Load-sharing home setup

[EarlyAdptr]

I've been struggling with I think what you're stuggling with too - flexibility and ability to charge two vehicles. I"m also a newbie at all of this.

I've decided to go hardwired - reducing my future flexibility. The main reason, is with hard wired I can connect to a 60amp circuit breaker and run 48amps to the charger (maxing it out). If I used a NEMA plug I would max out at 40amps. So if I'm charging two vehicles, I can get more juice (load balancing).

The other benefit, with a NEMA 14-50 plug you have to use a GFIC 50a circuit breaker. My understanding is those are expensive now, and there's some reported issues of "tripping" although I don't know if that's a real issue or not.

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[chrismc]

The GFCI breaker requirement for a 14-50 receptacle should not be underestimated. I just priced out my wiring and a 60A non-GFCI breaker is $20 while a 50A GFCI one was over $200. Also, the GFCI breakers are pretty hard to find right now so a lot of people are adding a 50A spa sub panel in-line to the receptacle to get the GFCI protection. Even upsizing the wire for a 60A circuit, going the hardwired route was MUCH cheaper in my quote (plus I get faster charging).

 

[Gshenderson]

I've been struggling with I think what you're stuggling with too - flexibility and ability to charge two vehicles. I"m also a newbie at all of this.

I've decided to go hardwired - reducing my future flexibility. The main reason, is with hard wired I can connect to a 60amp circuit breaker and run 48amps to the charger (maxing it out). If I used a NEMA plug I would max out at 40amps. So if I'm charging two vehicles, I can get more juice (load balancing).

The other benefit, with a NEMA 14-50 plug you have to use a GFIC 50a circuit breaker. My understanding is those are expensive now, and there's some reported issues of "tripping" although I don't know if that's a real issue or not.

To me, “flexibility” is really more about how you design and run the circuit vs. whether you choose to put a hardwired EVSE or NEMA 14-50 plug at the end of said circuit. If the circuit is designed for flexibility, you could swap out hardwired EVSE / NEMA 14-50 / or simply have capped wires into a covered junction box in 15 minutes with nothing more than a screwdriver and the appropriately sized breaker.

 

[astonius]

This daisy-chaining idea sounded great in theory, but after reading the guide for Tesla Gen 3 load-sharing it seems each connector still requires a dedicated circuit. It's also not clear if load-sharing works between a Tesla and a non-Tesla (anyone know?).

Do Juicebox or Wallbox support daisy-chaining?

 

[crashmtb]

This daisy-chaining idea sounded great in theory, but after reading the guide for Tesla Gen 3 load-sharing it seems each connector still requires a dedicated circuit. It's also not clear if load-sharing works between a Tesla and a non-Tesla (anyone know?).

Do Juicebox or Wallbox support daisy-chaining?

since @timesinks pointed out NEC now explicitly requires separate circuits if there’s more than one charger… I’d just copy his setup

 

[Rousie13]

This daisy-chaining idea sounded great in theory, but after reading the guide for Tesla Gen 3 load-sharing it seems each connector still requires a dedicated circuit. It's also not clear if load-sharing works between a Tesla and a non-Tesla (anyone know?).

Do Juicebox or Wallbox support daisy-chaining?

Wallbox allows sharing of one circuit between multiple units.

 

[camaroz1985]

We went with the Grizzl-E Duo. I know you said for the cost you would rather go hardwired, but I figured we don't need peak charging speeds for our normal trips and certainly not daily driving, and other load sharing options would have been around $1400 vs $900 for the Duo (plus the cost of running another 50-60A circuit to the other side of the garage). So far it has been working great with our Volt and newly acquired ID.4. The Volt will eventually be replaced by the R1T.

 

[astonius]

We went with the Grizzl-E Duo. I know you said for the cost you would rather go hardwired, but I figured we don't need peak charging speeds for our normal trips and certainly not daily driving, and other load sharing options would have been around $1400 vs $900 for the Duo (plus the cost of running another 50-60A circuit to the other side of the garage). So far it has been working great with our Volt and newly acquired ID.4. The Volt will eventually be replaced by the R1T.

The more I think about it the more this is becoming an option. My only concern is it doesn't appear to be a "smart" connector where I could manage the time and split of power between the two vehicles remotely. I would really like to have granular control over when the cars get full power and which car is prioritized.

 

[camaroz1985]

The more I think about it the more this is becoming an option. My only concern is it doesn't appear to be a "smart" connector where I could manage the time and split of power between the two vehicles remotely. I would really like to have granular control over when the cars get full power and which car is prioritized.

I have found it is best to leave the smart part to the things that are already “smart” in this case the cars. Right now I have them both set to charge immediately upon plugging in. They both get 20A allocated (even though the Volt can’t use it). When one vehicle is done it keeps 8A for future conditioning, preheating/cooling, etc. and the remaining charging vehicle gets 32A.

 

[Rousie13]

With the Wallbox units it will typically split the power evenly if both vehicles need charging….in my case 20A per vehicle. If only one vehicle needs charging then it will send the full 40A to that vehicle and the other vehicle will be in a “waiting” status.

 

[astonius]

Just an update: I've landed on a single 60A circuit from my 90A sub-panel feeding a new sub-panel with 2x 60A breakers feeding 2x EVSEs. My electrician said the cost difference won't be much.

Now the only remaining question is which EVSEs to get. I was originally sold on getting Tesla Gen 3s and using a Lectron adapter for the R1T, which is still an option, but I'm also considering the Wallbox Pulsar Plus 48 and adapting the Tesla. I like the aesthetic, lower price, and lack of comm wire required for the Tesla units, but I like the scheduling and consumption information provided by the Wallbox. If I knew the Tesla units would have those features in a future OTA update this would be a no-brainer, but there doesn't seem to be any indication those features are coming. I'd appreciate any recommendations!

 

[Rousie13]

Just an update: I've landed on a single 60A circuit from my 90A sub-panel feeding a new sub-panel with 2x 60A breakers feeding 2x EVSEs. My electrician said the cost difference won't be much.

Now the only remaining question is which EVSEs to get. I was originally sold on getting Tesla Gen 3s and using a Lectron adapter for the R1T, which is still an option, but I'm also considering the Wallbox Pulsar Plus 48 and adapting the Tesla. I like the aesthetic, lower price, and lack of comm wire required for the Tesla units, but I like the scheduling and consumption information provided by the Wallbox. If I knew the Tesla units would have those features in a future OTA update this would be a no-brainer, but there doesn't seem to be any indication those features are coming. I'd appreciate any recommendations!

We have a pair of 40A Wallbox units on a 50A circuit and I've been VERY happy with them. They continuously update the app and the information that is provided via the app/website is very very detailed. When we first set them up, we had an issue where the units kept dropping the load sharing about once a week.....a few members of a Volvo forum I'm on had the same issue with their setup. I contacted Wallbox support and they got their engineering team involved. They regularly updated me on the process of the software updates after they determined it was a software issue. They pushed the update out and followed up/monitored my data to make sure everything was good. It's been months since that issue and they have been rock solid since then.

 

[NY_Rob]

I'm also considering the Wallbox Pulsar Plus 48 and adapting the Tesla.

Before pulling the trigger, I suggest you check with your power utility as some are offering $500+ direct rebates if you purchase an approved model. Last year I got $500 back from my power co. when I purchased a JuiceBox Pro 40 for $550.

 

[astonius]

Before pulling the trigger, I suggest you check with your power utility as some are offering $500+ direct rebates if you purchase an approved model. Last year I got $500 back from my power co. when I purchased a JuiceBox Pro 40 for $550.

Good call, I actually did check in with my utility company. They are great, but they don't offer much in the way of EVSE rebates, only a $50 credit for any related expenses.

 

[astonius]

Update!

I landed on the Wallbox Pulsar Plus 48A units. I purchased two of them directly from Wallbox. They were not cheap, but at least I was able to skip sales tax by buying directly. My electrician was booked up for a few weeks, and I delayed scheduling until after my R1T was delivered.

Today was install day, and it couldn't have come too soon. We were getting by the past two weeks with 110v charging overnight, but it was painfully slow, at times adding 1 mile or less per hour. I suspect the heat is playing a role here as the fans were running consistently to manage battery temp. Thankfully we have a very short commute to my daughter's daycare and work from home otherwise, but I am so glad to have a more viable option now.

I did go the load-sharing route with 48 amps of total power available to both units. My house is roughly 3500 sq ft with 200A total service, so I tried to find a balance that could support 2 EVs effectively without overloading the panel and be managed smartly and remotely. We had to move some existing circuits around to make room for a new 60A circuit which feeds a sub-panel with two additional 60A breakers, one for each individual Wallbox. We also ran a CAT6 cable between the two Wallboxes to manage communication for load-sharing.

Installation took around 2.5 hours. This included cutting drywall to run the cables and recess the sub-panel. Wallbox oddly does not include load-sharing instructions in the box, and the instructions on their website are broadly applicable to a wide range of their products. I found this YouTube video incredibly helpful in configuring and wiring the CAT6 between the two units. Basically you set the primary unit's charging speed setting to "8", the secondary to "0", run one wire from slot 1 on the primary to slot 1 on the secondary and another wire from slot 4 on the primary to slot 3 on the secondary. Once the units are powered install the latest software updates, then after restart configure the load sharing through the app on the primary unit.

I plugged in the primary first and watched the truck ramp to 48A in a matter of seconds, adding ~24 miles of range per hour. I then did the same with the secondary and saw the same behavior. I don't have two EVs to test the sharing capabilities fully, but I was happy to see both delivering the peak 48A independently.

Quick review of the Wallboxes: I like them overall, but there are a few concerns. Appearance-wise they are very sleek and small compared to other units like Juicebox, Tesla, or even Rivian. The cable is flexible and plenty long at 25 ft. The charging handle feels solid, although it immediately showed wear from brief and light contact with my garage floor. The installation guide was straightforward and easy to follow aside from the missing load-sharing details. I do wish they used wifi rather than CAT6 for load-sharing communication, something the Tesla units do for nearly half the price, though once installed this isn't really a concern. The app is not bad, allowing for monitoring and adjustment of the amperage for each unit on-the-fly, but I do wish the scheduling feature was more robust. You can set schedules for charging, but it's a binary system: on or off. I'd like to be able to schedule amperage limits for certain times of the day when I know I'll be using higher amperage appliances such as the oven or dryer to prevent overloading.

Overall I'm very happy with this setup and look forward to having two EVs to take full advantage. I would recommend this option to anyone who wants flexibility and load-sharing capability.

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