Suggestions for "daisy-chained" EV Charger

[isfopkd]

My wife will get her electric car at the end of this year, so I want it to be "daisy-chained" to a second EVSE to allow two cars to be conveniently charged from a single circuit. Any suggestions on which one to purchase?

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[HaulingAss]

My wife will get her electric car at the end of this year, so I want it to be "daisy-chained" to a second EVSE to allow two cars to be conveniently charged from a single circuit. Any suggestions on which one to purchase?

The Tesla Wall Connector is a good one and one of the best values, just be aware that Gen. 2 and Gen 3 cannot be mixed. You need either 2 Gen. 2's or 2 Gen. 3's if you want to power share the same circuit.

If you already have a Gen. 2 Wall Connector there are still a few Gen. 2's available, so I would buy the second one now, without waiting.

 

[Crissa]

The Tesla Wall Connector is a good one and one of the best values, just be aware that Gen. 2 and Gen 3 cannot be mixed. You need either 2 Gen. 2's or 2 Gen. 3's if you want to power share the same circuit.

If you already have a Gen. 2 Wall Connector there are still a few Gen. 2's available, so I would buy the second one now, without waiting.

Yeah, these have programming to be smart enough to split the load, so the circuit is not overloaded.

No daisy-chaining required.

But if you want to daisy chain... Plug a 'granny' cable into the truck and plug the truck into the wall. That'll reduce the truck's charging by whatever level you've set the granny cable to. (At least, this is how Lighting and Rivian power distribution works).

-Crissa

 

[ÆCIII]

Just remember with Gen II daisy-chaining, it requires a second 'communication' data cable, which the wall connectors use to manage load sharing under different conditions and states of charge for each vehicle. Tesla explains the installation aspects of load sharing here:

Load Sharing – Second Generation Wall Connector | Tesla Support

Even though the Gen II requires an extra communication cable ran, I do like the capacity of the Gen II wall connector, up to 72 amps on a 90amp or greater circuit. This current draw is only utilized really for cars like some earlier Model-X's, but I'm also wondering what max current the onboard inverters for AC charging in the Cybertruck will be able to utilize, so I'm watching for those specs closely.

- ÆCIII

 

[HaulingAss]

Yeah, these have programming to be smart enough to split the load, so the circuit is not overloaded.

No daisy-chaining required.

But if you want to daisy chain... Plug a 'granny' cable into the truck and plug the truck into the wall. That'll reduce the truck's charging by whatever level you've set the granny cable to. (At least, this is how Lighting and Rivian power distribution works).

-Crissa

The "daisy chaining" refers to the low voltage communication wires, not the line voltage supply. If the Gen. 3 does that function wirelessly, the term may no longer apply.

 

[Crissa]

The "daisy chaining" refers to the low voltage communication wires, not the line voltage supply. If the Gen. 3 does that function wirelessly, the term may no longer apply.

Splitting load isn't a daisy chain tho?

-Crissa

 

[HaulingAss]

Splitting load isn't a daisy chain tho?

-Crissa

The terminals on the Wall Connector look like they would work with two wires but I don't know if that's the recommended method or not. If so, that would be daisy-chaining. I just assumed the power feed would be split in a junction box and each Wall Connector would be T'ed off that. In my use of the word, that would not be daisy chaining.

Do you know how they are typically wired?

 

[ÆCIII]

Actually the term 'Daisy-Chained' is a somewhat fuzzy or confusing misnomer term when describing the connection of two to four Gen II wall connectors on the same circuit, because in fact their power wires are connected in Parallel via distribution connections in an approved junction box with one main circuit home run from the breaker or load center panel. So the main circuit wires supplying the charge current aren't really 'daisy-chained' at all.

The power terminals of the Wall Connector are large enough to to handle wiring of up to 80 amp to 100 amp circuits. However that does not mean or imply that parallel connections can be done at the wall connector because they are not supposed to per the instructions and probably the National Electric Code (NEC) also. The instructions specifically state that an approved separate junction box for power connections must be used for configurations of more than one wall connector.

However, even though the wires supplying power are connected in Parallel, one Wall Connector of the set must be designated as 'master' or leader, while the others are designated 'followers'. This is done with two parts of the configuration, via the configuration rotary switches, and also the way the Communication cable wires are connected. The master Wall Connector has its rotary switch configured just like a single unit depending on the max current of the circuit breaker. The follower wall connectors have their rotary switch set to position "F" (meaning follower I would guess).

The Communication Cable wires are actually connected in what could be described as a daisy-chain, with designated "IN" and "OUT" terminal pairs. The master will only have wires to it's "OUT" terminals. The first follower will have the other end of the wires from the master connected to it's "IN" terminals, and then repeat from that Wall Connector for up to two more followers if implemented.

The video in the link I posted above in this thread describes all this very well and concise.

- ÆCIII

 

[bwhntr78]

The way the gen 3 wall connectors work on a single circuit requires a sub panel. The wireless communication allows each circuit to have the same max load as the main circuit. i.e. 50 amp breaker on the main panel feeding 2 50 amp breakers on the sub. You then set up the wall connectors based on the max load and they will communicate with each other to share the power until one car finishes charging, then the power output will ramp up for the 2nd car. It works pretty seamlessly and setup was actually pretty simple.

 

[Crissa]

The terminals on the Wall Connector look like they would work with two wires but I don't know if that's the recommended method or not. If so, that would be daisy-chaining. I just assumed the power feed would be split in a junction box and each Wall Connector would be T'ed off that. In my use of the word, that would not be daisy chaining.

Do you know how they are typically wired?

I thought they'd be wired separately to the wall, but if sharing a circuit, then have the network connection.

-Crissa

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