On Wednesday Dec 16th my 4 powerwalls went into Storm Watch mode and were filled up to 100%. Storm watch lasted into December 17th which ended around 1200 in the afternoon. I never lost power or drew anything from the PWs. As of right now December 19th my powerwalls are showing 90% reserve. I'm actually surprised they have dropped 10% in 2 days. Is this normal? What is an expected loss?
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What is a normal dissipation of PW reserve?
- Thread starter coney27
- Start date
Not really. We had that snow storm in the North East this week and I quickly changed the reserve to 100% just to force the PWs to hold their entire charge. I normally keep them at 70% but with the pending storm I bumped it up to 100%.
We also had no outages which was shocking to me. So nothing was pulled from the PWs.
We also had no outages which was shocking to me. So nothing was pulled from the PWs.
I'm seeing almost the exact same behavior. Our 3 PW's are in the garage which is currently 55 degrees. We went into storm watch on the 16th as well and the walls were charged to 100% and stayed at 100% until the morning of the 18th. (I keep them on at 100% backup anyways). By yesterday morning they were down to 97% and stayed there all day. I checked this morning and they are at 91% losing 6% since I checked around 10pm last night (over roughly 11hrs). Our roof is still covered in snow so no solar production since Wednesday. No power outages and the app shows no discharge from the walls. A lot more drain than I expected.
I'm in the same exact boat. I just changed to back up only at 100% and ill keep an eye on it and see if it makes a difference. My PWs are now at 89% down 2% from 24 hrs ago.
I wonder what happens for PW's outside in freezing temperatures. I guess nothing is perfect. This is why I hope to implement all the possible processes for my energy needs. Standard grid normally. PW batteries if grid goes down. Generator if grid goes down and PW's dead. Makes wife happy.
I'm sure they drop even quicker. I've almost never had snow on the roof this long, quite depressing to get this whole bang out system installed and PTO on Wednesday only to generate 4KWH of energy since lol. The one thing I have learned over the years is no matter what you plan mother nature finds a way around it...
Yep, which is why I am hoping with my new mini split heat pumps, solar, maybe PW batteries, and a 22K generator, I end up have a zero energy bill and now power outage impacts to the house.
Shall see. Now, the wallet is sure getting a lot lighter Never temp mother nature lol. I often had water come into my basement from the same spot for years. I re-graded the property, dealt with water management outside and put a french drain on that wall. As the idiot that I am I said to my wife- well that's fixed. 6 months later for the first time ever I started getting water come in on a different wall of the basement. Doh! My neighbor had a 20kw gen installed in his house when hurricane Sandy came in and we lost power for 11 days. Within an hour of losing power his gen went down (capacitor if memory serves). No one to service and no parts available he finally got it up and running around day 9 of power being out. Mother nature finds a way...Yep, which is why I am hoping with my new mini split heat pumps, solar, maybe PW batteries, and a 22K generator, I end up have a zero energy bill and now power outage impacts to the house.
Ouch, but so true. But at least he tried. I am just amazed year after year I see on TV people lining up to buy things like snow shovels, generators, etc. and ask, why does it seem so many people are not prepared for things that seem to happen a lot? At least out west, the earth quakes to not happen often. But not that PGE is cutting power, I am prepared the best I can be.
Like most things powerwalls, I would imagine "it depends" (on things like whether the internal heating for the powerwalls needs to run, etc".
I doubt there is a solid concrete answer. I know people say "its in my basement, its not cold" but the product decides if its "too cold" and will turn on internal heating etc. I am not sure what those temps are.
I havent had a day when I get zero solar the next day so I dont know.
As others said, it depends a lot on circumstances. I posted the details elsewhere a bit back, but I've seen a loss of about 550 W per day for two PWs (so 275 W each) over a period of a month with the PWs in backup-only mode. I based this on the data from the API which shows the amount of energy imported and the amount exported (which is 0 with backup-only and no outages.) This is almost exactly 2% per day. With the PWs in the basement, I believe that there should be little or no heating/cooling.
aesculus
Still Trying to Figure This All Out
Do the PWs have battery heaters like the MS/MX do? If so perhaps they are triggered by location (weather) vs actual temp. This could account for larger daily losses during cold winter months.
I went through the same thing before. Was getting water intrusion into a building that was above grade and no standing water to account for it. Then I remembered that there was a large (2") power conduit coming down a hill into the building. I located a splice in a ground based distribution box uphill and noted that the conduit was not sealed. So after the ground saturated up top at the junction box, it was just filling up the conduit and draining into the building. Some waterproof foam fixed that.
I went through the same thing before. Was getting water intrusion into a building that was above grade and no standing water to account for it. Then I remembered that there was a large (2") power conduit coming down a hill into the building. I located a splice in a ground based distribution box uphill and noted that the conduit was not sealed. So after the ground saturated up top at the junction box, it was just filling up the conduit and draining into the building. Some waterproof foam fixed that.
Wow- scary when electrical is involved. When I was a kid we had a house fire that gutted the interior. After a year we finally get back in the house. Not a week or two later the lights were flickering- we couldn't figure out what was wrong. Called the contractor and he came out that night and it turned out that the service panel was really wet. The main pipe coming in was never sealed the rain was just pouring in it. They never installed a drip cap it was wide open.I went through the same thing before. Was getting water intrusion into a building that was above grade and no standing water to account for it. Then I remembered that there was a large (2") power conduit coming down a hill into the building. I located a splice in a ground based distribution box uphill and noted that the conduit was not sealed. So after the ground saturated up top at the junction box, it was just filling up the conduit and draining into the building. Some waterproof foam fixed that.
Yes. PW have thermal management.Do the PWs have battery heaters like the MS/MX do? If so perhaps they are triggered by location (weather) vs actual temp. This could account for larger daily losses during cold winter months.
I went through the same thing before. Was getting water intrusion into a building that was above grade and no standing water to account for it. Then I remembered that there was a large (2") power conduit coming down a hill into the building. I located a splice in a ground based distribution box uphill and noted that the conduit was not sealed. So after the ground saturated up top at the junction box, it was just filling up the conduit and draining into the building. Some waterproof foam fixed that.
the % loss might be what is described below:
“During winter months, a small amount of your Powerwall capacity is reserved to improve performance in cold weather. This may change your visible total capacity in the Tesla app. Rest assured, your total capacity has not changed – this small reserve is just set aside to improve performance.”
Preconditioning
When temperatures are low, all batteries have a reduced ability to charge. To help Powerwall counteract this, Powerwall uses Preconditioning. When temperatures are below freezing, Preconditioning turns on and heats your Powerwall to improve operation and charging performance.
To heat itself, Powerwall draws a small amount of energy, which then allows high-power charging. During a cold night, your Powerwall automatically preheats before sunrise so that maximum solar energy can be captured during the day.
You cannot customize this mode because Powerwall can best detect its internal temperature and knows when to enable Preconditioning.
During Preconditioning, the Power Flow screen may show energy flowing to your Powerwall from solar or the grid. This is normal behavior, and the energy is only being used to heat, not to charge.
During winter months, a small amount of your Powerwall capacity is reserved to improve performance in cold weather. This may change your visible total capacity in the Tesla app. Rest assured, your total capacity has not changed – this small reserve is just set aside to improve performance.
Preconditioning, in combination with Tesla’s unique liquid thermal management system, allows your Powerwall to operate at lower temperatures than any other home battery
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