Tesla Wall Chargers with 2 Teslas - Advice Needed

[GateFather]

When my wife and I built our house 2020 we knew we eventually wanted to get a second tesla. At the time we had a model 3 (still do) and a minivan. We had the builder put in a 100amp subpanel off our main electrical box right near the garage in the basement, and ran a wire rated for 60amps from that sub panel to the wall charger right above it into the garage. The Tesla Wall charger I have is from 2018 and is a Gen2 unit. Does anyone know if I can power share between a Gen2 Wall Charger and a Gen3 Wall Charger like is seen between Gen2 units here? Load Sharing - TESLA Wall Connector

We are trading our minivan in for a 7-seater Model Y this coming Saturday. I purchased a new Gen3 Tesla Wall charger. My thought is to put another 60amp breaker and wire run out of the sub-panel to this new second wall charger in the garage. Then, set the charge limit to 40amps on both. This ensures that if both vehicles are charging fully, the most draw they will have is 80amps, which is still 20% of the 100amp breaker in the main panel which the sub-panel comes off of. Each car can technically charge at 48amps if the other is not charging since each will have a 60amp rated line and breaker in the sub-panel. So, if we need that extra little speed burst, I could change it to 48amps - but I doubt it'll ever be needed.

Does this sound like a good plan? Am I missing something that would simplify this in some way? Thanks!

 

[zoomer0056]

Human error and forgetfulness is what the breaker wiil protect you from in this case. I don’t know if it's good to be charging both cars at the same time at 48amps each through a 100amp breaker. If it's not good, the 100amp breaker will pop. I think you have to assume you'll forget to dial down the amps at least once.

One more little nit. It's a wall connector. The charger is in the car.

 

[ATPMSD]

Sounds like a good plan to me. A clarification, you will set each connector to a 50A circuit so it will charge at 40A. This is how the Gen 3 works, not 100% on the configuration for the Gen 2. If you find you use one car more, you can set it’s connector to a 60A circuit (48A charge rate) and the other to 40A (32A charge rate), this totals an 80A combined charge rate.

If in the future you opt to get another Gen 3 unit you can easily enable power sharing.

 

[stkgator]

Since you already have a wall charger, I would suggest that you keep it at 60-amps and mount it so it can reach both vehicles. Then use a mobile charger for one of the vehicles for day-to-day charging. This way you, when you really need it, have a faster way to charge your vehicles with the 60-amp service.

This is my setup.

 

[GateFather]

Human error and forgetfulness is what the breakers protect us from. I dont know if it's good to be charging both cars at the same time at 48amps each through a 100amp breaker. If it's not good, the breaker will pop. I think you have to assume this will happen.

One more little nit. It's a wall connector. The charger is in the car.

I was originally planning to just keep them on 40amp max - so they would never charge at 48amp at the same time. Only changing to 48amp in a pinch, but likely wouldn't ever move it from 40amp. However, I did just find that the Gen2 connectors can power share. Load Sharing - TESLA Wall Connector

Sounds like a good plan to me. A clarification, you will set each connector to a 50A circuit so it will charge at 40A. This is how the Gen 3 works, not 100% on the configuration for the Gen 2. If you find you use one car more, you can set it’s connector to a 60A circuit (48A charge rate) and the other to 40A (32A charge rate), this totals a 80A combined charge rate.

If in the future you op to get another Gen 3 unit you can easily enable power sharing.

See above - looks like gen2 connectors can power share. I think I wouldn't need the junction box and can still run 2 60amp breakers with 2 60amp rated wires to each of the wall connectors. Then, install the communications line between them. I just need to confirm whether a gen2 and gen3 can power share. If so, they would intelligently know never to cross the 80amp total threshold and allow one vehicle to charge at max rate possible if the other is not charging, intelligently.

 

[RTPEV]

Are you sure you even need to charge both at the same time? My wife & I have had two EVs since 2013 and other than when we both had LEAFs which needed to be charged every day (and one of which charged at a pitiful 3.3kW), we rarely actually need to plug in both cars the same night. We just alternate which one we plug in. Works well. Full disclosure: I do have a J1772 station that is capable of charging 2 cars at once, but like I said, we almost never use that capability, and in fact, are switching to a single wall connector.

 

[ATPMSD]

looks like gen2 connectors can power share

A Gen 2 can only power share with another Gen 2.

 

[GateFather]

Are you sure you even need to charge both at the same time? My wife & I have had two EVs since 2013 and other than when we both had LEAFs which needed to be charged every day (and one of which charged at a pitiful 3.3kW), we rarely actually need to plug in both cars the same night. We just alternate which one we plug in. Works well. Full disclosure: I do have a J1772 station that is capable of charging 2 cars at once, but like I said, we almost never use that capability, and in fact, are switching to a single wall connector.

I can definitely see this being a bit of overkill, but there is a certain level of convenience to just pulling the car in, and plugging it in with an available plug, knowing the next time you use it, it'll likely be ready to go. Having both vehicles charged to their 80% or so daily limit every morning would be nice, but to your point, likely not necessary at all. I already purchased the Gen3 charger, and really just like the idea of having dedicated plug for each in the garage, ready to go. On another note, I found this really cool charger cable management kit for a good price so going to try to set it up like this for the right side of the garage: EscapeSpeed - Etsy

 

[jjrandorin]

Does anyone know if I can power share between a Gen2 Wall Charger and a Gen3 Wall Charger like is seen between Gen2 units here

The answer to this question is "No, Gen 2 and Gen 3 wall connectors do not power share between each other". If I were in your shoes ( and I was, in Feb / March of 2022 when we sold my wifes BMW X3 and bought a model Y to go with my model 3), I would hunt down a Gen 2 wall connector and power share between the two of them.

Thats what I did.

If you do that, you dont need to do anything different with the car charging. Gen 2 wall connectors dont need their own individual breakers either, you can use a polaris connector to split the electrical connection and that is supported by the install manual (vs gen 3 which specifically calls out you need a breaker per unit).

Necessary? Not at all. Convenient? Yes. I have one car set to charge at 3am in the morning, the other one at 4am and they generally dont overlap but if they do, the charge rate automatically dials down to 24amps for both cars when they charge, then speeds back up, automatically, when one gets done.

 

[GateFather]

A Gen 2 can only power share with another Gen 2.

Ah bummer - looks like I will just have both set to 40amps going into 60amp rated lines and breakers. Mostly they charge overnight so not too concerned with the minor dip in miles charged per hour going from 48 to 40amps.

 

[GateFather]

The answer to this question is "No, Gen 2 and Gen 3 wall connectors do not power share between each other". If I were in your shoes ( and I was, in Feb / March of 2022 when we sold my wifes BMW X3 and bought a model Y to go with my model 3), I would hunt down a Gen 2 wall connector and power share between the two of them.

Thats what I did.

Ah you are right - I just ordered the Gen3 last night and it is still in "ordered" status. Going to see if I can cancel and find a Gen2 somewhere instead.

 

[ATPMSD]

I would hunt down a Gen 2 wall connector and power share between the two of them.

Counter point: he would be buying an old unit and technology. I suggest the savings is not worth it, especially as the power sharing, in this case, does not appear to be a need to have. IHMO it is better to get a new Gen 3 and down the road, get a second one if it is really needed.

 

[GateFather]

Counter point: he would be buying an old unit and technology. I suggest the savings is not worth it, especially as the power sharing, in this case, does not appear to be a need to have. IHMO it is better to get a new Gen 3 and down the road, get a second one if it is really needed.

What does the Gen3 unit do other than OTA software updates, that the Gen2 does not do? After all, they are just plug and charge units, no?

 

[GateFather]

Counter point: he would be buying an old unit and technology. I suggest the savings is not worth it, especially as the power sharing, in this case, does not appear to be a need to have. IHMO it is better to get a new Gen 3 and down the road, get a second one if it is really needed.

Looks like even though I placed the order around 11pm ET last night - there is no option for me to cancel it on the order page for the item. I sent them an email requesting to cancel, and got a response that it could take up to 5 days for them to see it lol. So, I may be getting the Gen3 and just hooking it up as a separate connector on a 60amp rated line, set to 40amp max draw, after all.

 

[jjrandorin]

Counter point: he would be buying an old unit and technology. I suggest the savings is not worth it, especially as the power sharing, in this case, does not appear to be a need to have. IHMO it is better to get a new Gen 3 and down the road, get a second one if it is really needed.

There are a LOT of us who think the Gen2 wall connector is a superior unit. The only thing that is superior about the Gen 3 wall connector is that its wifi connected, and can be locked software wise to a few vins. Everything else about the Gen 2 is better, at least to me.

1. Thicker Cable
2. Max charge rate of 80amp, meaning that at 48amp its barely running at 1/2 its rated capacity, vs a gen 3 which is rated for 48amp so is running at its max capacity.
3. Communication wire (physical connection) for power sharing setup, not depending on a wireless connection to set this up.
4. Physically more sturdy unit
5. Earlier Gen 3 units had an overheating problem. Seems to be fixed, but all the issues people had with them turned me off on them, personally.

I found a new in box gen 2 and actually paid a premium for it over the gen 3, so I definitely put my money where this opinion is.

 

[ATPMSD]

Looks like even though I placed the order around 11pm ET last night - there is no option for me to cancel it on the order page for the item. I sent them an email requesting to cancel, and got a response that it could take up to 5 days for them to see it lol. So, I may be getting the Gen3 and just hooking it up as a separate connector on a 60amp rated line, set to 40amp max draw, after all.

You can return the unit if you feel the Gen 2 better meets your needs:

Tesla Shop

Vehicle accessories, Tesla merchandise and select spare parts are available for purchase from the Tesla Shop.

www.tesla.com

 

[GateFather]

You can return the unit if you feel the Gen 2 better meets your needs:

Tesla Shop

Vehicle accessories, Tesla merchandise and select spare parts are available for purchase from the Tesla Shop.

www.tesla.com

Ah - thanks for linking that. I'd prefer not to go through the hassle of returning, but I'll see what happens.

 

[GateFather]

Customer service came back and said they cannot cancel, and I can return if I'd like. Will have to think about how important the power sharing is vs just setting up 2 independent 40amp runs.

 

[Ostrichsak]

There are a LOT of us who think the Gen2 wall connector is a superior unit. The only thing that is superior about the Gen 3 wall connector is that its wifi connected, and can be locked software wise to a few vins. Everything else about the Gen 2 is better, at least to me.

1. Thicker Cable
2. Max charge rate of 80amp, meaning that at 48amp its barely running at 1/2 its rated capacity, vs a gen 3 which is rated for 48amp so is running at its max capacity.
3. Communication wire (physical connection) for power sharing setup, not depending on a wireless connection to set this up.
4. Physically more sturdy unit
5. Earlier Gen 3 units had an overheating problem. Seems to be fixed, but all the issues people had with them turned me off on them, personally.

I found a new in box gen 2 and actually paid a premium for it over the gen 3, so I definitely put my money where this opinion is.

I came here to echo this so I'll just quote it as it's the best advice in this thread, IMO.

 

[RTPEV]

Ah bummer - looks like I will just have both set to 40amps going into 60amp rated lines and breakers. Mostly they charge overnight so not too concerned with the minor dip in miles charged per hour going from 48 to 40amps.

Back to my own personal experience...I think 40A is certainly sufficient. Especially if, as you say, you are going to pretty much keep them plugged in all the time.

My regimen is to only plug in when the range falls below 100 miles (~30%) and charge to 80% (unless preparing for a trip). My current EVSE is only 30A, and that 50% charge usually completes in less than 6 hours.

If you are plugging in every day and replenishing your daily use, 40A charging will only take an hour or two. Definitely don't worry about "losing" the additional 8A unless your daily needs are extreme.