200 vs 400amp service

[Rodolfo Paiz]

Given that you have a one-time-only $600 cost, absolutely get the 400A service. Run, don't walk.

You only get charged for the power you use. There are no economic or environmental downsides to having greater capacity. But upgrading later is always more expensive: sometimes dramatically so. I moved into a house with 200A service a year ago. Upgrading to 400A would cost me nearly $20,000 (for good and valid technical reasons that are not relevant to this thread).

It may really help you. It will certainly never hurt you. Don't think about it, just get it.

 

[Rodolfo Paiz]

I finished my basement (added second laundry room and small kitchen) and suddenly my 200 A service is maxed out. When I added second EV (model 3), I discovered that my charging options are very limited (I already had 50 A in the garage). I looked into upgrading my service, but between what the city wanted to charge, and what my electrician was saying, it quickly passed $5k mark.

I also have limited capacity. Bought a pair of "Share2-enabled" chargers from Clipper Creek, and put those on a single circuit. They'll allow each car half the power if both are charging at the same time, or will give one car full power if the other is not connected. Simplest way to address the issue for me. Hope that helps!

 

[bob_p]

While you can connect an HPWC to 100A - and if you have two Tesla vehicles, you could have 2 HPWCs connected to separate 100A circuits, based on the current battery pack sizes and charging rates, doing this is probably overkill, unless you have a need to rapidly recharge a vehicle in the middle of the day. For overnight charging, a 14-50 connector charging at 40A should be enough to fully recharge a vehicle overnight.

Most new Tesla vehicles only have 48A chargers onboard - so using an HPWC on a 100A circuit is overkill. When the electrician installed our HPWC last week, using the cabling already installed for our 14-50 outlet, he was able to change the breaker to 60A for the HPWC, since the cabling would support 60A - so now we're able to charge at 48A through the HPWC - which is more than enough to fully recharge overnight.

For two Tesla vehicles, a single 100A circuit is probably all you need. Gen 2 HPWCs can share a single 100A circuit, similar to how two charging stations are shared at a supercharger - and share 80A of current between the two HPWCs, again, more than enough to fully recharge two Tesla vehicles overnight.

Of course, it's possible future vehicles may have higher battery capacities and/or support higher charging rates - so if you're building a new house now, using 100A circuits may provide more flexibility to add faster chargers in the future. But for now, a 50A or 60A circuit is all that's really needed for overnight charging...

 

[dweeks]

Hi all - just wanted to get some opinions about the service to a new home we are building. Standard is 200amp service but I can upgrade to 400amp for $600. It’s a no brained right? I have a HPWC and my S85 has dual chargers so I will be pulling down 80 amps (on occasion). Other car is an ICE but hopefully we’ll be all electric soon.

I could deff get away with 200 amps today (our current house has 200) but for the future probably makes sense to go with 400.

Am I missing something or wasting money?

400 Amps.

When we built last year, we could have gotten away with 200, but I wanted a dedicated 100 amp line into the garage for the HPWC wall charger. That would have not left enough for the rest of the house. Hence, 400 amp service.

 

[Lasttoy]

U said you have dual inverters? You said the word "ocasion", ?? I have never seen a choice. When i plug into 100amp the car automatically goes to 80 amp draw.
I dont think u can draw more? Than 80amps?
The larger amp service is for multiple AC units on you house.

 

[Manzacoty]

U said you have dual inverters? You said the word "ocasion", ?? I have never seen a choice. When i plug into 100amp the car automatically goes to 80 amp draw.
I dont think u can draw more? Than 80amps?
The larger amp service is for multiple AC units on you house.

I can dial it down to draw whatever amps I want to pull from inside the car. I only pull the 80amps when I need to charge quickly.

 

[Manzacoty]

Thanks all for your input. I'm going to go with the 400 amps. I agree that I don't need the capacity today but I expect to have at least 4 EVs in the future (wife and kids). It's a fairly sizable house with a pool, electric oven, 5 refrigerators, etc. so for $600 its more of a future proof move to avoid hassle down the road.

 

[AudubonB]

If anyone else has been following this thread and is not yet convinced - think of your house's resale. In any future time greater than, oh, next month, the homebuyer looking at two otherwise identical houses will always not only be choosing the 400A house over the 200A one - but will be willing to pay far, far more than the minuscule additional cost of the at-build install price.

For new houses in the A/C belt - most of the lower-48 - that are above a certain size, 600A services are now not uncommon. When we were looking for a winter home away from Alaska, we did find one 800A 3ø beauty, but that was with quite an industrial-sized hobby auto workshop as well. BTW: after six years, it's still on the market....

 

[Dameon]

When I built my house a few years ago, I had our power company size for 600 amps. They put a larger, upsized, pad-mount transformer and ran wiring through an induction coil to meter. Apparently they only have/install 200 amp meter bases for residential connections. After passing through the coil, it goes into a wiring trough and I dropped down into (3) 200 amp disconnects. One goes to my shop and two go to my house. When I pulled my wire in the house, I made decisions on what I wanted protected by UPS/generator and what was unprotected. Stuff like the induction cooktop and Tesla charger were deemed unprotected, but stuff like the freezer and refrigerator were deemed protected. All lighting and all receptacles in the house are protected. I use a 200 amp ATS ahead of an APC Symettra UPS, fed by a generator/utility power, for the protected panel.

Probably more complicated then most, but since I was building my own house, I didn't mind investing the time and effort.

Like most have said, do the 400 amp service.

 

[ivan801]

I also have limited capacity. Bought a pair of "Share2-enabled" chargers from Clipper Creek, and put those on a single circuit. They'll allow each car half the power if both are charging at the same time, or will give one car full power if the other is not connected. Simplest way to address the issue for me. Hope that helps!

Thanks for heads up about share2-enabled chargers. I am thinking about doing 2 Tesla wall chargers and using an adapter on one of them to convert them to J1772. Either way I will end up using an adapter on one of the chargers...

 

[xyeahtony]

just adding my two cents but its the general consensus. 200A is deff more than enough for your needs today but with such a low cost to get 400A, go for it. Future proof the house because you never know how many EVs you'll have in the future. I live in a house right now with 100A service and i really wished it was at least 200A so i could install a wall connector with 72A charging.

 

[sorka]

It's a no brainer whether you keep your home or sell it in a few years. If I were looking for a house to buy now, I'd not consider any existing home with less than 400 amp service at this point so even if you sell in a few years, the resale value alone of having the upgraded service would be worth it.

 

[MD500_Pilot]

Hi all - just wanted to get some opinions about the service to a new home we are building. Standard is 200amp service but I can upgrade to 400amp for $600. It’s a no brained right? I have a HPWC and my S85 has dual chargers so I will be pulling down 80 amps (on occasion). Other car is an ICE but hopefully we’ll be all electric soon.

I could deff get away with 200 amps today (our current house has 200) but for the future probably makes sense to go with 400.

Am I missing something or wasting money?

I agree, no-brainer for $600. If you have two EVs @ 80A each charging at the same time in summer and want to kick on the AC and your dryer, you will really be happy you spent the extra $600! (IMO).

 

[bob_p]

U said you have dual inverters? You said the word "ocasion", ?? I have never seen a choice. When i plug into 100amp the car automatically goes to 80 amp draw.
I dont think u can draw more? Than 80amps?
The larger amp service is for multiple AC units on you house.

Early Model S vehicles came with a 40A charger. As an upgrade, you could add a secondary 40A charger, bringing the max charge to 80A.

Current S/3/X have a single charger, which is typically 48A, with some vehicles having 72A chargers (and some of the vehicles have 72A chargers and are being software limited to 48A).

 

[Manzacoty]

Early Model S vehicles came with a 40A charger. As an upgrade, you could add a secondary 40A charger, bringing the max charge to 80A.

Current S/3/X have a single charger, which is typically 48A, with some vehicles having 72A chargers (and some of the vehicles have 72A chargers and are being software limited to 48A).

Yup - mines a ‘13 with dual chargers. Wasn’t aware that the new ones were unadjustable.

 

[Jashev]

400A service for $600 is an absolute no-brainer! Even if you never use it.

 

[Feathermerchan]

If I never use it, I'd rather have the $600.

 

[bob_p]

If you're future proofing you EV charging, and you're building a new house, installing one or two 100A lines is much easier during construction than trying to add them later.

It's possible future EVs may have larger battery packs and/or support faster charging, either from Tesla or from other manufacturers. So if the cost of having the extra power available isn't too high during construction, it might be reasonable to do that up front and anticipate potential future need for higher power.

 

[Feathermerchan]

If you're considering one or two 100A circuits in your garage, you should really consider where the main panel is going to be installed. Overall it may save you money to have the panel itself in the garage.

 

[Manzacoty]

If you're future proofing you EV charging, and you're building a new house, installing one or two 100A lines is much easier during construction than trying to add them later.

It's possible future EVs may have larger battery packs and/or support faster charging, either from Tesla or from other manufacturers. So if the cost of having the extra power available isn't too high during construction, it might be reasonable to do that up front and anticipate potential future need for higher power.

Yeah - I'm running 1 100 amp line to one spot in the garage and a 50 amp line to the other side. The breaker box is in the 3rd car garage so it will be an easy add if we ever want to put anther one in there.