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Powerwall 2 Available Energy After 2 Years

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No, but there are discharge testers that can do that for 48 volt packs. The biggest issue is finding one that can test, drain and log a 400 volt battery as it discharges. An additional challenge is acessing that 400 volts without voiding the warranty.


Kind of tangental question; but has Tesla had a good track record of honoring the 8 year warranty on the car batteries?

Like how does a Tesla owner actually check/track whether a 6 year old Model S is still charging up to 70% of the original kWh charge? And if an owner believes their battery is down to like 60% in the warranty period, has Tesla been pretty good about refurbing the battery pack?

My point of asking is; if Tesla has a consistent company behavior of honoring battery warranty, then I guess they would be pretty reliable for PW warranty.
 
TBH I have a somewhat similar situation myself, which is why I mentioned to you to call via phone. I have about 25% degradation, according to Tesla Energy Tier 1 support, and my powerwalls are about 1.5 years old. For about 24 hours it made me frustrated, then I thought to myself: There is no way that these things wont degrade another 5% in the next 8.5 years. So, I am not sure how you feel about it, OP, but what this means to me is that at some point they will drop below the value for warranty replacement, and they will have to be replaced.

OP, I use self powered mode, no idea what mode you use. I have not changed anything about my usage pattern at all. My reserve is set to 20% right now, and I go from 100% to about 25% daily, and am using virtually no energy from the electrical grid, same as I did last year.

Said another way, I am continuing to "use my powerwalls" with the expectation that, at some point in the next couple of years, they will lose another few percentage points of capacity, and will need to be warranty replaced. I have no qualms at all about "using the battery" because I am simply using it in the manner it was designed.

I came to the realization that I would much rather have this much degradation in the powerwalls now, than have them be at 26% in year 9 or something, where they would likely (with my luck) drop below the warranty value right after the 10 year installation anniversary.
Question, is there a limit to how often they will replace them? At the rate mentioned they might need a warranty at least 3 times.
 
Kind of tangental question; but has Tesla had a good track record of honoring the 8 year warranty on the car batteries?

Like how does a Tesla owner actually check/track whether a 6 year old Model S is still charging up to 70% of the original kWh charge? And if an owner believes their battery is down to like 60% in the warranty period, has Tesla been pretty good about refurbing the battery pack?

My point of asking is; if Tesla has a consistent company behavior of honoring battery warranty, then I guess they would be pretty reliable for PW warranty.

The model S battery is for "failure" over 8 years, AFAIK, there is no 70% number or such assigned to it. @MorrisonHiker might know more about that though as I dont have an S.

The model 3 has only been out since 2017, and the model 3 warranty is 70% capacity, but also has a mileage time frame on it depending on which model you buy.

The powerwall warranties are 70% capacity over 10 years and unlimited cycles as long as charged from solar. If charged from the grid, there is a kW throughput number.
 
I havent been able to get that to work on 20.49 which is what I am on now, but figured it might be firmware version related.



Thats a good question actually. My expectation is simply "replacement with a refurbished, like new unit" (I dont expect a brand new one, but do expect one thats been refurbished like new). Assuming I am still visiting this website either in a moderator capacity or regular user capacity when I reach that point, I will post and let people know my experience with the process.

I suspect that will happen in the next 12 months or so, unless my units stop degrading all together, and batteries dont work that way, so I actually feel like I am in decent shape to exercise the warranty in the next 12-18 months.
I believe the newer firmware is required for the local call (does not work for me either.)

On the warranty, links can be found here: Powerwall Owner Documents | Tesla Support

For PW2, the remedy section states:

If your Powerwall fails to comply with the above Limited Warranty, Tesla will, in its sole discretion, either repair your Powerwall (using new or refurbished parts), replace your Powerwall with an equivalent product (new or refurbished), or refund you the market price of an equivalent product at the time of the warranty claim. If your Powerwall is repaired or replaced under this Limited Warranty, the remainder of the original warranty period will apply to the repaired or replacement product. Under no circumstances will the original warranty period be extended as a result of your Powerwall being repaired or replaced.

So yes, they can use refurbished parts. I guess the most interesting question would be what "refurbished" means as to the battery capacity. That is, if you make a claim after 8 years, will you get a battery at 100%, or might you get something closer to 80% (but which Tesla still expects to make it to 10 years.)
 
Question, is there a limit to how often they will replace them? At the rate mentioned they might need a warranty at least 3 times.

Not that I know of, I am not an expert reading warranties. I dont know if one replacement is considered at fulfilling the warranty and the replacement product has a different warranty (somewhat common) or you still have the balance of your first warranty (more rare).

I suspect I will find out the answers to these questions at some point, as will OP.

EDIT:.. looks like @wjgjr quoted the applicable section from the warranty.
 
Looks like calling the service API works as well.

Capacity listed under the battery data for the products call:

curl --request GET --header 'Authorization: Bearer <API access token snipped>' 'https://owner-api.teslamotors.com/api/1/products'

{
"resource_type" : "battery",
"percentage_charged" : 72.1664802330442,
"site_name" : "Home Energy Gateway",
"id" : "STE20201019-00475",
"battery_power" : 990,
"sync_grid_alert_enabled" : true,
"energy_left" : 29167.5263157895,
"total_pack_energy" : 40417,
"components" : {
"grid" : true,
"market_type" : "residential",
"battery" : true,
"battery_type" : "ac_powerwall",
"solar" : true,
"solar_type" : "pv_panel",
"load_meter" : true
},
"battery_type" : "ac_powerwall",
"backup_capable" : true,
"asset_site_id" : "3f443fe6-8750-4d86-91e0-d41d37bc43bf",
"energy_site_id" : 160124898704,
"breaker_alert_enabled" : false,
"gateway_id" : "1232100-00-E--TG120266002KBS"
}


And then.....

curl --request GET --header 'Authorization: Bearer <API access token snipped>' 'https://owner-api.teslamotors.com/api/1/powerwalls/STE20201019-00475/status'

{
"response" : {
"site_name" : "Home Energy Gateway",
"percentage_charged" : 92.8953291149621,
"total_pack_energy" : 40433,
"id" : "1232100-00-E--TG120266002KBS",
"energy_left" : 37560.3684210526,
"battery_power" : 1540
}
}

Odd thing is that that total_pack_energy is very close between the calls but the direct battery status result is slightly higher 40433 vs 40417. Repeated calls show the same thing between both API calls.

Anyways, I'll add this to my dashboard to start tracking it over time. Looks like my capacity is still mostly new. Should be interesting to see what happens over the summer when it gets over 100F for several months.

Hmmm The energy left in the "products" call is completely wrong so I'm thinking the data is very stale from that call and more up to date from the battery status call.
 
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I believe the newer firmware is required for the local call (does not work for me either.)

On the warranty, links can be found here: Powerwall Owner Documents | Tesla Support

For PW2, the remedy section states:



So yes, they can use refurbished parts. I guess the most interesting question would be what "refurbished" means as to the battery capacity. That is, if you make a claim after 8 years, will you get a battery at 100%, or might you get something closer to 80% (but which Tesla still expects to make it to 10 years.)
oK, that makes sense. Thanks for posting
 
At your current rate you'll dip below 70% in a few months. The interesting thing will be how many times they need to replace your powerwalls over 10 years.

Once summer heat hits, I'll be cycling through 100% of my powerwall capacity (reserve set to 0%) running my AC in 110F weather. The powerwalls are outside. They are going to get absolutely fried.

On the day of the install, I asked the installer about putting them in the garage but he said it would take a lot longer and it made no difference to the life of the batteries. He totally lied because he wanted his job to be quicker and easier. I notified Tesla later after I did more research and realized that my summer temps are way outside the maximum 84 F optimal operating range. I offered to let them relocate my powewalls inside my garage where the temperature maxes out at about 85F when it's 110F outside. They replied that they could do it for $3300. I replied back that I wasn't spending money to extend the life of their product that is already warrantied for 10 years. When my 3 PWs dip below 70% in 2 years or less, I'll let them decide if they want to keep replacing them or move them to a more hospitable environment.


Has nobody yet discovered the API to pull capacity from the powerwalls?
max is 84 degrees? Since most place have temps over this, how do they even have a product?
 
Not that I know of, I am not an expert reading warranties. I dont know if one replacement is considered at fulfilling the warranty and the replacement product has a different warranty (somewhat common) or you still have the balance of your first warranty (more rare).

I suspect I will find out the answers to these questions at some point, as will OP.

EDIT:.. looks like @wjgjr quoted the applicable section from the warranty.
I know on my solar edge inverter, I paid to extend it 25 years, no matter how many replacements I get, the total does not go past 25 years is what they told me
 
TBH I have a somewhat similar situation myself, which is why I mentioned to you to call via phone. I have about 25% degradation, according to Tesla Energy Tier 1 support, and my powerwalls are about 1.5 years old. For about 24 hours it made me frustrated, then I thought to myself: There is no way that these things wont degrade another 5% in the next 8.5 years. So, I am not sure how you feel about it, OP, but what this means to me is that at some point they will drop below the value for warranty replacement, and they will have to be replaced.

OP, I use self powered mode, no idea what mode you use. I have not changed anything about my usage pattern at all. My reserve is set to 20% right now, and I go from 100% to about 25% daily, and am using virtually no energy from the electrical grid, same as I did last year.

Said another way, I am continuing to "use my powerwalls" with the expectation that, at some point in the next couple of years, they will lose another few percentage points of capacity, and will need to be warranty replaced. I have no qualms at all about "using the battery" because I am simply using it in the manner it was designed.

I came to the realization that I would much rather have this much degradation in the powerwalls now, than have them be at 26% in year 9 or something, where they would likely (with my luck) drop below the warranty value right after the 10 year installation anniversary.
I appreciate what you're going through. I also share your expectations that the PW's will degrade below 70% in due time. Since I'm in Florida, my reserve changes depending on cloud cover, thunderstorms, hurricane season, etc., but nothing that should cause them to degrade this fast. I have used balanced mode a lot to make sure I have the reserve I need during the night, and still have some reserve in the morning before sunrise.

My Model 3 is 15 months old and I'm not seeing this level of degradation. It seems more in line with other articles I've read.

Time will tell.
 
Not sure if this is affecting you, but it's an easy thing to check.

One thing I have noticed in my install is that the canbus wiring was a bit shoddy from my installers and caused a powerwall to not register correctly.

They're mounted in the corner of my garage with the status lights facing the corner so it wasn't immediately apparent that one was "offline".

I was starting to get skeptical that the peak hour power consumption was drawing down the batteries so quickly.

On a whim one night I noticed that one was glowing green and the other powerwall wasn't, so I opened the electrical compartment and when I pulled on the canbus wiring one of the wires came out.

I adjusted the connector to make sure everything was seated properly and my second powerwall re-registered.

That fixed my discharge issue.
 
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Not sure if this is affecting you, but it's an easy thing to check.

One thing I have noticed in my install is that the canbus wiring was a bit shoddy from my installers and caused a powerwall to not register correctly.

They're mounted in the corner of my garage with the status lights facing the corner so it wasn't immediately apparent that one was "offline".

I was starting to get skeptical that the peak hour power consumption was drawing down the batteries so quickly.

On a whim one night I noticed that one was glowing green and the other powerwall wasn't, so I opened the electrical compartment and when I pulled on the canbus wiring one of the wires came out.

I adjusted the connector to make sure everything was seated properly and my second powerwall re-registered.

That fixed my discharge issue.
Thanks for the tip. Both batteries appear to be operating normally, just their capacity to store energy is reduced. Lights are pulsing as usual as they charge and discharge. Good thought and something to keep an eye on.
 
I have about 25% degradation, according to Tesla Energy Tier 1 support, and my powerwalls are about 1.5 years old.

I need to correct the number in this post just a bit. When I was typing this out, I was going from memory on the discussion I had with Tesla energy support. I pulled the information from the powerwalls yesterday using the information from @gpez linked in this thread:


Once I had the capacity number that my powerwalls report, I calculated the percentage and its currently 21% degradation, not 25%. Small difference but in the interest of being accurate (and not exaggerating), figured I would self correct the number here.
 
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