013

I think it's just a hassle if your garage is not well organized. Cleanup works wonders sometimes! ;)

earlyretirement | 13 septembre 2013

I think it would only be a hassle to charge at home if you are only on the normal non HPWC plug in. You only get 4 MPH charge! But if you have a HPWC and dual charger you get 60 MPH charge. So quick and convenient.

I think locals driving to their SC's for the most part don't put a value on their time. I don't know about you but it doesn't get much more efficient and easy than just charging in my garage. My time I'd kill driving to the super chargers would be much more than the electricity bill charging my car.

petero | 13 septembre 2013

Mrsphagetti, early. We obviously don't get it. "Free is Free!" IMO, Redshift's MS is not necessarily happy or sad - Redshift is happy when he is plugged in to free charging.

redacted | 13 septembre 2013

For the critics, keep in mind (1) redshift may be competing for garage space with a spouse or large dog or a spouse's car, (2) unlimbering the UMC to plug in again and (3) unplugging something from the only outlet in the garage. Some situations such as renting might also preclude making changes to the power structure of the house, too. So I can see how it could be a problem.

I'd feel insecure if I wasn't plugged in though. To my HPWC. Aaaah.

SunCoulombs | 13 septembre 2013

Wouldn't it be a sacrilege to own a MS but not enough power outlets and space in your garage? Such things should be arranged before the purchase.

Prasad B | 13 septembre 2013

From what I have read and heard some time back, Supercharger charging over time degrades the battery compared to regular charging - this is because Supercharger does a DC-to-DC energy transfer vs. the regular AC-to-DC energy transfer to the battery. This is irrespective of whether you fully charge your battery to 100% or the usual 90% (or around 230 miles range). I vaguely remember hearing this on one of Musks's conference calls, but need to verify.

mrrjm | 13 septembre 2013

Any electric car should always be plugged in when note driven. So that is when it is the happiest. I think this is in the owners manual.

tes-s | 13 septembre 2013

Sounds good to me. I only plug in at home when I drop below 100, or if I am doing something that needs more range.

petero | 13 septembre 2013

I am willing to wager that Redshift has a phone charger at his office too. Kidding aside, I put a high premium on my time and rather than spend an hour + or- at a supercharger every few days I choose to plug in at night. There is a line between being fiscally responsible and being cheap. I think bragging about being parsimonious crosses it.

AmpedRealtor | 13 septembre 2013

@ Prasad B - I'm not an EE, but I believe the battery normally functions using DC current. So feeding a DC charge straight into the battery is only bypassing an AC-to-DC conversion cycle, nothing more. The battery system is more than capable of handling the high current of the supercharger. It's not the rate of charge that negatively impacts battery life, it's the number of charge cycles as well as whether you are keeping your battery at extreme ends of its range for extended periods of time.

@ RedShift - Don't take my word for this, but I believe the biggest benefit of keeping the Model S plugged in when not being used is so that it can actively maintain the battery temperature within its ideal range. I probably would not leave it unplugged for extended periods of time if you live in very cold or very hot climates. I would not even think of not keeping my baby unplugged when at home here in Arizona. Thermal maintenance of the battery is very important. Of course it's a different chemistry, but the Leaf's battery here in Arizona is dying a premature death (capacity reduced by 50%) due to the high desert temps and lack of active battery cooling by the Leaf.

Also keep in mind that while the battery warranty covers failure, it does not cover degradation. Hypothetically, if not plugging in causes you to lose 25% of your battery capacity over 100,000 miles versus someone who does plug-in and only loses 15% of their pack over the same period of time, neither of you will be able to get relief under the battery warranty because neither of those degradations are covered. It's just that yours may be more if your car is subjected to temperature extremes without being plugged in.

SunCoulombs | 13 septembre 2013

One should not forget that SC's intended as a bridging solution and not as a regular charger, that's for sure.

MandL | 13 septembre 2013

Keep in mind there are many of us who live in urban areas and don't have a garage. I have a one car parking pad at my house. When there are no available spaces on the street, my husband can park at the curb cut and block in the Model S. That makes us luckier than most of our neighbors who have to fight for a space on the street regardless (and are so far nice enough not to block our space), but we're never going to be buying a second electric car unless one of us has convenient, reasonably priced charging at work.

This goes back to the fantasy of electrics taking over the world. Until and unless there is some kind of massive infrastructure upgrade, very few of the people who don't own their own parking space adjacent to their own domicile are going to be buying electric cars. Think of all those row houses and apartments in all the cities you've ever been in. The people that live in them for the most part will have an ICE car if they have one at all.

RedShift | 13 septembre 2013


I am just getting back at PG&E for making me switch to EV 9 rate in Aprill, and it was way more expensive with my home charging regime.
Then, my client installed 12 new free chargers at work. So, cool, this free thing is addictive, however small the savings are!

So every weekend, I go to play nd work out, close to e supercharger, just by coincidence. Cool, I have one more free outlet.

I was just ordering if TMS battery is conditioned he same way ('happy') when charging from J1772 and supercharges.

RedShift | 13 septembre 2013

Wondering, not ordering. Damn contact lenses, I m new to them and they are making my vision blurry.

tes-s | 13 septembre 2013

@ampedrealtor - is the number of charge cycles an important factor in battery degradation/life?

If one drives 40 miles a day, then plugging in every fourth day instead of every day would reduce charge cycles by 75%.

AmpedRealtor | 13 septembre 2013

@ tes-s,

I only know what I read, but I would suggest you check out this thread for some ideas and explanations:

More frequent and smaller charge cycles are supposedly better than longer, deeper cycles. You would have a longer, deeper charge cycle if you charged every four days due to the vampire drain. Again, just speculating.

tes-s | 13 septembre 2013

Thanks! That was interesting.

With all the input, I think I will plug in every two or three days and keep range between 100 miles and 235 miles.

That seems like a reasonable compromise between all the things (including convenience!) to ensure reasonable battery life.

The caveat is my car is in a garage that is always between 40 and 90 degrees - and usually in the 50 to 75 degree range, so maintaining battery temperature is not a concern.

Brian H | 14 septembre 2013

Your confusion is terminol(ogical) ;). A charge cycle always refers to a complete charge, or the equivalent in smaller charges added together. 10X 8 kWh is the same as 1X 80 kWh. No matter if the little ones get used up one at a time or not.