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Powerwall 2 Available Energy After 2 Years

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,518
2,570
Northern California
Thanks for the tip. This was the last bit of data I was still getting from the cloud API. Now I can get all my stats locally from the TEG API and save the extra auth.
I think this only for the current information for the TEG, so you have to keep polling it. Don't know how often it is refreshed.

BTW if using the web browser you can log on in one window to authenticate and then you can use the API request in the same browser session.
 
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Redhill_qik

Member
Aug 16, 2020
315
224
South SF Bay, California
Do you think my calc using SOC and how much power was consumed is close?
The PW percentage that is displayed in the app is not the actual percentages. Instead it is an adjusted number that gives some headroom If you log into TEG the percentage that is there is accurate. The kWh numbers are rounded, so that will introduce additional errors. You can get the export/import numbers down to 0.01kWh through the REST API web interface.
 
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zƬesla

Member
Apr 16, 2020
409
142
US-NH
I think this only for the current information for the TEG, so you have to keep polling it. Don't know how often it is refreshed.

BTW if using the web browser you can log on in one window to authenticate and then you can use the API request in the same browser session.
I have a script on my server that polls powerwall data hourly and logs to a database. There is also a separate Grafana dashboard that pulls data more frequently.

Given the data collection is on a server, I set it up to auth directly without going through a browser.
 

getakey

Active Member
Jan 28, 2020
1,413
451
95762
The PW percentage that is displayed in the app is not the actual percentages. Instead it is an adjusted number that gives some headroom If you log into TEG the percentage that is there is accurate. The kWh numbers are rounded, so that will introduce additional errors. You can get the export/import numbers down to 0.01kWh through the REST API web interface.
Me question is how far off is the app. If I use the amount in the app and calculate 72% of original capacity, how far off do you think that is? I've only had these 18 months.
 

aesculus

Still Trying to Figure This All Out
May 31, 2015
4,518
2,570
Northern California
The field(s) that you want to look for is nominal_full_pack_energy and there will be one for each battery_block. The reported value is in watts, so for my two I am getting 27470 combined and individually 13782 and 13688 (6.5 months in service).
After 18 months running in Cost Savings mode my two PW (2) are showing 13680 and 13624 = 27304.

Has anyone run this on a brand new set to see what they are originally?
 

power.saver

Grid Specialist
Supporting Member
Mar 4, 2018
607
641
Arcadia, CA
After 18 months running in Cost Savings mode my two PW (2) are showing 13680 and 13624 = 27304.

Has anyone run this on a brand new set to see what they are originally?
I've been in cost savings mode for over 3 years and it currently shows 27558. It was 27570 in August of 2020, the last time I checked.
 
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mjhwa

Member
May 20, 2021
21
20
CA
The PW percentage that is displayed in the app is not the actual percentages. Instead it is an adjusted number that gives some headroom If you log into TEG the percentage that is there is accurate. The kWh numbers are rounded, so that will introduce additional errors. You can get the export/import numbers down to 0.01kWh through the REST API web interface.
I was wondering why there's a ~2% difference between the PW percentage readings.
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
Having just gotten my firmware update, ~16 months after install, my PWs are reporting 14029 and 13984 for the nominal_full_pack_energy, so still actually above 100% of the supposed size. Other than some time pre-PTO, have been operating in backup-only mode.


I was wondering why there's a ~2% difference between the PW percentage readings.
It appears to scale such that 100% is the same on both, but either 10% on the API = 5% on the app or 5% on the API = 0% on the app (I think most assume the former, but I'm not sure if it has been fully determined.) Essentially, the app is hiding the extra reserve the PWs keep to be able to re-start the system after being "completely" drained. In general, the system shuts off power exports at 10% on the API/5% on the app.
 

MorrisonHiker

S 100D 2021.32.20
Mar 8, 2015
10,157
9,676
Colorado
If you have firmware 21.13.2 or higher then you can log into the gateway and then go to this REST API page.

Replace the IP address with your gateway IP addresses
This is such an easy new way to get this information. I quickly learned that one of our Powerwalls (#4) is at 10.8 kWh but the Powerwalls 1-3 are all around 13.7 kWh and they have been used to power the house nearly 22 hours a day since installation. Total for all four Powerwalls is nominal_full_pack_energy":51898

I haven't verified yet but I'm betting Powerwall #4 is the "refurbished" one that we got at the end of 2019.

What'd odd is that #4 Powerwall shows energy_charged = 1292740 whereas Powerwalls 1 & 2 (from 2018) are 6467110 and 6533120 and Powerwall 3 (from 2019) = 3285180.

It doesn't look like #4 is being charged properly. I'll be reaching out to Tesla to ask about that one.
 

wwhitney

Member
Nov 2, 2017
968
1,320
Berkeley, CA
Having just gotten my firmware update, ~16 months after install, my PWs are reporting 14029 and 13984 for the nominal_full_pack_energy, so still actually above 100% of the supposed size. Other than some time pre-PTO, have been operating in backup-only mode.
I would be inclined to think that the "nominal" energy would be a figure in relation to the 14,000 Wh "total energy" spec on the spec sheet, rather than the 13,500 Wh "usable" energy spec.

For reference, on a 3 year old (almost exactly) system, in a passively conditioned basement and seeing fairly light duty, the figures reported are13,579 and 13,716 for my 2 PWs.

Cheers, Wayne
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
I would be inclined to think that the "nominal" energy would be a figure in relation to the 14,000 Wh "total energy" spec on the spec sheet, rather than the 13,500 Wh "usable" energy spec.

For reference, on a 3 year old (almost exactly) system, in a passively conditioned basement and seeing fairly light duty, the figures reported are13,579 and 13,716 for my 2 PWs.

Cheers, Wayne
That is a good point. What becomes interesting then, is whether the warranty would kick in at 70% of that 14 kWh number (9.8 kWh) or at 70% of 13.5 kWh (9.45 kWh), or at some other number based on the reserved amount.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
10,407
11,750
Riverside Co. CA
I really got the short end of the tesla battery lottery on this one, lol. Shrug... my vehicle, on the other hand, has is on the other end of the battery lotto scale, showing remarkably little loss over its 2.5 years and 26k miles.
 

getakey

Active Member
Jan 28, 2020
1,413
451
95762
This is such an easy new way to get this information. I quickly learned that one of our Powerwalls (#4) is at 10.8 kWh but the Powerwalls 1-3 are all around 13.7 kWh and they have been used to power the house nearly 22 hours a day since installation. Total for all four Powerwalls is nominal_full_pack_energy":51898

I haven't verified yet but I'm betting Powerwall #4 is the "refurbished" one that we got at the end of 2019.

What'd odd is that #4 Powerwall shows energy_charged = 1292740 whereas Powerwalls 1 & 2 (from 2018) are 6467110 and 6533120 and Powerwall 3 (from 2019) = 3285180.

It doesn't look like #4 is being charged properly. I'll be reaching out to Tesla to ask about that one.

If you have firmware 21.13.2 or higher then you can log into the gateway and then go to this REST API page.

Replace the IP address with your gateway IP addresses
when I enter that REST API page (with my TEG IP) the page does not load
 

FLB46169

Member
Mar 12, 2021
18
35
Ocala, FL
Just logged into the TEG with the info provided above. After 26 months, my 2 Powerwalls have nominal full pack energy of 20,247. The first has 10,165 and the second 10,082. This is slightly lower than the 20,520 Tesla told me when I started this string.

Thanks to all for the easy way to check the API. I'll be using that frequently to see where I am with the warranty.
 

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