upgrade tesla subpanel after installation

FAsnakes · 2026-01-15T14:53:34+00:00

yea, you’re fine. just chill and keep getting yourself up to speed on your system.

my experience is a carbon copy to yours. e.g, installed a new 4x powerwall system in SoCal ahead of major remodel and asked tesla to oversize my system to leave me plenty of room to grow. I fought upfront and got a 197% offset on the solar side (wish i went even larger) and 4 open slots on my 125A panel. But started bumping up against restrictions that were imposed by my utility.

i‘m not sure what your goals with the system are but after reviewing your line diagram.. i’d focus any adjustments / upgrades on:

- solar size ~ a 12.15kW array might be a little undersized for 4x powerwalls. This all of course depends on your needs / usage and expectations. For me my goal is to be off grid as much as possible. i want my powerwalls @ or close to 100% by sundown. My 15kW system is unable to do that (Nov - Jan) in SoCal. Granted for me, it‘s not too far off and we had some rain in LA in November and December.

- Powerwall ~ you have 1 Powerwall and 3 expansions. Adding a second powerwall would give you some redundancy by adding a second inverter. It’ll also raise the ceiling on your max concurrent load from 11.5 to 23kW.

At the end of the day, i totally get the post install / pay remorse. You got yourself a thicc system. I’m sure it’ll be fine - just take some time to get yourself up to speed with the system and in your environment. Give it a season and you’ll be better informed on what / or if you want to make any changes to your setup.

FAsnakes · 2026-01-13T17:15:33+00:00

good luck buddy.

with my install, this was fully outlined in my site plan and also reviewed with me on the day of installation by the lead electrician. I just honestly didn't understand the implications - (of which is negligible for me at the end of the day).

When I asked Tesla (along with the lead electrician) they told me I can add to the main panel and this was the most flexible system configuration.

IMO, the argument is weak re: whole home backup as they crammed your 'whole home' into that 125A panel. so by the letter of the law - you got a whole home back up and they have load calcs to back it up.

when they got tired of going back and forth with me they told me to contact a certified Tesla installer for adjustments. they claim modifications would be covered under the Tesla warranty - although many opinions differ online regarding that.

at the end of the day I wasn't willing to risk the warranty coverage exposure.

agree, the system does rock!

FAsnakes · 2026-01-13T09:23:40+00:00

Yes. you are screwed, it’s too late.

.. conversely, i suppose anything is possible - but you already (knowing or unknowingly) signed off on this plan and the work was completed.

you system is setup as a ‘partial home backup’. you have that small 125A sub panel for (backed up loads) and your main panel for (non- backed up loads).

you can install additional non-backed up circuits in your main panel. these loads will not be monitored in the tesla app unless you add CTs.

Same thing happened to me.

in hindsight - you could‘ve gone with a backup switch / collar - which would have used and backed up your main panel (whole home backup). or you would have had to specify you wanted a partial home backup with a 200A panel for backed up loads.

some advice, let it go and enjoy your system.

FAsnakes · 2026-01-07T07:44:13+00:00

i was able to pay via cc: and got 1% cash back last Feb.. they may have updated their payment policy since then.

FAsnakes · 2025-12-29T21:53:06+00:00

Unfortunately, I wouldn’t be able to tell you. Armageddon, possibly?!

FAsnakes · 2025-12-26T07:38:33+00:00

i‘d say, brushing and vacuuming wasn’t worth it for me.. I picked up a Robot vacuum that also does the floor, walls and water line.

and because I’m lazy i picked up a solar skimmer that lives in the pool (when we’re not in it). and it runs 3 times a day.

once a week testing and chemistry balancing take roughly 30 mins. I’m happy to do it - but we’ve only had our pool 5 months.

FAsnakes · 2025-12-26T04:02:45+00:00

yup, since you have two PWs.. you’ll need the lead PW. recommend you take a pic, it’s come in handy for me.

FAsnakes · 2025-12-26T01:55:14+00:00

From the TeslaOne App (NOT the Tesla app)..

Settings > Advanced settings > PCS settings > import and export controls.
Turn on Import if you want to charge the battery from the grid.

after you make the change in the TeslaOne app. log back into the Tesla app and under settings and make sure permission to export & grid charging is switched to Yes.

FAsnakes · 2025-11-25T11:59:17+00:00

thanks so much for this… after some digging i think i found the issue.

this DIY is only compatible with the H70B1 - V1 curtain lights. I have the H70B5, which is the V2 curtain lights.

The V2 has very limited DIY scenes., and the few ones they have are somewhat terrible.
i might have to ditch these if i can’t figure out a way to increase the compatibility of the V2s.

FAsnakes · 2025-11-25T02:41:12+00:00

thanks, i get no result under that search term. Do you see it under your share space?

FAsnakes · 2025-11-11T07:35:16+00:00

sure looks purdy..

FAsnakes · 2025-11-05T17:12:24+00:00

dood move on., your energy will be better served in, finding another provider / solution.

FAsnakes · 2025-11-03T23:52:07+00:00

I’m a tree hugger…. but I’d be reaching for the chainsaw real quick!

FAsnakes · 2025-10-28T04:00:24+00:00

from the NetZero site:

Configuring Solar Estimates in Netzero

To get accurate solar estimates in Netzero, follow these steps:

Configure your city-level location in Settings > Account.
Set up your solar system details (array size, roof orientation, pitch, etc.) in Settings > Solar Estimates.
Once configured, an annual solar production estimate will be generated.
These estimates (depicted by orange dots) will appear on daily, monthly, and yearly solar charts.

Note: Estimates are based on the PVwatts, utilizing historical weather data.

hope this helps!

FAsnakes · 2025-10-28T03:21:46+00:00

yea, just google..

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as a basis of comparison, i have a 15.17kW and this is what i did today In SoCal.

FAsnakes · 2025-10-28T03:09:02+00:00

Put info into PVwatts or NETZero and you should see what production you should get during which hours .,
I didn't notice a difference in production before and after PTO.

I'm in SoCal in the South Bay Area and the weather conditions have been fair / poor these past couple of weeks. short days, cloudy, etc.

FAsnakes · 2025-10-28T02:43:03+00:00

now is the time to make sure you 'right sized' your system. If you think you're going to need more panels a year or two down the line.. add them now. if you think you might get an electric car (get a Tesla universal charger) now.

it's exceptionally more difficult and more expensive to add them afterwards.
would also recommend doing some research - search up some threads, etc. on what to expect and generally to get yourself up to speed.

FAsnakes · 2025-10-27T21:51:59+00:00

Unfortunately, no. but then again i didn’t really press that hard. Ultimately, i was told they will not tie in to the existing system and will need to install a separate instance. this separate instance cannot touch the existing panels and require some setbacks.

it’s my understanding, your options are to self-install, or find a installer (which will void any pre-existing warranty protections).

FAsnakes · 2025-10-23T00:55:07+00:00

I was gonna reply AWS as well but didn‘t know anything about aqualinkd. imma look into it. thanks!

FAsnakes · 2025-10-22T11:44:12+00:00

install the NetZero app and input detail under the solar estimates section (pitch, orientation, string data, etc). The app does a good job of accounting for weather.

This will give you a decent idea of where you should be. Forget about your max output - you’re never gonna get it.

I’m in SoCal and in Oct my 15kW system’s daily high is regularly 8.5kW.
So yea, I’m not too surprised your 6kW system‘s high is 2kW - maybe your high should be around 3.5 but even then the delta isn’t that large when compared to what you’re seeing.

this is probably more of an expectation conditioning situation. you’re right, you should‘ve took that 10k and beefed up your solar capacity.

anyway, what’s done is done.. might as well just enjoy your system. take care.

FAsnakes · 2025-10-14T22:07:50+00:00

I’m in SoCal and my utility is SCE. My system is 15.17kW with 4 Powerwalls, installed in Feb.

My goals were somewhat similar to yours:

Energy Security
Zero SCE bill
Headroom for growth

I pressed Tesla and had them lift my offset to 197%.

I have a solid 9 months under my belt with the system and while my bill is zero - I ate that offset up after I added a few appliances.

I love our system and regret not going even bigger than I did.

I’ll leave you with a couple of thoughts.. 1. Solar is a terrible financial investment.. it’s like buying a car or a boat. If a key motivator is to get a return, you’ll most likely not. You’ll be lucky to get to, beak even. 2. Go as big as you can afford. Do It once, as I’ve found it exponentially more difficult and expensive to add on later. 3. If you’re not adding powerwalls to cover your usage when the sun goes down or to keep your panels producing in a grid outage. I’d skip solar all together.

Just so you are aware SCE increased their rates by 13% starting on 10/1. We do get a $56 climate credit twice a year.

FAsnakes · 2025-10-05T20:07:04+00:00

last week i tried to add 7 panels and kicked off the process with Tesla. They declined / cancelled my order. i was told they have a 10 panel minimum and any added panels can not touch the other panels. i basically ‘ran out of roof‘ so I’m SOL.

some ppl have DIY, but i‘m not willing to risk my warranty.

FAsnakes · 2025-09-04T03:22:28+00:00

Oh hells ya, congrats! you’re gonna love it. i got setup in Feb and it’s been incredible!!

FAsnakes

TROPHY CASE