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Dual charger useful when away from home?

Would you get a dual charger if ordering the Model S now?

  • Yes

    Votes: 50 64.9%
  • No

    Votes: 27 35.1%

  • Total voters
    77

davesm

Member
Dec 24, 2015
69
8
Massachusetts
I haven't been able to find any recent dual charger threads, and just ordered a 70D, and would appreciate any advice on whether to get one.

I understand that a dual charger is not needed for Superchargers (of which there a fair number of coming out of the Boston area), nor for CHAdeMO, which I gather is an up and coming charging protocol, but that it would be useful for public AC charging at >40A. So I suppose my question is what percentage of public charging stations are >40A (particularly in New England) for which having the dual charger would be useful?

And, BTW, for home charging, it seems to make sense to get the HPWC regardless (since I would want to keep the mobile charger in the car), so assuming we can get a >80A circuit installed (TBD), then I know the dual charger could be useful at home, but, for driving only ~40mi/day, it seems that it wouldn't be needed most of the time... (though I can envision the possibility of having used the car right before taking a road trip and wanting to give it a full range charge while doing last minute packing!)

Thanks for any and all advice. Very excited to be getting this car, and now just need to figure out the needed accessories!
 

dsm363

Roadster + Sig Model S
May 17, 2009
18,278
151
Nevada
There are very few 80A public charging stations out there but they can be useful. If you are in a city with a Tesla store or maybe another Tesla owner with a HPWC and no nearby Supercharger then it will cut your charging time in half. That said it is likely not necessary to have but nice to have for most people.

It sounds like you wouldn't really need it at home but like you said it is nice to have. You can keep your UMC in the car so on trips you don't accidentally forget it at home. The install looks nicer and the cable is longer as well. There also might be the rare time you drive 200+ miles and come home almost empty and need to turn around again quickly. Also, if you have Tesla friends visiting they can charge up quickly as well if they have dual chargers of course too. Congrats on the car!
 
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msnow

Active Member
Jul 14, 2015
4,951
2,236
SoCal
There's also no rush to decide. I had planned on ordering one as soon as my car was delivered but after having it for a couple of months I haven't yet found the need. Suggest you do what your doing and see if your potential destination chargers could benefit from dual chargers but take your time.
 

davesm

Member
Dec 24, 2015
69
8
Massachusetts
That's a good point. There's no extra cost to have it installed after you have the car? The only thing is that we need to hire an electrician to install the HPWC, and we need to decide the amperage for that circuit...
 

msnow

Active Member
Jul 14, 2015
4,951
2,236
SoCal
That's a good point. There's no extra cost to have it installed after you have the car? The only thing is that we need to hire an electrician to install the HPWC, and we need to decide the amperage for that circuit...

Compare the quotes between the various Tesla recommend electricians or your own electrician. I had 3 bids and asked to quote on both 50 and 100 amps. For my situation it was $650 for 50 and $1500 for 100 because it required its own service and meter although the electric company would credit half the cost of the 100. In the end I picked the 50 and since I'm retired and don't drive a lot it works for me. If you get the 100 amp circuit you can still set your car to 40. It's not going to let you "over amp" it. Also see what your electric company will provide in rebates and "Time of Use" rates. Good luck and congratulations.
Yes, you can have the dual charger installed at your Service Center any time you want, no extra cost versus doing it now.
 

BertL

Active Member
Aug 19, 2015
2,018
1,573
Carlsbad, CA
That's a good point. There's no extra cost to have it installed after you have the car? The only thing is that we need to hire an electrician to install the HPWC, and we need to decide the amperage for that circuit...
A dual charger today is a post-delivery option, only. There is no cost difference as to when you have it installed if you ever do.

If you are going to have a HPWC installed, and believe you may want 80A service one day, I'd go ahead and have the conduit/wiring/breaker work done to support it. The HPWC can be set up to use 80A, but if your MS only has a single charger, everything will work fine -- it will just use up to 40A. I had my HPWC installed with a 100A circuit while my S90D was being built, and it worked on the day of delivery when I brought my MS home, and required no changes to my MS or HPWC when I returned the next week after having the dual charger installed. The 100A circuit is perhaps going to cost you slightly more money because of a bigger breaker, thicker wire and bigger conduit -- but those things would need replacing if you ever change your mind starting small with 40A and want to increase it later -- check with your electrician on the cost delta. A reason you may NOT want the dual chargers is if your home panel is maxed-out and can't handle a new 100A circuit -- that could be thousands of dollars to upgrade your panel, vs just adding in a 40A circuit that hopefully you can fit in without a problem. Those are at least the considerations I went through this past September.... Hope that helps. Congrats on your new MS!
 

Max*

Charging
Apr 8, 2015
6,670
3,719
NoVa
I think it depends on your specific circumstances. Most of the trips I take are on the SpC network, so dual chargers wouldn't be useful.

I had one time where I wished I had dual chargers. Went to Myrtle Beach for vacation, and booked my hotel before I ordered the Tesla. Once I get to the hotel, only charging option is a 120V outlet (which I was thankful for). But the nearby hotel/restaurant had an 80A HPWC, which I frequented, but since I only had a single charger, it maxed out at 40A...
 

Larry Chanin

President, Florida Tesla Enthusiasts
Aug 22, 2011
4,909
753
Sarasota, Florida
I haven't been able to find any recent dual charger threads, and just ordered a 70D, and would appreciate any advice on whether to get one.

I understand that a dual charger is not needed for Superchargers (of which there a fair number of coming out of the Boston area), nor for CHAdeMO, which I gather is an up and coming charging protocol, but that it would be useful for public AC charging at >40A. So I suppose my question is what percentage of public charging stations are >40A (particularly in New England) for which having the dual charger would be useful?

And, BTW, for home charging, it seems to make sense to get the HPWC regardless (since I would want to keep the mobile charger in the car), so assuming we can get a >80A circuit installed (TBD), then I know the dual charger could be useful at home, but, for driving only ~40mi/day, it seems that it wouldn't be needed most of the time... (though I can envision the possibility of having used the car right before taking a road trip and wanting to give it a full range charge while doing last minute packing!)

Thanks for any and all advice. Very excited to be getting this car, and now just need to figure out the needed accessories!

Hi Dave,

Congratulations on your upcoming delivery.

To answer your question we have to be able to predict the future. However, we have some points that Elon and Tesla have made to guide us. In a few years they tell us that the number of Teslas added to the roads will increase by over an order of magnitude, year after year. The questions is will Tesla be able to keep up with Supercharger expansion to deal with that influx of new Teslas? If Superchargers become congested destination chargers will take on added significance.

Last year Elon stated at a press conference that the number of destination chargers would in the long-term be 10 times the number of Superchargers. Obviously, Tesla is hedging their bets by offering alternative to Supercharging. I assume they have a reason for that.

Here in Florida the vast majority of existing destination chargers are near the full capacity of an HPWC. Perhaps it would be worth your while to research the situation in your neck of the woods. Here's the Tesla map of your area. I haven't done an exhaustive search, but it looks like half the destination chargers in your state are at full capacity.

If in the future there are lines at Superchargers people will be spending more time at destination chargers as an alternative. If there's a line in front of you at a full capacity destination charger, even if you decided not to go with dual on-board chargers, you're going to be happy that the owners in line in front of you chose to install them. :wink:

As was pointed out, currently this is only available as a retro-fit option installed at a service center. So you can wait to make the decision if you wish.

Personally, I find this current ordering policy to be dubious, because the service centers are already becoming over-taxed and they don't need this unnecessary workload. I think that Tesla should resume the original ordering policy and permit new owners to order dual chargers as a factory option.

Larry
 

mikeash

Active Member
Oct 26, 2014
1,105
699
Fairfax, VA, USA
I don't have dual chargers and I don't miss it. I've plugged into a >40A L2 station exactly once, when going to the beach. Charging at 40A got me well more than what I needed in the time I was there, so I didn't need the extra. >40A stations are just not very common in the wild.

Clearly, there are cases where you'd really want it. If you have a route that needs a charge in the middle and there's a high-amp L2 station at the right point then dual chargers could save you a lot of time. But for most people, that's a really unlikely scenario. I think that if you're going to be making a trip like that, you'll know well in advance and won't need to ask the question.
 

ecarfan

Well-Known Member
Sep 21, 2013
19,197
13,850
San Mateo, CA
I recommend getting Dual Chargers if you can afford it, they are useful now and they will only become more useful in the future as more higher amperage destination chargers become available.
 

Rockster

Active Member
Oct 22, 2013
3,010
4,613
McKinney, TX
Every time I've charged at a non-Supercharger charger outside of my home it's been at 80 amps and I've been very happy to have that increased charging speed. Similarly, I think everyone who has found my charger on Plugshare and stopped by the house has been glad when they could charge at 80 amps. It wouldn't take too many charging stops at 1/2 that charge rate to make me regret the savings of one onboard charger versus two.

And even though I charge at 42-50 amps at home most of the time, for those occasions when we deplete most of our charge during the day and want a fast turnaround to leave town in the evening, the dual chargers are quite a blessing.
 

msnow

Active Member
Jul 14, 2015
4,951
2,236
SoCal
Every time I've charged at a non-Supercharger charger outside of my home it's been at 80 amps and I've been very happy to have that increased charging speed. Similarly, I think everyone who has found my charger on Plugshare and stopped by the house has been glad when they could charge at 80 amps. It wouldn't take too many charging stops at 1/2 that charge rate to make me regret the savings of one onboard charger versus two.

And even though I charge at 42-50 amps at home most of the time, for those occasions when we deplete most of our charge during the day and want a fast turnaround to leave town in the evening, the dual chargers are quite a blessing.

What's the reason you don't always charge at 80 at home?
 

LetsGoFast

Active Member
Oct 13, 2014
1,329
101
Virginia
I have used it only rarely. I have twice encountered 80A destination chargers outside my home. Despite this, I think it was a good purchase because there have been a few times where the speed of dual charging at home made the difference between being able to make a last minute trip in the Model S and having to take the ICE.
 

smilepak

Active Member
May 11, 2015
1,710
514
Eastvale, CA
I haven't been able to find any recent dual charger threads, and just ordered a 70D, and would appreciate any advice on whether to get one.

I understand that a dual charger is not needed for Superchargers (of which there a fair number of coming out of the Boston area), nor for CHAdeMO, which I gather is an up and coming charging protocol, but that it would be useful for public AC charging at >40A. So I suppose my question is what percentage of public charging stations are >40A (particularly in New England) for which having the dual charger would be useful?

And, BTW, for home charging, it seems to make sense to get the HPWC regardless (since I would want to keep the mobile charger in the car), so assuming we can get a >80A circuit installed (TBD), then I know the dual charger could be useful at home, but, for driving only ~40mi/day, it seems that it wouldn't be needed most of the time... (though I can envision the possibility of having used the car right before taking a road trip and wanting to give it a full range charge while doing last minute packing!)

Thanks for any and all advice. Very excited to be getting this car, and now just need to figure out the needed accessories!

I have had the 70D for the past 6 months. I would have to say the need of a dual charger for me is not important. Luckily I didn't have to spend extra money to get it. The normal 40a overnight charging is good enough for me. On the road, I use the Super Charger or CHAdeMo stations, both have been pleasant experience.

In the past 6 months, I only use the typical L2 charger on the road less than a doz time. That was on purpose just to maintain battery while I was at a mall shopping and they happen to be available. Been driving fro Oxnard to San Diego a few times and all over southern california w/o any issue.
 

RDoc

S85D
Aug 24, 2012
2,723
1,571
Boston North Shore
I'd suggest waiting to see how you use the car and if there actually are any HPWC or 90A J1772 chargers near you. In my case, I've yet to seen any use for dual chargers.

I'm a lot more interested in a CHAdeMO or CCS adapter (if they are every released). Even 80A L2 is awfully slow.
 

jerry33

(S85-3/2/13 traded in) X LR: F2611##-3/27/20
Mar 8, 2012
19,593
22,086
Texas
What's the reason you don't always charge at 80 at home?
The usual reason is to be nice to the power company and the neighbourhood. Also the HPWC heats up less.

- - - Updated - - -

I've never used it. Probably my biggest waste of money, ever.
I've used it at destination chargers and PlugShare locations. Glad I have dual chargers.
 

AWDtsla

Active Member
Mar 3, 2013
4,262
3,952
NE
I wish it was useful. Every charger I've encountered so far has been putting under under 6kW and there's usually a Volt attached to it charging at 3.3kW all day.
 

SW2Fiddler

We Are Cognitive Dissidents
Mar 19, 2014
2,362
3,247
Houston TX
Have an HPWC on a 70A breaker and so charge at home at 56A, which is 14kW at the car.
Yes I would get dual chargers in a new S because "time-to-charge" is one of the very few drawbacks of an electric car; why wouldn't you minimize the drawbacks that you can do something about?
 

Gizmotoy

Active Member
Sep 16, 2013
3,657
859
Bay Area, CA
I recommend getting Dual Chargers if you can afford it, they are useful now and they will only become more useful in the future as more higher amperage destination chargers become available.
Is that actually happening? I get the distinct impression that DC fast chargers are rolling out pretty quick, but high-amp L2s are not. I've had my car two years now, and have not yet encountered an 80A L2. Even the HPWCs I've used over the years have all been 40A limited.

From my perspective, you'd be better off spending that money on a CHAdeMO adapter (and SCC, if that becomes popular and we get an adapter).

The only way I'd order the dual chargers now is if I lived along the Sun Country Highway in Canada, or if I often needed fast recharge times at home. Otherwise, even if it gives me legitimate benefit a dozen times over the life of the car (extremely optimistic given 2 years without any usage), that's still $160 a charge. It's probably unlikely that each of those sessions was worth the extra cash. Even finding a list of 80A chargers is difficult: plugshare, at least on the mobile app, just lumps them all together and you have to comb through comments or tap each one to find what's 80A.

So in summary, you need to take a closer look at how you plan on using the car to determine if it'll be worthwhile.
 
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