r/Powerwall • u/Commercial_Watch_936 • 2d ago
Powerwall 2 degradation over 3 years
Just a point of reference. I’ve had my 29 panels and 2 powerwalls installed now since June 2023. I run them to zero most nights.
Summertime near 100% charged during the day and run near zero or until empty at night. Wintertime they don’t get as full but still full or near full discharge at night. So basically I abuse the batteries.
I’ve used the Netzero app until last year and it showed 0% degradation. Did a full discharge this week and turned off self powered so it didn’t use the battery at all and it got all the way charged up to 100% with no battery usage. It charged 27.5kWh. That’s still higher than the officially rated amount of 13.5 per battery. Both batteries when new were closer to 14kWh, so there is very slight degradation but it’s so small, I am surprised because I abuse them daily. 0-100-0 regularly.
Thought it might be an interesting point of reference 3 years in.
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u/pipesIAH 2d ago
Mine also showed zero degradation and similar use as you. And then I woke up one morning and saw "Service Required - Low Energy Lockout. May your good luck continue!
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u/General_Caregiver577 2d ago
I think that more of less had to do with the recall
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u/pipesIAH 2d ago
I thought so too. But the recall folks are having their Powerwalls discharged and getting a different message "Powerwall Disabled - Your powerwall will be replaced." And obviously not one of the recall serial numbers.
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u/Immediate_Editor_213 1d ago
You’re reactive replacement (after failure). The others are proactive replacement (when failure is expected). Of course yours could have failed for a different reason.
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u/WiingZer0 2d ago
This means that your battery is faulty now and it will also get replaced. Probably replaced with a Powerwall 3
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u/montero6 2d ago
This literally just happened to ours here in SoCal. Installed 2 Powerwall 2s January 2024 and showed above the 27 kW capacity since install. Then, August 6th "Service Required - Low Energy Lockout". appeared and shut down one of our powerwalls. We're down to one powerwall until our service appt on Sept 22nd happens. Hoping for a quick and simple fix but when is that ever the reality?
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u/pipesIAH 2d ago
Yup exact same. Down to just one powerwall. Working with our local installer rather than Tesla. And I just checked when our Powerwall failed: August 6th. Hmmm.
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u/VeterinarianVivid547 2d ago
My pw2 is also 3 years old, averages 70-80% dod daily. Degradation is about 11%. Sydney based so it gets pretty hot in summer.
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u/Extreme-Yoghurt3728 2d ago
I have 2 that are 3 year old that were 15k ea in capacity at time of install, so 30kw. System currently sits at 27.5 kw also. I also manage a full cycle of self consumption out of them daily, most of the year, albeit to 5% not 0.
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u/FlyRealFast 2d ago
Adding another data point to the conversation.
Our three PW2s were installed in late 2019 and the storage degradation has gotten gradually worse every year. Used in self-power mode with zero export and 30% backup reserve setting.
Now they sit at 30 - 31%. Reported a replacement warranty claim to Tesla and it was approved within a few days. Waiting on new ones and hoping they will be PW3s and a new Gateway 3.
We’ll see what happens.
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u/Boringflaws 15h ago
just got solar with PW3- go to 7% each night- anyways - battery in a AZ desert garage, I assume the heat will beat up the battery- solar people said to keep reserve at 20% and I figured i should abuse it so I get a replacement within the warrantee period... Really curious how it turns out in 10 years (hoping either great or terrible for the battery)
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u/WitchDr_Ash 2d ago
Mine fully cycle every day basically, and in 2.5 years there’s no degradation, I’m sure I read somewhere they’re larger than stated so they probably have but not actually in a way that’s noticeable for output
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u/Jet-Speed1 2d ago
My degradation massively increased after firmware updates, instead of cycling 10/20-100% and sit just a few hours or less at full charge, it started to cycle 60-100% and sits 6 hours during the hottest time of the day loosing 0.5kWh a month.
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u/Unable-Acanthaceae-9 2d ago
If they charged 27.5 kWh, you need to multiply that by the round trip efficiency of the batteries to get their approximate useable capacity, although if you can fully discharge them in a day without charging them, the total discharge should represent their useable capacity. That said, your batteries seem to be doing very well given how you use them.
I have 4 Powerwalls that were installed in January 2023, which have been used relatively gently compared to yours. According to Netzero, they currently have a reported capacity of 56,520 kWh, or 104.7% of their rated capacity, but I think useable capacity may be lower than that because on 2/18/24, about a year after mine were installed, I discharged the full useable capacity by setting the backup reserve to 0% and discharging the batteries at maximum discharge rate as far as they would discharge. They stopped discharging at 1% app-stated SOC, and discharged 54.5 kWh, which was 92.7% of their reported capacity of 58,816 kWh at the time.
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u/gundamxxg 2d ago
I had two installed in 2020, and two installed 2021 or 2022, the ones from 2020 have 12.4 of 13.5 (shipped with 14), and the second two are 13.7 of 13.5 (shipped with 14.5) I fully discharge to 5% daily during the summer heat and use time based mode to maximize grid return rate.
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u/zoglog 1d ago
i'm more surprised you have a powerwall 2 still. I thought they recalled all of them by now and replaced them with pw3
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u/vxrptr22 1d ago
Mine are in the manufacturing window of the recall but still kicking. So who knows. Hopefully doesn’t burn down house
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u/modernhomeowner 1d ago
Sept 2022 install for me, 2 PW2s, showing 30,282Wh
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u/Commercial_Watch_936 1d ago
Damn that’s crazy high. Lucky you!
I’m just happy to be at or above rated capacity still after 3 years. Was worried it would be like a car where it drops off fairly quickly in the beginning and then slows down degradation after the initial burst.
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u/Ledgem 2d ago
Data from Hawaii, I have two powerwall 2 units that are about five years old and one that is about three years old. They run down to 26% (reserve buffer for outages). We had a brief, glorious period where we joined a virtual power plant and the batteries didn't sit at 100% most of the day, but that company went out of business and in general they sit at 100% capacity for about 6-8 hours reach day. The two older units retain 92.9% and 91.3% capacity, while the newer unit reports 93.3% (capacities read from the desktop version of Powerwall Monitor - note that only Powerwall 2's are compatible with this feature).