Picking Options - Twin Charging?

Picking Options - Twin Charging?

Finally took the plung and have my reservation number. Very excited!!!

Before I make my final options selections I was hoping to get some feedback from 60 kWh owners around true range and recharge rate.

For the most part I don't expect that I would travel more than 90 miles per day, so I opt'd for the 60 kWh battery. However, I'm trying to make the decision of whether to get the twin charging for the 1% of the times when I would have to travel >200 miles. I called some RV parks and found out that they have 220v 50amp outlets. However, my understanding is that I would only be able to use these if I had a high power connector and twin chargers.

1) Seems like most public charging stations are 30 amp? If that's true, is it everyone's experience that the recharge rate is ~23 mi/hr?
2) Is there a "mobile" high power connector that would allow me to take advantage of the 50amp draw at RV parks?
3) Does anyone have any experience/suggestions on how to get the best recharge rate when on a road trip?

If not, looks like even with twin charging I would only get the 31 mi/hr recharge rate when on road trips (not getting the supercharging option).

tylerhen | May 7, 2013

You don't need the twin chargers to charge at RV parks. You should get ~32 mi/hr at an RV park on a 50 amp outlet.

I currently plug my 60 kWh into a dryer outlet(220V 30A) and get about 17 mi/hr, which is fine for completely recharging overnight.

On a standard charge, you get 190 rated miles.

The twin chargers come into play when you plug into an 80 amp outlet which is what the high power connector is. From what I have read on the forums, most people opted not to get the twin chargers and are completely satisfied with our charging capabilities.

DouglasR | May 7, 2013

Where do I start? Twin chargers won't help you at the 50 amp outlets in RV parks, but neither do you need a High Power Wall Connector (HPWC) to use these outlets. The NEMA 14-50 adapter that comes with the car is all you need for these 50 amp outlets. They will charge at about 24-29 rated miles/hour (or up to 31 ideal miles/hour), depending on voltage and other conditions.

Twin chargers will help you if you charge through an HPWC in your own garage (where you will rarely need it because you usually are charging overnight) or at a TM showroom/service center, where it will sometimes come in handy on road trips. Twin chargers will also help you at 70 amp J1772 stations, which you will find across southern Canada and at a handful of other places throughout the U.S. Twin chargers will also help you at a number of 70 amp Roadster chargers around the country, but they require an adapter.

Most public charge stations have a J1772 connector and provide about 30-32 amps. This will give you around 18-20 rated miles/hour. If you set your units to "ideal" miles, your car will display a faster charge rate, but it is not realistic.

I don't know where you live, but in most places, the supercharger option is a better way to spend your money than twin chargers and an HPWC.

cmaso | May 7, 2013

Thanks for the feedback. Specifically I'm concerned about the road trip scenario, b/c 17mi/hr isn't going to cut it.

I'm under the impression that a 50A outlet at an RV park will give me ~38 mi/hr. Here is the math I used (hope it's not flawed)...

31 mi/hr divided by 40A = .775 mi/hr/A
.775 mi/hr/A * 50A = 38 mi/hr

But sales rep is telling me that requires twin chargers. If that's the case, is it reasonable to assume that with the twin chargers and 50A I would get ~38 mi/hr?

ChrisPDX | May 7, 2013

The 50amp rating is peak, not continuous. You are only allowed to draw 40amps continuous from an 14-50 outlet per code. This is also why Tesla requires the circuit powering a HPWC to be rated at 100amps when it only draws 80amps.

DouglasR | May 7, 2013

No. Sales rep is wrong. The 50 amp outlets at an RV park deliver at most 40 amps (you need to derate to 80% if load is continuous). A single charger will handle this: 40A x 240V = 9.6 kW. Often the voltage is less -- 208 -- so you don't get the full 9.6 kW.

The 50 amp RV park outlet at best is the same charging rate that I get in my garage with a NEMA 14-50 outlet. That is 24-29 rated miles. The 31 miles used by TM is "ideal," but you won't typically get that.

For road trips, stick with NEMA 14-50 and you will be fine, but not 38 mph.

carlf9121 | May 7, 2013

I picked the twin charger option at the time of configuration but did not purchase the HPWC for my home as my daily mileage of 30~50 miles can easily be covered with the UMC provided with car. I felt it was important to have at your finger tips the capability of using the TM showroom or service center HPWC while on road trips or while shopping at Santana Row in SJ. More & more TM showrooms & service centers will open to match the success of Telsa ownership. This opens more opportunities of charging at the most efficient rate at zero dollars.

Must cheaper to have it installed at configuration at $1500 vs. having it done later after taking vehicle delivery at $3600.

Something to consider....

DonS | May 7, 2013

Right now the twin charger is not very useful because there are so few chargers over 40A. In fact, the major networks, Chargepoint and Blink, have no plans to increase over 30A because the existing market (i.e. Volt and Leaf) doesn't need it. For the Model S, 30A at 208V takes 12 hours for a standard charge on the 85KWh battery. This is stupidly slow, and no one but Tesla understands that faster charging is required if you are away from home.

I bought twin chargers because I plan to keep this car a long time. I have strong hope that the Tesla sales will eventually drive some provider to setup chargers at the 80A max that is listed in the SAE standard.

mbornstein | May 7, 2013

Similar topic, different question. At home I have a 40A Leviton charger, so I would not use twin chargers at home. On the road there are the SuperCharger stations, again no need for twin chargers. The big question is, are there enough 70-80A public charging stations out there that would make it practical to add the twin charging feature. I found an old Google Map dated 2011 that did show several of these stations, but are they still around? Do any of the EV mapping services list the 70+A stations separately so that one can plan a trip based on the availability of these fast chargers?

dano | May 7, 2013

All of the chargers at Rabobank are 70A. Many of these are along the 101 in California, so until we get more superchargers, they're the next best thing. Of course, you can only use these at the high capacity if you have the twin chargers. Oh, and they're also free.

DouglasR | May 7, 2013

Here are two maps:

There are other 70 amp stations not on these maps, but this should get you started.

ghillair | May 7, 2013

The J1772 standard is good up to 90 or 100 amp. Most installed sites have opted for low capacity because there was no demand (no production vehicle before the MS) that needed it. Obviously it is cheaper to install a 30 or 50 amp circuit rather than 100.

There is a Canadian company (Sun Country) making 90 amp chargers and have had success installing than all across Southern Canada.

The challenge to the Tesla user community is to encourage (demand) the charging sites to install these high power chargers, can be other than Sun Country. In a few years they will become more common and allow for travel off the super charger network.

Note, not all chargers are 90 amp.

herkimer | May 7, 2013

Well, the Tesla product specialist I talked to definitely discouraged me from choosing the twin-chargers, saying that they would not be necessary unless I needed a quick charge during the day using a HPWC.

Reading this forum, I am feeling like I made a mistake in not adding the twin charger. Of course there are actually not any J1772 chargers or Roadster chargers or any other high power chargers anywhere near where I live. So I will be charging mainly at home or in RV parks or on someone's dryer outlet.

Of course, sometime I may want to take a journey somewhere that does have high power chargers, like southern Canada. Also, I will not be able to take advantage of TM service centers and showrooms in cities I may be visiting. Hard to justify paying $1500 to very occasionally be able to use a high power charger, until that time comes when it would make the difference between an hour or two, and 4 or 5 hours charging somewhere (yikes not looking forward to long charging wait times!)

Mark K | May 7, 2013

Ironically, twin chargers may be most useful for (the few) 40kWh buyers.

Because you have less capacity, a midday refill may be useful. If you shuttle from home on a lot of short trips, (my wife is like this), then you can refill in 30 to 60 minutes at home. This greatly extends the useful range of a 40.

If you have a 60 or 85, and need to refill before going out at night, fast home charging can also be a help.

Definitely not essential, but may be useful depending upon your lifestyle.

mrspaghetti | May 7, 2013

@DonS +1

Consider the twin chargers "future proofing"

DouglasR | May 7, 2013

The Sun Country charger is actually made by Clipper Creek in Auburn California.

Alex K | May 7, 2013

@ghillair | MAY 7, 2013: The J1772 standard is good up to 90 or 100 amp[...] There is a Canadian company (Sun Country) making 90 amp chargers and have had success installing than all across Southern Canada.

Actually the J1772 standard only goes up to 80A. The 90 & 100 amps you are referring to is for the breaker capacity. The Sun Country CS-90 and CS-100 chargers are actually 70A and 80A continuous duty (

drp | May 7, 2013

I drive a lot and have twins and HPWC. Both are great for me. After a day out I can get home with <50 rated remaining and it's great to get a jolt while I shower and dress to head out running kids around etc. well over 50moh charge.

drp | May 7, 2013

The small consolation is that I always have a cord at home and always have one in the S as well.

Brian H | May 8, 2013

BION, someone bought the HPWC and not twin chargers, because it's convenient and looks good. Only hooked up to 50A, though.

RyanMN | May 8, 2013

Since all the cars come with Supercharger now, I would opt for Twincharger, and not get the supercharger until they actually enabled superchargers in your area. Unfortunately it wasn't announced that all cars would come with superchargers and it was a software switch to turn it on when I got my car, so I did the opposite and am regretting it. I live in MN where there are no superchargers its 2k invested into something that might not ever happen, where as 80amp public chargers will definitely happen.

mrspaghetti | May 8, 2013


I'd have more doubt about the availability of 80amp public chargers than the supers. At least, if the high-amp public chargers ever become widely available it won't be for a long time.

The SCs, on the other hand, are in progress as we speak. Not sure where your pessimism is coming from about that.

Brian H | May 8, 2013

It comes from living in fly-over-land, I bet.

wraithnot | May 8, 2013

If you are choosing between supercharging and twin charging, I'd definitely suggest choosing supercharging. In a little over two months of ownership of my 85 kWh, I've made 10 supercharger visits (4X Gilroy, 2X Harris Ranch, 2X Tejon Ranch, and 2X Barstow). I have not been in a situation where twin chargers would have helped me out. However, I do have some slight regrets about not opting for the twin chargers after reading about some Tesla owners taking things into their own hands and installing HPWCs for other Model S owners to use: If enough of these HPWCs get installed in places I want to go and there are no nearby superchargers I may pay the extra money to install the second charger.

cmaso | May 8, 2013

Thanks for all the feedback. My head is spinning.

What I've learned from this post and a few other's I've read:

1) J1772 (30A) & NEMA 14-50 (50A): With single charger or twin charger I would get the same recharge rate (aprox. 14-16 mph or 24-29 mph respectively), b/c it's a 24A or 40A draw (40A being the max draw a single charger can accept)

2) J1772(70A) (not sure if it's a "J1772", but it's a 70A or 80A circuit)- least common (souther canada, Cali and a few roadster recharging station (Wish I had found a map of 70A charging stations that I could share, but still looking), and adapter maybe required ~650 (not sure if that's just for the roadster stations or any 70A station): requires twin charger to increase recharge rate above the 24-29 mph of the 50A circuit. I think a 70A would get you ~42-50 mph. I am still unclear if there is anything else I would need to buy to take advantage of 70A charging stations...

Argument against TC:
1) Supercharging (if available)
2) Most charging stations are currently either 30A or 50A - single charger and twin charger will recharge at the same rate on either of these circuits.

Argument for TC:
1) It's a $1,500 insurance policy to cover "who knows what the future holds", if the future holds more 70A or 80A charging stations.
2) Continuation of #1 - There might be after-market products in the near future that would allow you to plug into two 50A outlets and give you the 80A you need to max out the recharge rate. See

Assuming I have all of that correct, for me the Pros outweigh the Cons.

Going to call Tesla and will update my post if I learn anything new.

dsecrist | May 8, 2013

To clear up your adapter confusion in #2 above, you only need the Roadster to Model S $650 adapter if you want to use a Roadster HPC to charge your Model S. If you are lucky enough to find a 80A J1772 charger, then you would use the J1772 adapter that comes with the Model S.

RyanMN | May 8, 2013


No announcements of locations outside of the coasts are a big factor in my lack of faith. I would think if they "are in progress as we speak" we would have a good idea where they would be built by now and when.

Objective1 | May 8, 2013

@RyanMN Normal Il has approved SuperCharging deal with Tesla. When it will be operational we don't know.

DouglasR | May 8, 2013

@cory - If you look at the Google map I posted above, you will see it has red, blue, and yellow pins. The red pins are supercharger stations. The blue are 70 amp stations. Click on the pins to get longer descriptions, including whether an adapter is needed. The yellow pins represent just a small sample of other sources, mostly 50 amp. The map was put together by Chad Schwitters from Seattle, so it focuses mostly on the west coast. Check out recargo or other sites/apps to find 70 amp stations elsewhere.

Where do you live, and where are you intending to drive? I live in Seattle, and drove to northern California and back using only free 70-80 amp stations. I borrowed an adapter (several people in local forums offered to lend, since they are not needed that often). Of those stations, most were Roadster stations (proprietary connector, which is why an adapter is required), one was Model S HPWC at the Oregon Tesla store. I didn't use any 70 amp J1772 stations, but I know there is one up by the Canadian boarder, and several new ones will be going in in eastern and central Washington.

cmaso | May 8, 2013

I live in N.Virginia (just south of DC and work near Dulles Ariport). Like I said 99% of my driving will be >90 mi per day... However, we spend a lot of weekends at a lake in south western VA, about 230 miles from home. We have an MDX for road trips, but there could be situations where the family goes down for the week in the summer, and I have to drive down myself later in the week.

The drive is already 4.5 hours, so adding another 2 hours to that would stink. If $1,500 can potentially reduce that to only adding 1 hr (if the stars align and there is 70A station), then I think it's a good investment...

Brian H | May 8, 2013

The second charger can be added later, and SC can be activated later, both for about a $500 premium over the original costs.

DouglasR | May 8, 2013

@Brian - Actually the second charger is $3,600 plus tax to add later, but only $1,500 (no tax for me) if ordered with the car.

Brian H | May 8, 2013

Yow. Big diff.

ian | May 8, 2013

Yup. Parts plus labor for the install. Much cheaper to have it installed while the car's being put together than to have to tear it apart all over again later! ;-)

chicago.ev | May 9, 2013

The rep at the Tesla store told me that the price($2000) for the SC option on a 60kw model would be the same pre- or post-delivery. Was she incorrect?

Keith72 | May 10, 2013

I opted for the twin chargers for future possibilities, not for current needs. My roughly 30 miles per hour charge in my garage will completely charge the car overnight even if I run the batteries to their low limit. I live in the Houston area, and would take the car to Dallas, San Antonio and Austin if I was comfortable that I could pick up a few quick miles by stopping and briefly charging somewhere along the way. Currently no superchargers in Texas (hopefully some by the end of the year), but if an 80 to 100 amp charging station is within easy access of a highway, then the twin chargers will come in handy. I also thought they might have some value if I decide to sell the car sometime in the future (although I can't envision ever selling the car since I love driving it).

splitsec002 | May 10, 2013

I have a real world driving story I'd like to share. I have a 60 and I did a LA to San Diego Trip just yesterday. On google, my total mileage from LA to SD was 160 miles. I did a max charge and ended up with 202 miles to start from my house. Started the trip in the morning and heading to SD. I usually drive about 80 mph and have the radio blasting and AC at 70 degrees. We did 1 stop for a rest room break that was right off the freeway. At one destination we got lost and probably wasted 3 miles max. The last point of the trip was to go to the Tesla Store in San Diego to charge up while we had dinner. I was supposed to have around 40 miles left when I got to Tesla but I got there with 2 miles left.

Bottom line, even the rated range in real world driving conditions won't give you the real mileage. It might if we all drove 55 but I doubt anyone really drives 55 these days. Especially in this car.

If I was to do it all over again, I would of paid the extra 10k for the 85kwh. I worked out the math and it would of been about an extra 166 a month which I definitely could of afforded. I was trying to figure what I would need at the most and 60 was plenty. But it wasn't enough for my road trip.

Worst part of this story was the end. Tesla closed at 9 and I didn't have enough energy to get home. Stopped in Irvine to charge and the GE charging station would not work. Ended up taking a taxi home and coming back the next day to charge at a car dealership @17 mph.

Moral of the story. If you can afford the payment, get the 85kwh. I wish I did.

Brian H | May 10, 2013

would have
could have

The "margin of error" with a 60 is less, so your experience is not a surprise. Imagine the difference, though, as SCs become more common. Your problem may go away.

splitsec002 | May 11, 2013

It was sort of a surprise. I'm just saying, get the biggest battery pack you can afford. The day to day use with this car is awesome. Nothing in the world like it and I love my car. Just wish I got a bigger pack.

shilo_js | May 11, 2013

If configured with supercharging, can you add the twin charger later and have both supercharging and twin charging?

ian | May 11, 2013

@shilo - Yes you can but it's quite a bit more expensive to add the second on board charger (the "twin") than it is to add it during the build. All cars come with the supercharger hardware installed. It's just a software "switch" to activate it. The twin charger is actually a second onboard charger and is not on every car. You have to ask for it.

There seems to be quite a bit of confusion out there regarding the supercharger and the twin charger. Yes there is a difference folks! Do some more research on the car before purchasing!

@chicago.ev - That's a good question. I thought I read somewhere that they were charging more to turn on the supercharging after delivery but I may be wrong.


tcampos | May 12, 2013

I opted both for the Twin Chargers and the HPWC and I am REALLY happy that I did. First off, I do not drive that much during the week. I typically travel between 30-40 miles/day. Well within the range of a normal charging setup. Moreover, I can charge my car at work and typically do so home charging isn't that necessary. However, I do occasionally travel far (we live in the south bay, just recently did a trip all the way up to Napa). Weekends also tend to be really busy schlepping the kids to soccer, etc.

Where the HPWC has come in super handy for me is when I need a quick charge, or when I am just stupid and forget to charge. It is 3x faster than the charging stations at work and 2x faster than the fastest setup on the mobile connector. That helps me recover range really quickly and it gives me a lot more flexibility. The other day for example, I had 90m of range. I was planning to head out from work in the afternoon for a longer trip and at 17milescharged/hr, it meant my best case scenario was that I would have 190miles after 6 hrs charging at work. I plugged my car in before taking a shower, got 45 mins of charging before heading to work, and that meant I could leave work 2.5 hrs earlier.

Key point is that HPWC enables flexibility, just like the larger battery does. I also believe that the twin chargers could be useful in the future with more model-S on the road.

Anyway, hope that helps

Brian H | May 12, 2013

Smart summary.