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Existing Powerwall 2s to get 50% power capacity increase with SW update?

h2ofun

Active Member
Aug 11, 2020
3,107
685
auburn, ca
Actually, what you put about how you had a 125A installed during inspection but then you swapped out 150A after the inspector left was the exact thing that PG&E told me that "shady" solar companies do all the time. He said shady companies cut corners and do stupid stuff behind inspectors backs because they only want to make a quick buck.

It's why he took it as a personal mission to stop my installation. He said Sunrun was shady, and would make my house unsafe. So he was "protecting me" since solar companies don't have the interest of the homeowner in mind. Of course, PG&E only has my best interest in mind... yep. But your story kind of reinforces why PG&E didn't trust me. They thought Sunrun would do what Tesla did for you; and make my MSP "unsafe". And since my MSP was near my gas riser, that's just a big BOOOOOOM waiting to happen.

And it wasn't just him that had the issue. Some (not all) of the folks at the PG&E planning department in their Diablo office also said the same thing. They felt the larger busbar in the solar-ready panels was inherently less safe. So solar companies using like-for-like to add bigger busbars is not allowed per the Greenbook due to safety concerns.
I just cannot believe anyone would do this. Meaning, if there was a fire or something, my guess is when insurance found this out, they would not cover.

And when one goes to sell, if this was not disclosed, law suit potential!

My installers took pictures of EVERYTHING! So if I or anyone else changed anything, then no warranty!

I had to put a 125amp in place of my 200 amp breaker when I put solar in, But with the battery install, and the GW being 200amps, they were legally able to put the 200 amp breaker back in my MSP.
 

holeydonut

Active Member
Supporting Member
Jun 27, 2020
2,371
1,709
East Bay NorCal
Should I be worried about the installation now? Or is this a case of the installer having only permitted back in Dec ‘19 for interior home backup and then they sneakily switched it to whole home backup without redoing the permit??


I don't think you need to be worried - but if you have a copy of the permit or an approval package from your installer you can look to see what they put in the line diagram that your county thinks was installed.

If you see 150A in there, then your installer just did a mini little hack just because they wanted to get approval before they got your 150A breaker. Why they didn't just wait until after your 150A breaker was in hand for inspection is kind of weird. The motive here is just trying to save a few bucks on having the inspector rescheduled.

PG&E's accusation is that a solar company will put 125A on the actual permit and line diagram to get things approved and cleared. Then when nobody is looking the solar company whams a much larger breaker in to save money since they would skip doing the work to allow the proper upgrade. The motive here is kind of malicious because the installer doesn't want to pay for a main service panel or service upgrade.
 
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Reactions: warriorsfan
I don't think you need to be worried - but if you have a copy of the permit or an approval package from your installer you can look to see what they put in the line diagram that your county thinks was installed.

If you see 150A in there, then your installer just did a mini little hack just because they wanted to get approval before they got your 150A breaker. Why they didn't just wait until after your 150A breaker was in hand for inspection is kind of weird. The motive here is just trying to save a few bucks on having the inspector rescheduled.

PG&E's accusation is that a solar company will put 125A on the actual permit and line diagram to get things approved and cleared. Then when nobody is looking the solar company whams a much larger breaker in to save money since they would skip doing the work to allow the proper upgrade. The motive here is kind of malicious because the installer doesn't want to pay for a main service panel or service upgrade.
ok so I had done a main panel upgrade from 200A/100A bus bar to 200A/225A busbar. Still the same 200A service. Not sure how the installer and the subcontracted electrician pulled it off 😀.
Also, regarding the 125A-> 150A breaker, the installer claims it was taking time to order it. But yeah who knows. I did not get a copy of permit nor project plans though. Installer not very transparent on this.
 

h2ofun

Active Member
Aug 11, 2020
3,107
685
auburn, ca
ok so I had done a main panel upgrade from 200A/100A bus bar to 200A/225A busbar. Still the same 200A service. Not sure how the installer and the subcontracted electrician pulled it off 😀.
Also, regarding the 125A-> 150A breaker, the installer claims it was taking time to order it. But yeah who knows. I did not get a copy of permit nor project plans though. Installer not very transparent on this.
I can get details of permits pulled on my house on line.

I would demand copies of plans, and proof the inspector and plans approved a 150A breaker
 
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The four Powerwalls I had installed in March are version 2.1, but the associated breakers are only 30A and they're only wired with 10-gauge wire.

But since I have four of them, does it really matter? Even under the old specs, four Powerwalls can provide 20kW continuous / 30 kW peak, which is significantly more than I've ever seen my house consume. Is there a compelling reason in my case to try to get Tesla back out to upgrade the breakers and wiring?
Hi @ScottRiqui, did you get the 3012170 models?
 

gati2

Member
Jun 19, 2021
10
1
PA
As I'm still waiting for my powerwalls to come in, I'm wondering if it is worth installing breakers/wiring to support the 50% power increase (Existing Powerwall 2s to get 50% power capacity increase with SW update... )?

On one hand, assuming the cost isn't that high, it seems like it would make sense to future proof it a little. Other than cost, are there other things to consider?

Has anyone actually had the software update enabled and is getting the higher power?
 
Last edited:

Vines

Active Member
Jul 20, 2018
2,191
2,678
Silicon Valley, CA
As I'm still waiting for my powerwalls to come in, I'm wondering if it is worth installing breakers/wiring to support the 50% power increase (https://teslamotorsclub.com/tmc/thr...wer-capacity-increase-with-sw-update.226459)?

On one hand, assuming the cost isn't that high, it seems like it would make sense to future proof it a little. Other than cost, are there other things to consider?

Has anyone actually had the software update enabled and is getting the higher power?

The power increase is only for the momentary surge capabilities, to enable motor starting more easily for AC units, pumps, Etc.

Powerwall 2.1 AC will not to my knowledge get a bump to its continuous output. If you upsize wires, you likely will be upsizing them for other reasons, like a long run or a fill deration in a conduit. It is not appropriate to upsize the breaker.
 

h2ofun

Active Member
Aug 11, 2020
3,107
685
auburn, ca
The power increase is only for the momentary surge capabilities, to enable motor starting more easily for AC units, pumps, Etc.

Powerwall 2.1 AC will not to my knowledge get a bump to its continuous output. If you upsize wires, you likely will be upsizing them for other reasons, like a long run or a fill deration in a conduit. It is not appropriate to upsize the breaker.
I was told if one upsized breaker, tesla would say install not supported. And yep, folks just do not understand what is being talked about.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
11,569
13,504
Riverside Co. CA
As I'm still waiting for my powerwalls to come in, I'm wondering if it is worth installing breakers/wiring to support the 50% power increase (Existing Powerwall 2s to get 50% power capacity increase with SW update... )?

On one hand, assuming the cost isn't that high, it seems like it would make sense to future proof it a little. Other than cost, are there other things to consider?

Has anyone actually had the software update enabled and is getting the higher power?

I moved this post into the existing thread (which it appears you were already aware of, as you quoted it in your post), because its the same discussion.
 
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gati2

Member
Jun 19, 2021
10
1
PA
The power increase is only for the momentary surge capabilities, to enable motor starting more easily for AC units, pumps, Etc.

Powerwall 2.1 AC will not to my knowledge get a bump to its continuous output.

According to the original article, the tweet from Musk said:
Powerwall 2 peak and steady power capability is better than advertised. Now that we have lots of operational data, Tesla can unlock higher capabilities for free via software update next month. Depending on production date, power increase power may be >50% at 30C ambient temp.

So my question is has this been unlocked for anyone? In particular, it seems that unlocking a 50% power increase could be problematic because of the wiring / breakers currently in place.

If I am misinterpreting the tweet, I'd appreciate any feedback.
 
Last edited:

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
11,569
13,504
Riverside Co. CA
According to the original article, the tweet from Musk said:


So my question is has this been unlocked for anyone? In particular, it seems that unlocking a 50% power increase could be problematic because of the wiring / breakers currently in place.

If I am misinterpreting the tweet, I'd appreciate any feedback.


No one here has reported any firmware update that does anything of this sort that I have seen. I dont profess to see "everything" that people post here, but I do read here a lot, and dont remember anyone posting anything around it. It would have been pretty big news if someone had received any update that did anything like this.
 

holeydonut

Active Member
Supporting Member
Jun 27, 2020
2,371
1,709
East Bay NorCal
No one here has reported any firmware update that does anything of this sort that I have seen. I dont profess to see "everything" that people post here, but I do read here a lot, and dont remember anyone posting anything around it. It would have been pretty big news if someone had received any update that did anything like this.


You're saying one of Elon's tweets didn't translate to reality?
 

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,564
2,615
Northern California
In particular, it seems that unlocking a 50% power increase could be problematic because of the wiring / breakers currently in place.
Why? If the circuit and breakers, when connected directly to the panel, could handle that instantaneous load, why would moving them to the Tesla device (unless they changed the breaker) be a problem? The problem would be in the Tesla device, which EM claims they underrated.
 

wwhitney

Active Member
Nov 2, 2017
1,019
1,384
Berkeley, CA
A breaker's trip curve is a region on a current vs time graph that shows where a breaker may trip when tested under standard conditions. One side of the region shows the fastest the breaker is allowed to trip; the other side shows the slowest it is allowed to trip. So for example, when the current is twice the breaker rating, one trip curve I pulled up shows that the breaker may take anywhere from 25 to 100 seconds to trip.

The breaker's job is to protect the conductors. A conductor will have a withstand curve, which shows for any given current how long the conductor can carry that under standard conditions before the conductor may get hot enough to damage its insulation. So each conductor gets protected by a breaker whose trip curve time (slowest side) is less that the conductor's withstand curve at any current (well, up to some limit; at crazy high currents, a breaker may still take one full AC cycle (66 ms) to trip, so I imagine the conductor could still be damaged.)

Rather than keeping track of all this information, a conductor gets a single rating based on the current it can carry continuously (for arbitrarily long times), called its ampacity. And a breaker's rating is the current it's supposed to carry continuously without tripping, under the standard test conditions of a single breaker in free air with no enclosure and at a standard temperature (I think 40C). When breakers are used used tightly packed inside an enclosure, which is not free air, a continuous load requires a breaker rated at least 125% of the load current to avoid undesired tripping.

The original Powerwall specs already indicated a maximum continuous output current of 24A, which is the most allowed by the specified 30A breaker it is to be connected to. So no after the fact software revision is going to increase that 24A continuous output current; doing that would necessitate increasing the breaker size and likely the conductors from the breaker to Powerwall However, the Powerwall's peak (10s) rating was much less than what a 30A breaker is supposed to allow for a 10s overcurrent. [At least 120A for the trip curve I was looking at, which may not be the appropriate curve to use for these questions; I believe the UL standard for circuit breakers specifies a trip curve.]

So a software revision could allow the Powerwall inverter to boost its power output for short durations while still remaining within the envelope of what a 30A breaker will handle without tripping. That is the only reasonable thing the tweet could be referring to.

Cheers, Wayne
 

Vines

Active Member
Jul 20, 2018
2,191
2,678
Silicon Valley, CA
Why? If the circuit and breakers, when connected directly to the panel, could handle that instantaneous load, why would moving them to the Tesla device (unless they changed the breaker) be a problem? The problem would be in the Tesla device, which EM claims they underrated.
Electrical inverters have a rating, which determines the breaker and wire size.

If you allow the inverter to output more continuous current, you have to increase its rating and therefore the NEC code required wire and breaker sizes between the Powerwall and the subpanel must increase. Also all the interconnection agreements with utilities may need to be updated based on the new power.

Even if the inverter is capable of more power, it would be a violation and a fire risk to OTA update existing Powerwalls with more continuous power.
 

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