Last week, my Powerwall 2 turned seven.
To celebrate, I stumped up $10 for a 1-month subscription to the excellent, third-party, NetZero Powerwall monitoring app and ran some diagnostics.
The results: just 6.4% degradation after seven years, averaging 0.7 cycles per day. I reckon that’s excellent.
If you’ve got an ageing Powerwall and the NetZero app, I’d love to hear your degradation numbers – post them in the comments. Let’s build a library of long-term real-life experiences.
Not Even Halfway Through Warranty
I’m also part of Tesla’s VPP, which (although winding up) came with a nice sign-up bonus: a warranty extension from 10 years to 15. I’m not even halfway through the warranty period – yay!
Honestly, if a meteorite flattened my battery tomorrow and I had to buy another, I’d go Tesla again. Two reasons:
1. Proven quality over time
Most battery hardware on the market looks solid when it’s new. But the truth shows in the long term. In that sense, my Powerwall 2 is performing far better than I expected.
Granted, you can’t buy a Powerwall 2 anymore, and the Powerwall 3 uses a different chemistry, but Tesla has earned confidence in its manufacturing quality and warranty support.
2. The app
Once the white boxes are on the wall, you’ll likely never physically interact with them again. The app is where almost all the product experience lies. It’s the interface between you and your energy system, the thing you check weekly, daily, or obsessively throughout the day. It’s what you must configure when you change electricity tariffs, need to change backup settings, or ensure your EV is not gonna guzzle expensive peak grid electricity.
The Tesla Powerwall app is, bluntly, a nine-and-a-half out of ten. Intuitive to configure, so the battery control software can get on with minimising your bills, while the interface is clear, responsive, and beautiful. It makes sense of what’s happening in your home at a glance. It shows solar generation, household load, battery state, and – if you have a Tesla car – EV charging in one tidy view.
Compare that to many other brands. Yes, they’ll have all that data, and if you look hard enough, you’ll find plenty of configuration settings, but the app feels like a teenager made it in their bedroom between Fortnite sessions.
The Tesla Powerwall app provides a terrific user experience.
Does Your Solar Company Take Their App Seriously?
Two stupidly simple User Experience (UX) tests will tell you if your solar company takes their app seriously:
- Do you keep getting logged out? With cheaper brands, you are constantly being prompted to log in. With Tesla, I can’t remember the last time.
- Does it take you straight to what matters? Tesla opens with my home’s status. Badly designed solar apps make me pick a solar system (or ‘plant’) every time. Ridiculous when most people only have one energy system in their home. Even if you do own multiple solar systems – let the user choose a default one to display!
Tesla even lets me put a widget on my home screen and my watch.
Small Details Matter
These are small details, but they make the difference between an app you use daily and one you avoid. And if you avoid the app, you’re not getting all the benefits of having a smart energy system in the first place. It goes without saying that if they can’t get these two things right, there’s no hope that they’ll make configuring your system for max savings intuitive. So you won’t, and that will cost you $$$.
So, seven years in, I’m still firmly in the Tesla camp. The hardware has stood the test of time, and the app is still miles ahead. If you’ve got a non-Tesla system with an app you actually enjoy using, I want to hear about it in the comments – because for me, the app is the product.
Phase Shift is a weekly opinion column by SolarQuotes founder Finn Peacock. Subscribe to SolarQuotes’ free newsletter to get it emailed to your inbox each week along with our other home electrification coverage.
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Ours is 7.5 years old, and have similar numbers to you
Capacity: 12.68kWh
Degradation: 6.07%
Energy Charged: 26,847kWh
Energy Discharged: 23,385kWh
These figures came from Home Assistant, so i dont need to buy a subscription and can graph over time.
We are based in Melbourne
Huh, you’re praising pretty basic functionality. My NeoVolt app (and webapp) clearly shows my house load, solar, battery state, charge. discharge etc. If I had an EV it would show that too. And I never have to re-logon to it.
Nice selection of historical data and diagrams too, which can be exported for further analysis.
Meanwhile on the Amber groups, I’m seeing endless issues with Tesla and VPP integration.
An interesting post, Finn. Particularly your last comment.
“……because for me, the app is the product”.
I suggest that the most important part of that statement is the first bit. Because you are an energy needs, I think your needs and interests are different to the great majority of solar energy and battery purchasers.
I for one, a keen supporter of renewable energy, have an absolutely different point of view. As does almost everyone I know. I would probably look at the app a number of times after my next system is installed and then rarely after that to check the system is working properly. Some of my friends would probably never even use it. To most people the product they purchase would be the panels, inverter and battery or perhaps even more likely the electricity bills they don’t pay.
Perhaps the more important questions are “Do you use the app? Regularly? What does it do for you? Do you care?” Even those answers would be biased on this this site of enthusiasts.
https://protonsforbreakfast.wordpress.com/2025/01/10/powerwall-battery-degradation-winter4/
I have been monitoring my Powerwall 2 for 4 years now. And although I love the product – and I don’t believe there’s anything better out there – I am sceptical about these low degradation figures.
I measure battery capacity each winter by waiting for days in which the Powerwall fully discharges from 100% to 0% (self-indicated) with little or no solar re-charge. In the UK we have many such days but perhaps in Australia this never happens!?
I find degradation of 0.4 kW/year or about 3% per year.
I still love the product and suspect that all competing products from a similar era are worse. But that’s what I measure.
Best wishes
Michael de Podesta
P.S. Thanks for the blog
I find the Fronius app is well laid out and easy to use.
Shows me everything I need to know.
Yes indeed, the app is the product. Unfortunately I only have a “dumb” phone, so my decision will be based on whether it has a browser-based control panel that I can use from my laptop. Or is this concept going the way of the dinosaur?
Hi Finn,
Thank you and your team for your excellent blog and web resources.
I have the Huawei Fusion App which shows me similar data.
I find it easy to use.I dont have an EV or a home battery yet..
Its about 5 minutes behind.
Its great to see where, when and how much energy we are using, and where its coming from.
On another subject, I need to automate three or four largish ( 3 to 6KW) floor heating loads and one airconditioner plus a car charger and home battery when I purchase these. The hotwater is heated with a heat pump (850W) on a timer.
I’ve enquired about Catch Solar Control relay but it aparently can only control one load even though it has six channels.Not sure how the Monacle App would work using multiple Catch Control relays. Do you have any suggestions of how I can maximise self consumption and minimise grid energy consumption, with automation?
Regards Phil
My Bluetti AC300 is now 3 years old and their app has improved over that time. I do tend to spend a lot of time using it.
It gives me all I want on one screen. SOC, PV, Grid (imports) and any DC or AC load. (No EV here yet, but it would not have the ability to monitor that).
Tapping on the SOC gives SOC for each of the modules and the current state of the BMS of each.
It has a total lifetime PV generation and CO2 saved estimate and $ saved total on the main screen. It also has historical data.
They have a grid connect model now and I expect the app for that might have more features.