two tesla charging

two tesla charging

I currently own MS and plan to get MX before the end of the year. Would you recommend two nema14-50 outlets with each one having its own 50 amp circuit or is there an option to connect both cars to one 50 amp circuit

ratchet | 1 août 2017

Using the supplied Mobile Connector, you would be able to plug in only one vehicle at a time if you had a single NEMA 14-50 wall outlet which would require manually disconnecting the Mobile Connector from one vehicle and moving it to the other. Depending on your charging schedule, it might be a hassle if you want to charge both vehicles overnight. If you have the capacity in your breaker box, you could install a second NEMA 14-50 circuit and allow both vehicles to be charged at the same time. A more expensive option would be to purchase and install two Wall Connectors and have them linked together. You would feed both of the Wall Connectors from a single circuit (up to 100 amps but they can be programmed for less) and they would share using the available power from the circuit. Your best option might depend on the capacity of your breaker box. If you cannot add another 50 amp circuit without adding a sub-panel, you can keep the single 50 amp circuit that you already have installed. In that case, you would choose between the inconvenience of manually moving the Mobile Connector cable or installing two Wall Connectors. If you can easily add a second 50 amp circuit, you could go for a second NEMA 14-50. If you can upgrade your existing circuit and cabling to 100 amp service, you could install two Wall Connectors and charge both vehicles faster (depending on whether either or both vehicles can handle a higher charging rate.

Model_D | 1 août 2017

Here is what we do: We have one cable plugged into a NEMA 14-50 (9.6 kW) and one plugged into a standard outlet (1.44 kW). Whichever vehicle needs a faster charge gets the 9.6 kW. Our electrical panel can't handle any more than that. It works for us.

ken | 2 août 2017

I added a sub panel and make two 50A each, adding sub panel is a good idea cause at some point you going to need to run power to something

Jeff A | 2 août 2017

Depending on your panel load capability you may want to consider replacing the NEMA 14-15 with the HPWC from Tesla. You can share multiple HPWCs on a single circuit. For multi-charging scenarios this offers one unique advantage, the HPWC will load balance so to maximize the charge rate between the two cards within the current boundaries of the circuit. Say for example you have a panel with enough for 80 amps, per code you can pull 64 amps on this circuit. If you have two cars charging, the HPWCs will balance themselves to supply 32 amps to each car. If one car finishes then the remaining car will ramp up to the max possible charge rate.

In addition, all Teslas sold today come with a 48 amp on board charger, NEMA 14-50 cannot maximize the charge capabilities of your charger since the standard is limited to 50 amp (40 am delivered) -- the HPWCs can, if your panel has room for it, charge up to the full 48 amp delivered. It is a bit extra money, but you do get 20% faster charging.

Of course if you have 100 amps of space on your panel, then 2 NEMA 50's will always give you 40 amps of charging.

dortor | 3 août 2017

I have two HPWCs sharing a 60 amp circuit it works well. Plug both cars in and they just share the load until one car is full then the remaining car gets the full 48 amps until it's full - you can have up to 4 HPWC share this way - 1 master and 3 slaves - this is the way to go IMHO.

dortor | 3 août 2017

I have two HPWCs sharing a 60 amp circuit it works well. Plug both cars in and they just share the load until one car is full then the remaining car gets the full 48 amps until it's full - you can have up to 4 HPWC share this way - 1 master and 3 slaves - this is the way to go IMHO.

COrich | 3 août 2017

I installed 2 NEMA 14-50 outlets, each on their own circuit when we were preparing for the delivery of our X. That second outlet is to support charging of the 3 we hope to get later this year. The 40 charging is plenty for the X even if I have to charge from 20% to 90% over night (of course, we only pay $.10 per kWh so the overnight charging can take 10 hours if necessary).

The 14-50 outlet gets me 26 Miles per hour of charging on the X.

ir | 4 août 2017

My panel barely has capacity for a 50A charging circuit. I installed 2 HPWCs in load sharing configuration and they work well.

Only downside is that a plugged-in non-charging car reserves 6A capacity. Leaving only 32A for the other car. This is a limit of the J1772 protocol because it doesn't allow a station to advertise "zero" power for charging and still be ready to charge.

If I really need full power charging for 1 car I would have to unplug the other one (rarely happens).

cdavidhord | 4 août 2017

I recently installed two HPWC in our garage. I purchased #3 copper to supply 90 amps to load share. The inspector wanted a "cut off switch" on the circuit in the garage within sight of the chargers. It would not be required for 60 amp circuits or less. The cut off switch was not attractive. We returned the cut off and just purchased another length of THNN #6 and ran all 6 wires in 1.25 inch conduit. I have one circuit with #3, and one circuit with #6. Currently I have 60 amp breakers on each. I can just change the 60 to a 90 to get the max 72 amps on that HPWC now that I'm past the inspection. I think its best to just have two dedicated circuits rather than do the load sharing. The cut off switch was not attractive and added a couple of extra conduit sweeps at made it even more of an eyesore. Once you have the conduit in place, the cost of the #6 wire for the second circuit is minimal and you don't have to purchase the shielded, twisted 18g wire to run between the two chargers.

shkvalu | 4 août 2017

Knowing what is available will answer the first question you need to ask. From there it all depends on what you want based off of what you have.

There's a couple of other threads here that go over multiple options, regarding budget and available power. It is a dance and there is really no wrong way of doing it as long as it works for you. It's easy to over buy and its easy to be too cheap and need to go back. From an electrical point of view, getting power from point A to B is going to be the only real variable in price. Everything else will be options of the building codes and the installer. EMT vs Romex, fused disconnect vs no disconnect. Type and size of breakers. Literally the price of copper that day depending on how much (how far) you have to go. The larger you go the more you can handle the more it costs, but also has to be available. The questions get more detailed and the previous answers come into play more. Once you are dialed it's all good. Good luck