Charging two Teslas at once?

[brkaus]

@jthompson I currently have a single Gen2 WC on a 50a circuit. My plan is to put a junction box just ahead of the current WC and use Polaris connectors to split the wire (example: Not necessarily the correct size - Polaris 6-14 AWG and 6-14 AWG Bagged Insulated Connector, Grey-IPLG6-3B - The Home Depot).

Then I'll run the wire over to the other WC in conduit and include the appropriately rated control wire in the same conduit.

I was going to replace the current disconnect with a small sub-panel, but there isn't a neutral. It would work fine for 240v loads but might confuse someone in the future (or the inspector).

 

[Big Earl]

@jthompson I currently have a single Gen2 WC on a 50a circuit. My plan is to put a junction box just ahead of the current WC and use Polaris connectors to split the wire (example: Not necessarily the correct size - Polaris 6-14 AWG and 6-14 AWG Bagged Insulated Connector, Grey-IPLG6-3B - The Home Depot).

Then I'll run the wire over to the other WC in conduit and include the appropriately rated control wire in the same conduit.

I was going to replace the current disconnect with a small sub-panel, but there isn't a neutral. It would work fine for 240v loads but might confuse someone in the future (or the inspector).

Good recommendation on the Polaris connectors. That’s what we used.

 

[tga]

As shown in post #113 above, when we had our three wall connectors installed, they added a 100 amp breaker in the garage subpanel that leads to a smaller wall connector-only subpanel.

In addition to the Polaris connectors already mentioned, you could run 3 runs from the garage subpanel direct to the wall connectors (ie, the additional wall connector subpanel isn't explicitly necessary). But depending on the length of the runs, it's often cheaper to install a single feeder to a subpanel and 3 short stub runs to the WC's/

 

[jthompson]

@jthompson I currently have a single Gen2 WC on a 50a circuit. My plan is to put a junction box just ahead of the current WC and use Polaris connectors to split the wire (example: Not necessarily the correct size - Polaris 6-14 AWG and 6-14 AWG Bagged Insulated Connector, Grey-IPLG6-3B - The Home Depot).

Then I'll run the wire over to the other WC in conduit and include the appropriately rated control wire in the same conduit.

I was going to replace the current disconnect with a small sub-panel, but there isn't a neutral. It would work fine for 240v loads but might confuse someone in the future (or the inspector).

Thank you for your suggestion!

 

[Rocky_H]

I have a 2012 P85 (dual charger, 80 amp) and 2017 X100D (72 amp charger), and I have been using a single HPWC with 100 AMP service

Except I doubt these suggestions will be usable by you if your wall connector is as old as your original car. The dynamic circuit sharing was not added until the 2nd generation of wall connector, and I think yours is probably a 1st generation one. Here's how to tell the difference: Does your wall connector have a little cutout "dock" in the right side of the body of it where you can hang the charging handle? That was also a feature added in the 2nd gen version, so you can tell.

And yeah, the words "daisy chain" are a little confusing on that. The power lines don't go sequentially in and then out of the wall connector units. They can share a main line for most of the wiring run distance, but that does need to be split a little bit before so it can put a power line into each wall connector.

 

[jthompson]

Except I doubt these suggestions will be usable by you if your wall connector is as old as your original car. The dynamic circuit sharing was not added until the 2nd generation of wall connector, and I think yours is probably a 1st generation one. Here's how to tell the difference: Does your wall connector have a little cutout "dock" in the right side of the body of it where you can hang the charging handle? That was also a feature added in the 2nd gen version, so you can tell.

And yeah, the words "daisy chain" are a little confusing on that. The power lines don't go sequentially in and then out of the wall connector units. They can share a main line for most of the wiring run distance, but that does need to be split a little bit before so it can put a power line into each wall connector.

Good call!! My original HPWC (80 amp on 100 amp circuit) I had installed in February 2013 (they were on back order when I got my car Dec 2012) I left in my last house. Currently have a Gen 2 HPWC (80 amp on 100 amp circuit), and looking at the Tesla website and reading their manual, I will need Gen 3 chargers in my current house to do the wireless load sharing (once they enable it - their website did not state an estimated date that will happen). I can wait until then, but at least I have a 100 amp line so I will have no problem running two Gen 3 48 amp wall connectors with no issues.

 

[MorrisonHiker]

Good call!! My original HPWC (80 amp on 100 amp circuit) I had installed in February 2013 (they were on back order when I got my car Dec 2012) I left in my last house. Currently have a Gen 2 HPWC (80 amp on 100 amp circuit), and looking at the Tesla website and reading their manual, I will need Gen 3 chargers in my current house to do the wireless load sharing (once they enable it - their website did not state an estimated date that will happen). I can wait until then, but at least I have a 100 amp line so I will have no problem running two Gen 3 48 amp wall connectors with no issues.

If you still want to be able to charge at up to 72 or 80 amps, you might want to consider going with gen 2 wall connectors. If 48 amps is sufficient then the gen 3 wall connectors would work if they ever add load balancing. Once that is enabled, you could charge one car at 48 amps or both simultaneously at 40 amps. Alternatively, you could give up on load balancing and just install each of them on a their own 50 amp circuit and be able to charge each at a maximum of 40 amps.

 

[brkaus]

Personally I’d try to find another gen2. Esp if you have a car that can charge over 48a.

if you do go gen3 and replace what you have you can save some $$ on the wires to to new wall units. No need to support 100a.

The gen3 may not even accept that large of wire on the lugs.

 

[jthompson]

If you still want to be able to charge at up to 72 or 80 amps, you might want to consider going with gen 2 wall connectors. If 48 amps is sufficient then the gen 3 wall connectors would work if they ever add load balancing. Once that is enabled, you could charge one car at 48 amps or both simultaneously at 40 amps. Alternatively, you could give up on load balancing and just install each of them on a their own 50 amp circuit and be able to charge each at a maximum of 40 amps.

Good suggestion! Thank you!!

 

[jthompson]

Personally I’d try to find another gen2. Esp if you have a car that can charge over 48a.

if you do go gen3 and replace what you have you can save some $$ on the wires to to new wall units. No need to support 100a.

The gen3 may not even accept that large of wire on the lugs.

Thanks for the suggestion!!

 

[r1200gs4ok]

I currently have a 2019 M3 and 2020 MS.....I have a 100amp panel......my Gen 2 wall connector is on a separate 50a breaker/circuit......it charges at 40amps......I have a second 50a breaker/circuit and connect it to my cars mobile charger.....it charges at 32amps....

The second 50amp circuit came from the electric dryer we don't use because we have gas.....I disconnected the breaker and capped off the wires in case a new owner wants electric dryer.....hen I ran new 6awg for the Nema 14-50 wall outlet......was thinking of getting new wall charger, but 32amps is good enough for me......I d not want to change the panel out $3500 for a 200amp panel....I think I made right decision for my application.....if need faster charge, I can still run wall charger cable to my MS......

I have heard about lots of problems with the Gen 3's....that why I did what I did

 

[cwerdna]

Except I doubt these suggestions will be usable by you if your wall connector is as old as your original car. The dynamic circuit sharing was not added until the 2nd generation of wall connector, and I think yours is probably a 1st generation one. Here's how to tell the difference: Does your wall connector have a little cutout "dock" in the right side of the body of it where you can hang the charging handle? That was also a feature added in the 2nd gen version, so you can tell.

And yeah, the words "daisy chain" are a little confusing on that. The power lines don't go sequentially in and then out of the wall connector units. They can share a main line for most of the wiring run distance, but that does need to be split a little bit before so it can put a power line into each wall connector.

On this note, bottom of Second Generation Wall Connector mentions how to tell first gen vs. second gen via the part number. My work had some of the first gen ending in -C or -D in one building and some really old ones (probably -A or -B) under another building which had compat problems w/newer Teslas (there's already at least one thread on that).

The -C or -D ones got replaced with 2nd gens so that we could have load sharing. We had 5 100 amp circuits and ended up having 2 gen 2 WCs on each 100 amp circuit via load sharing. Not only does there need to be the split power for each WC sharing a circuit, you need to connect communication wires between them (page 30 and 31 of the manual).

Eventually the really old ones under the other building got replaced with gen 2's (gen 3 didn't exist yet) as that was the only solution to the compatibility problems.