Discussion: Powerwall 3 [Speculation / Discussion etc]

[Jeremy3292]

"For large homes that would like backup power capability for longer periods, Tesla staff say that a Powerwall 3 without an integrated inverter will be offered that can be “daisy-chained” to the hybrid battery unit."

Does this suggest the PW3 without inverter could used for those with existing solar instead of a PW2?

The way I see it there are two options here:

1. Tesla is lying to us in their FAQ page and they will sell it without solar later.
2. Tesla has purposely made the PW3 to only be integrated with solar via hardware, software, or some combination of both.

 

[mongo]

It's possible but I doubt it. It probably requires a master PW3.

That would explain "daisy-chain".
Is your interpretation that it lacks solar inverter but can sink/ source AC power via the battery inverter? Seems like it would need to be useful, with the alternative being DC link to the main unit (also daisy-chain).

 

[MP3Mike]

That would explain "daisy-chain".
Is your interpretation that it lacks solar inverter but can sink/ source AC power via the battery inverter? Seems like it would need to be useful, with the alternative being DC link to the main unit (also daisy-chain).

I don't know, maybe it is literally just an expansion battery and doesn't provide any additional inverter capacity.

 

[Grayson73]

I ordered Tesla Solar a week ago and asked if I could switch to Powerwall 3 if it's available when it's time for installation in Jan/Feb 2024. Tesla Project Advisor responded:

"Powerwall 3 is not going to be available until mid-to-late next year. You will not be able to switch to it."

 

[Jeremy3292]

I ordered Tesla Solar a week ago and asked if I could switch to Powerwall 3 if it's available when it's time for installation in Jan/Feb 2024. Tesla Project Advisor responded:

"Powerwall 3 is not going to be available until mid-to-late next year. You will not be able to switch to it."

This is what I figured as I also have placed an order. They are just doing small trial runs rn to make sure everything works. I figured mass production and availability wouldn’t be until the 2nd half of next year. Not worth the wait IMO. Also we know Tesla and their timelines…

 

[jhn_]

I don't know, maybe it is literally just an expansion battery and doesn't provide any additional inverter capacity.

This is what I would bet on. Essentially a PW3 that they leave so parts out of so they get economy of scale in manufacturing only one box and can retire the PW2. Let’s call it the PW3- .

 

[Vines]

This is what I would bet on. Essentially a PW3 that they leave so parts out of so they get economy of scale in manufacturing only one box and can retire the PW2. Let’s call it the PW3- .

This may be the way of the future, nobody here knows for sure.

I am curious if stacking is a thing of the past though, or if the glass faceplate can come off and there is some way to stack them.

 

[MP3Mike]

I am curious if stacking is a thing of the past though, or if the glass faceplate can come off and there is some way to stack them.

The glass face coming off for stacking doesn't seem likely, as I read somewhere that even the glass faceplate was used for thermal management. (Since PW3 is passively cooled with no fan.) I suspect the design precludes stacking.

 

[Vines]

The glass face coming off for stacking doesn't seem likely, as I read somewhere that even the glass faceplate was used for thermal management. (Since PW3 is passively cooled with no fan.) I suspect the design precludes stacking.

I suspect you are correct that stacking doesn't look likely with that form factor. It was nice to be able to put about 40 kWh in such a small footprint with a stack of 3 units. There should be a way to take up less wall space for the larger installations, but who knows what that may be like.

 

[Silent Ludicrosy]

According to the rumor mill, Cybertruck will have bi-directional charging. If true, I assume it will interface directly with PW3?

https://x.com/matthewdr/status/1709653623976972341?s=46&t=2IHyuGb0eaevgGCCKEOOog

 

[brkaus]

According to the rumor mill, Cybertruck will have bi-directional charging. If true, I assume it will interface directly with PW3?

https://x.com/matthewdr/status/1709653623976972341?s=46&t=2IHyuGb0eaevgGCCKEOOog

Remember that a gateway (islanding) of some sort needs to be added to the house to actually enable use during an outage.

 

[Grayson73]

Remember that a gateway (islanding) of some sort needs to be added to the house to actually enable use during an outage.

My Genesis GV60 has V2L. I can use long extension cord and power strip to power refrigerator, etc. It's limited to 15A, 1800W

 

[Vines]

My Genesis GV60 has V2L. I can use long extension cord and power strip to power refrigerator, etc. It's limited to 15A, 1800W

And someone with a generator outlet could plug their car into that, lockout the main breaker and feed power to the whole home even if the loads are limited. It's a good guess that the blocked off port of the Powerwall 3 would allow expansion or V2G through an additional interface port.

 

[Matt-FL]

V2G in any capacity to provide whole-home backup will require some additional hardware on either the car or the home. EV Cars and motor controls are (presently) designed to pull a long-term low to medium draw from the battery bank. To power a house, it needs to ramp up and down far higher kW than what a car battery typically is designed for. Even the Lightning - with its added inverter hardware option - has a limit of 9.6kw draw with 98 or 131kWh batteries. Compare that with similar kWh in powerwalls (say 8) where you can push 40kw. If you don't need more than 9.6kw aggregate for your house, then you are golden. You have a battery that you can also drive around town. As long as while you are 'around town' your power doesn't go out

I think I'm trying to say that it's not as simple as connecting up an EV as a battery bank, lots of other parts and pieces need to be in place and aligned.

 

[brkaus]

And someone with a generator outlet could plug their car into that, lockout the main breaker and feed power to the whole home even if the loads are limited. It's a good guess that the blocked off port of the Powerwall 3 would allow expansion or V2G through an additional interface port.

Yup. Or you get the folks that don't want to pay an electrician and wire up a nice suicide cord.

 

[MP3Mike]

To power a house, it needs to ramp up and down far higher kW than what a car battery typically is designed for.

The limit has nothing to do with the battery. The battery in an EV supports hundreds of kW that goes up/down way faster than a house would as demands from the drive motor(s) change.

Even the Lightning - with its added inverter hardware option - has a limit of 9.6kw draw with 98 or 131kWh batteries.

That is a limitation of the inverter that Ford put in the F-150 Lightning, it has nothing to do with the battery size.

Compare that with similar kWh in powerwalls (say 8) where you can push 40kw.

Right, you have put together 8 inverters to support that.

 

[mongo]

To power a house, it needs to ramp up and down far higher kW than what a car battery typically is designed for.

The pack charges at 250kW and Plaid launches at 1000 HP or 750kW.
Steady driving is 300Wh/mile @ 60 MPH = 18kw = 75A @ 240 V

 

[Matt-FL]

Yes, hence my suggestion that it is not as easy to enable as just 'plugging in your car'. Many other pieces make this happen.

 

[willow_hiller]

Yes, hence my suggestion that it is not as easy to enable as just 'plugging in your car'. Many other pieces make this happen.

Given we know the PW3 is DC-coupled, is there any reason why it couldn't be as easy as just plugging it in? Of course, the vehicle software would need to support it, but as far as I know, there's no reason why a vehicle battery couldn't act as the DC source for the PW3.

 

[MP3Mike]

Given we know the PW3 is DC-coupled, is there any reason why it couldn't be as easy as just plugging it in?

How many DC-DC couplers does it have? And what voltage are they rated for?

Likely, one for solar panels, which would be one-way. But is there a second one for a car interface that is bi-directional? (Or maybe if there is a second one is a DC-DC chaining port that could go to PW3 batteries or a car.)

This level of details just isn't available at this time.