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Anyone have Model S charging information?

I did a search on Tesla Model S charging white papers and all I came up with was press release related information on Tesla's Superchargers.

My Zero has an on board 1kw charger that charges the battery at 1/9C (9kw battery). It accepts 110 or 220V via a standard (high current) IEC printer type power cord. The 2013 models will also accept a CHAdeMO high speed charger. The Zero's battery is around 65V fully charged so the charger is a simple rectifier (AC to DC) regulator combination. The Model S seems to have a lot more going on.

I ordered my S with two on board 10kw chargers. There seems to be a few cord options (wall chargers) and the Supercharger route. Can someone shed some light on what happens between 110V, 220V and Superchargers and the battery with the Model S? My assumption is that all batteries have the same fully charged voltage and that capacity is determined by the number of cell sets in parallel. So, some of my questions would be-

The Model S comes with a Mobile Connector. Is this a simple direct cord from my wall outlet to the plug under the brake light lens?
I ordered the twin chargers which I assume takes the car from having one 10kw charger to two of them on board. Is this correct?
What is the High Power Wall Connector? I ask because $1200 would indicate it is something more than a simple cable from the wall to the car.
Is the connector under the brake lens the only charging connector on the car or does the Supercharger use a different connector?
Does the Supercharger supply high voltage current limited DC directly to the battery bypassing the on board chargers (be they one or two)?
What is the battery voltage of a fully charged battery?
Is the Supercharger supply under the direct supervision and direction of an on board battery management system?

Thanks for helping to fill in these gaps for me

"The Supercharger concept for cross country travel probably relies on charging in the constant current realm for maximum bang for the minute."


Based on information I received from Tesla I believe the charging curve is much more involved and depends on sophisticated two-way communication between the Supercharger and the battery. Here is what Tesla provided in answer to a question I had:

"They start slow, ramp up, then ramp back down. The shape of the power curve depends on the current battery state of charge, ambient heat, battery heat, and a variety of other factors. Only a Model S and a Tesla Supercharger have this level of communication."


If all there is at a charging location is a NEMA 10-30 plug, and all I have is a NEMA 14-50 plug on my Tesla cord, is there an adaptor I can buy to make the NEMA 10-30 plug work for me?

@edavis008 - there will be an adapter available for purchase from Tesla, but it isn't available yet. You can make an adapter for 10-30, but it is complicated by the fact that there is no ground connection (which the car requires), though the neutral connector is bonded to ground at the panel. If you know what you are doing, some have made an adapter that routes ground on a 14-50 receptacle to neutral on the 10-30 plug (labelled as ungrounded and for Tesla use only), and then tell the car to only draw 24A instead of the 40A it expects because there is a 14-50 adapter on the cable.

@jat - Thanks. I don't know what I'm doing, and I would only need this occasionally, so it's probably not worth it for me to learn how to route the ground on a 14-50 receptacle to neutral on the 10-30 plug unless it's really easy. Is it really easy?

@edavis008 - it is easy, but I would hesitate to suggest you do it - it only takes a small mistake for serious consequences when dealing with electrical wiring.

Okay. What if there is a NEMA 14-30 charging location available and I have a NEMA 14-50 plug for my Tesla. Is there an "off the shelf" adaptor that will work for that application. Many thanks.

@edavis008 - I don't know of an off-the-shelf adapter, since something plugged into the 14-50 could expect to draw 50A. However, there will be a 30A breaker on the line so there is some safety there, and the 14-30 is a grounded outlet. So, if you had one, you could program the car to draw just 24A and you would be fine. makes custom adapters, and you might get them to build a 14-30P to 14-50R adapter for you if you tell them how it will be used. You might even get a 10-30P adapter as well.

@edavis008 - one other point -- the 14-50 differs from the 14-30 plug only in the shape of the neutral connector (the one opposite from the rounded ground pin). I haven't tried it and don't know if there would be other ramifications, but you might be able to simply cut off the neutral pin on the Tesla adapter and plug it into a 14-30 outlet (still telling the car to only draw 24A). Of course, if there is an issue, then you are without a working 14-50 adapter.

That's what these guys do to make a plug which can be used with 14-30, 14-50, or 14-60 receptacles in conjunction with an upgraded LEAF EVSE:

I made my own 14-30p to 14-50r. Simple enough, but cost c. $50 in parts. Could have done it cheaper but wanted it to look good.

Looks like someone makes an adaptor for a male L14-30 to a female 14-50R. That's what I would need, right? It's only $21 on Ebay.

edavis, I made one myself and the cost for the one you are showing seems to good to be true. It looks as though it would be like what I made but I would be concerned about the quality of the parts used. If it were $30.00 that would be about what I would expect.

And as others have stated you need to make sure to limit current on the dash otherwise you will trip the breaker. But it does work.

The parts I got for mine were $11 (shipped) for the 14-50 outlet, $16-20/ea for the 10-30 and 14-30 dryer plugs at Sears, and a few bucks for the metallic box and faceplate at Home Depot. So, $21 seems a bit cheap, but not unreasonable if they bought the components in bulk.

However, L14-30 is not the same as 14-30 -- it is locking pins rather than straight pins.

jat, I bought all my stuff at Home Depot. I used a 14-50 box and outlet combo (box looks like an arched doorway) along with some 6 ga. wire (18 inches). Probably overkill on the 6 ga. but that was almost the most expensive part. I had originally made it for my Roadster as I knew places that I had the 14-30 available but not the 14-50. I have not had any issues with it since I made it.

Thanks jat and Theresa for the great input. I think I'll make my own adaptors. We have to find a charge any way we can until the supercharging stations get built. I'm in Texas, where we don't have any yet.

I wonder if I can use the 50amp and 30 amp outlets that my motorhome uses?

Fun engineering stuff...I posted my reverse engineering and charging/range reference charts at (see sheet named 'BatteryPack')

I based analysis on the cell that says is in the pack (Panasonic NCR18650A). It shows charge/discharge curves, cycle life, etc. My guesstimate was that the batt pack is made up of series-stacks of 95-100 cells, with 70-74 of those stacks in parallel. That would put the required DC voltage for a full charge between 399 and 420 volts.

Remember: voltage is sum of cells in series. Current is single cell current times number of parallel stacks. Voltage is needed to drive motor RPM. Current is needed to create torque. Power is just voltage*current, so our 310 kW P85 corresponds to about 775 amps at 400 volts! Think of it another way: the battery-to-motor path has to handle over 3x the current of the powersource-to-battery path (unless, somehow, the batteries are reconfigured when not charging to provide a much higher voltage to the motor than the 400V or so from the charger)!

My simple input to the original question(s):

* HPWC hardly makes sense at home...mostly you're charging overnight, so NEMA 14-50 should do the trick. If you're on a road trip, the HPWC will hardly do you any good! If you have a "full battery commute" and are home less than 8 hours it is time to change jobs!

* supercharger is 90kW (DC)...a bunch more than the HPWC, which handles around 20kW (240Vx80A)

* car has a couple of 10kW rectifier/charger units on board and enough smarts to load-share or bypass them if you plug in DC supply

* biggest problem I've had is needed Roadster and NEMA 10-30 adapters

@edavis008 - don't use the ebay one. That is the L14-30 where 'L' stands for 'locking'. It is NOT a dryer plug.

This is the one I made...
Uploaded from Photo Slice

I believe very few % of people needs HPWC. My build was finalized in early August and delivered in early December. Back in August, I considered the HPWC and decided against it. Now that I've had the car for 7 weeks, NOT going with the High Power was good decision for so many reasons. (1) I barely had enough AMPS coming into the house from PG&E to supply the 50 A for the NEMA 14-50. HPWC would have required PG&E to pull new cable to the house, very expensive. (2) I am getting about 23-24 miles per hour on the Nema 14-50. please realize there are several definition of "miles", and even the Model S display always lists two different kinds of "miles". I am using the definition of rated miles, i.e. on a regular charge, the highest rated mile is 240 (268 on max charge). At 24 miles per hour, the most it would take to reach 240 is 10 hours. I almost always have more than 10 hours. (3) since my average use per day is 46 miles, it only takes 2 hours. In fact, to avoid losing charge, I now always lower the Amp significantly so that my car is at 240 miles in the morning. I often use lower than 10 Amp, sometimes even 5 Amp. Who needs HPWC? Someone who drives 200 miles during the day, comes home for a couple of hours, and then needs to go drive another 100 miles.

@swysechoice - yes

One thing that people don't talk about where I think the HPWC helps is this - frequently, I want to head out on an out-of-town trip as soon as I get home from work. Depending on where I am going, I may need to recover the charge used by my commute, and I want to be able to leave as soon as possible. Cutting the time you have to wait in half isn't a bad deal, and then when you add the convenience of not having to pack/unpack the mobile connector and still have it with you in case of emergencies, it seems worth the cost.

Consider the Sun Country x-country network in Canada, 70A (free) all the way.

@nickjhowe - Your adaptor is BEAUTIFUL!! I didn't find a female 14-50 adaptor like this at Home Depot. Do you have to get these parts from an commercial electrical parts supplier or where?

I've been scouring ebay for a couple of weeks. It is easy to get them on commercial electrical sites, but they often want $100+ for the male, and another $100 for the female. If you are patient the come up on ebay and can be picked up for c. $20, as long as we don't all jump in at the same time!

The picture is the NEMA 14-30 plug; I've just got the 10-30 plug to make my other adapter. I coud have used stock dryer cords with molded plugs, but I preferred something a bit more robust.

Plus I picked up a NEMA 14-50p to 14-50r 30ft extension for $100 on Amazon. Tested it with the UMC and there's pretty much zero voltage drop. Now I should be able to charge at the two most common dryer outlets without any issues.

Probably never use any of them and the 50A extension is overkill but it is a cheap insurance policy. :-)

@nickjhowe - I want this insurance too. What's the difference among NEMA 14-50, NEMA 14-50p and NEMA 14-50r?

TM seems emphatic about not using extension cords. Is this simply a warning to scare people who might use inadequate extension cords?

@edavis008 - NEMA 14-50 describes the whole connector, and 14-50P is the plug while 14-50R is the receptacle.

There is technically no difference about having an extension cord and the wiring in your house -- ie plugging in on near your breaker box and running an extension cord will be the same as using the wiring in the house and plugging in nearer the car. The problem is that many people buy cheap extension cords, and they also aren't rated for continuous use -- most of the extension cords you buy for a regular 15A outlet aren't rated for anywhere close to 15A continuous.

If you use extension cords designed for RVs, and actually rated for 50A, you should be fine. Likewise if you are using a 6-50 adapter and using extension cords rated for 50A welders that would be fine as well.

A typical NEMA designation looks like L14-50r or 10-30p. In these examples the 10 or 14 refers to the type of connector, the L (or absence of L) indicates whether it is a locking-type connector, the 30 or 50 is the current rating and p or r identifies whether it is a plug or a receptacle.

14-50r is a fairly common 50A (40A continuous) outlet that is recommended for single inverter cars.
10-30r is a typical three pin dryer outlet that provides 24A continuous.
14-30r is a typical four pin dryer outletthat provides 24A continuous.

I think you are right about the 'scare' factor on cords.

There are many of you who know a lot about various kinds of connectors. Besides the 14-50 that comes with the Model S, what would be the next most likely plug we would find in the wild? 14-30? Then 10-30 is next?

Rather than make our own adaptor, What about this?

@Hills - that will work fine if what you need to plug it into is an L14-30, which isn't generally going to be in any house (the only place I have personally seen them is on generators and computer rooms for large UPSes).

I made 14-30 and 10-30 adapters, so I can plugin to dryer outlets at friend's houses if I need to. 6-50 would work for welders, if you have friends that weld. Beyond that, you aren't likely to get any use out of them unless you know a place with a specific outlet you want to be able to use.

Jat: Thanks. Ok, to plug into dryer outlet, I need non-locking kind of 14-30 and 10-30.

@Hills - correct. 10-30 is an older style receptacle. Newer ones (last 15 years) are more likely to be 14-30. To be on the safe side, if there is somewhere you are likely to go (my usual long distrance trip is to my mother in laws) ask them to send you a photo of their dryer outlet so you know in advance that you are OK.

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