Powerwall 2 Available Energy After 2 Years

[Redhill_qik]

Mine are reporting 13756 and 13800 so clearly they can go above 13500.

Right, but you were saying that this would be scaled from 14,000 to 13,500 which would mean that your 13,800 would actual be 14,311 (13,800 * 14,000/13,500).

I can understand that they build the PWs with 14 kWh of batteries and advertise 13.5 kWh, but not that these numbers will be further scaled.

 

[power.saver]

Right, but you were saying that this would be scaled from 14,000 to 13,500 which would mean that your 13,800 would actual be 14,311 (13,800 * 14,000/13,500).

That was @wwhitney who said they might be scaled.

I can understand that they build the PWs with 14 kWh of batteries and advertise 13.5 kWh, but not that these numbers will be further scaled.

I agree. I believe these numbers report the true pack capacity.

 

[wwhitney]

I'm not saying that the reported numbers are being scaled; that presupposes some starting scale. I'm just saying that since it is called "nominal", I would expect a new PW to report "nominal_full_pack_energy" to be 14,000 not 13,500. And I would expect that a fully depleted Powerwall would report around 500 for "nominal_energy_remaining" (or maybe it's a bit more). [Someone should get the data.] That would be the 13.5 kWh usable advertised on the spec sheet.

In which case, the actionable level for the 70% warranty would be a "nominal_full_pack_energy" of 500 + 70% * 13,500 = 9,950.

Cheers, Wayne

 

[gpez]

My PW2 was installed 4/2019 so it's about 27 months old. It's only use for backup (I've barely cycled any power through it) and is outside on a north garage wall in a fairly temperate climate (does not get much below freezing or hotter than the 90s normally).

"nominal_full_pack_energy":11901

That's quite a bit lower than I'd like to see

Edit:

My energy charged vs discharged is awesome though!

"energy_charged":287520,"energy_discharged":24200

 

[gpez]

I'm not saying that the reported numbers are being scaled; that presupposes some starting scale. I'm just saying that since it is called "nominal", I would expect a new PW to report "nominal_full_pack_energy" to be 14,000 not 13,500. And I would expect that a fully depleted Powerwall would report around 500 for "nominal_energy_remaining" (or maybe it's a bit more). [Someone should get the data.] That would be the 13.5 kWh usable advertised on the spec sheet.

In which case, the actionable level for the 70% warranty would be a "nominal_full_pack_energy" of 500 + 70% * 13,500 = 9,950.

Cheers, Wayne

I think this is assuming the Powerwall math on reserve is set at 500wh rather than a % of total capacity. Ie 70% warranty means 500wh * .7 = 350wh reserve.

That said, I believe your assumption is likely correct. It's just an assumption to call out.

 

[kairojya]

This is an interesting thread, I’m glad I found it. I’ve been curious about degradation and usage patterns, as the I’ve read a lot of discussions about the topic with the cars. I’ve had a Model 3 for 8 months and have become accustomed to rarely charging it over 70% for example.

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?

My system was installed on 6/24/2021. I’ve passed inspection but I’m pre-PTO. I have been using the system for 14 days while minimizing my grid export as much as possible. I’ve been discharging my 2 Powerwalls by 60%~ overnight. The Powerwalls are installed in my enclosed unconditioned garage in Florida where it has hit 85-95F peaks since my install.

"nominal_full_pack_energy" : 27389
"nominal_energy_remaining" : 22128

Powerwall+ (3012170-25-B)
"nominal_full_pack_energy" : 13733
"nominal_energy_remaining" : 11142
"energy_charged" : 105720
"energy_discharged" : 85180

Powerwall2 (3012170-05-B)
"nominal_full_pack_energy" : 13656
"nominal_energy_remaining" : 10986
"energy_charged" : 112210
"energy_discharged" : 91180

I forgot to check the state of energy when I pulled this earlier. I was somewhere between 70-80% as reported by the web UI.

 

[aesculus]

My system was installed on 6/24/2021. I’ve passed inspection but I’m pre-PTO. I have been using the system for 14 days while minimizing my grid export as much as possible. I’ve been discharging my 2 Powerwalls by 60%~ overnight. The Powerwalls are installed in my enclosed unconditioned garage in Florida where it has hit 85-95F peaks since my install.

"nominal_full_pack_energy" : 27389

Woo who. My 27304 for 18 months is not bad. Less than a light bulbs worth of decay.

 

[wwhitney]

Less than a light bulbs worth of decay.

Most light bulbs are going to use more than 85 Wh of energy over their lifespan.

Cheers, Wayne

 

[bmah]

I finally decided to read through this whole thread and figure out how my system is faring. 3 PW2 units installed in March 2019.

dock2:~% cat sys.json | jq . | grep nominal_full_pack_energy "nominal_full_pack_energy": 31922, "nominal_full_pack_energy": 10746, "nominal_full_pack_energy": 10612, "nominal_full_pack_energy": 10564,

(In case it's not clear, the first number is the entire system, the remaining three are for each battery individually.)

If I did the math right, it's about about 22% loss over ~2.5 years, compared the figures posted by @kairojya a few posts above. Calculations based on some measurements over the last 12 hours give a slightly better picture...33.3 kWh system capacity for a loss of about 18% (assuming a baseline of 13.5 kWh x 3 = 40.5 kWh).

I should probably add some fields from the system_status output to my logging.

Bruce.

 

[jjrandorin]

I finally decided to read through this whole thread and figure out how my system is faring. 3 PW2 units installed in March 2019.

dock2:~% cat sys.json | jq . | grep nominal_full_pack_energy "nominal_full_pack_energy": 31922, "nominal_full_pack_energy": 10746, "nominal_full_pack_energy": 10612, "nominal_full_pack_energy": 10564,

(In case it's not clear, the first number is the entire system, the remaining three are for each battery individually.)

If I did the math right, it's about about 22% loss over ~2.5 years, compared the figures posted by @kairojya a few posts above. Calculations based on some measurements over the last 12 hours give a slightly better picture...33.3 kWh system capacity for a loss of about 18% (assuming a baseline of 13.5 kWh x 3 = 40.5 kWh).

I should probably add some fields from the system_status output to my logging.

Bruce.

Glad to know its not just me and the OP that have energy in the 10's on our powerwalls (misery loves company, lol).

 

[bmah]

Glad to know its not just me and the OP that have energy in the 10's on our powerwalls (misery loves company, lol).

lol cry

I'm gonna start logging that to my Grafana dashboard so I can get an idea of trends...wish I had thought of that a couple years ago. My weekend project if I don't get to it before then.

Bruce.

 

[jboy210]

lol cry

I'm gonna start logging that to my Grafana dashboard so I can get an idea of trends...wish I had thought of that a couple years ago. My weekend project if I don't get to it before then.

Bruce.

You guys have me worried. I am going to add these to my logging app on my RPi.

 

[jjrandorin]

@bmah when were your powerwalls installed? I wonder if there was something about the ones around that time period or something? FWIW I escalated (again) a ticket to tesla energy support tier 2, because when I did last time the 1st level agent let it slip that "your powerwalls didnt have 13.5 when they were installed". Since this is still bugging me, I called them again and complained that when I purchased them, they were supposed to start with 13.5 and they didnt.

The tier 1 agent wanted to know, in so many words, "how did you determine this information" and I said "the agent last time told me".. this agent said "oh....". They then told me "I see notes from your previous call on this subject and that tier 2 came back and said you had not met the threshhold for warranty action of 70% yet", and I said "yes but I was supposed to start with 13.5 and I didnt".

Shrug, will see where it goes, I dont have high hopes of them doing anything until I get to the threshhold. Will update this thread any other way.

 

[FLB46169]

@bmah when were your powerwalls installed? I wonder if there was something about the ones around that time period or something? FWIW I escalated (again) a ticket to tesla energy support tier 2, because when I did last time the 1st level agent let it slip that "your powerwalls didnt have 13.5 when they were installed". Since this is still bugging me, I called them again and complained that when I purchased them, they were supposed to start with 13.5 and they didnt.

The tier 1 agent wanted to know, in so many words, "how did you determine this information" and I said "the agent last time told me".. this agent said "oh....". They then told me "I see notes from your previous call on this subject and that tier 2 came back and said you had not met the threshhold for warranty action of 70% yet", and I said "yes but I was supposed to start with 13.5 and I didnt".

Shrug, will see where it goes, I dont have high hopes of them doing anything until I get to the threshhold. Will update this thread any other way.

I recently worked with a neighbor who had his 2 PW system installed about 6 months before mine in April 2019. I showed him how to access the system status. Both of his PW's were showing capacity in the 13's. My 2 PW's are in the 10's as of today. I agree with you that there is no way my PW's had 13.5 at the start if someone with the same climate conditions is seeing no degradation. Unfortunately, I have no way to prove it.

 

[h2ofun]

I recently worked with a neighbor who had his 2 PW system installed about 6 months before mine in April 2019. I showed him how to access the system status. Both of his PW's were showing capacity in the 13's. My 2 PW's are in the 10's as of today. I agree with you that there is no way my PW's had 13.5 at the start if someone with the same climate conditions is seeing no degradation. Unfortunately, I have no way to prove it.

and how does one access system status again?

 

[bmah]

@bmah when were your powerwalls installed? I wonder if there was something about the ones around that time period or something? FWIW I escalated (again) a ticket to tesla energy support tier 2, because when I did last time the 1st level agent let it slip that "your powerwalls didnt have 13.5 when they were installed". Since this is still bugging me, I called them again and complained that when I purchased them, they were supposed to start with 13.5 and they didnt.

The tier 1 agent wanted to know, in so many words, "how did you determine this information" and I said "the agent last time told me".. this agent said "oh....". They then told me "I see notes from your previous call on this subject and that tier 2 came back and said you had not met the threshhold for warranty action of 70% yet", and I said "yes but I was supposed to start with 13.5 and I didnt".

Shrug, will see where it goes, I dont have high hopes of them doing anything until I get to the threshhold. Will update this thread any other way.

Installed in March 2019.

I wonder if there's any value in my logging a support call with Tesla Energy. I wish I'd been logging system_status all along.

Even if they decide someone qualifies for warranty action, given the current supply constraints I wonder how long it'd take to actually take to do some kind of remedy (which I presume would mean swapping out entire Powerwall units).

Bruce.

 

[jboy210]

Installed in March 2019.

I wonder if there's any value in my logging a support call with Tesla Energy. I wish I'd been logging system_status all along.

Even if they decide someone qualifies for warranty action, given the current supply constraints I wonder how long it'd take to actually take to do some kind of remedy (which I presume would mean swapping out entire Powerwall units).

Bruce.

I think it is best to get the ball rolling if you think you are due a replacement unit. That will ensure that even if it takes a while, at least you will be in the queue and have a request/reference number to refer to with the service people.

 

[jjrandorin]

and how does one access system status again?

There is information in this stickied thread:

Discussion: How to get status information from your Powerwalls

This is the best I can do that's as "easy" as possible, all done in a Chrome browser. Using your gmail account create a new blank Google Sheet. In your new blank Google Sheet open Tools > Script editor: When the Apps Script page loads in another tab, clear whatever is in there and paste in...

teslamotorsclub.com

 

[bemyax]

20 months since commissioning one PW - nominal full pack energy 11273

 

[aesculus]

and how does one access system status again?

Logon to your PW Gateway web address with your Tesla account credentials

Then just https://gw_ip_address/api/system_status

Easy peasy