Got two PWs last month, thank god for flashlights...

[Electricfan]

Sitting here with no power, 4am Sunday morning. Btw, if you call Powerwall tech support at this time, you get a warm recorded greeting asking you to hold until a representative can help you. I held for ten minutes. Then a nice guy answered the phone who asked me if I was in a safe location. I said I was, and he asked me how he could help. When I told him I was trying to reach powerwall support he told me their phone rolls over to roadside support. Why Tesla can't afford a separate system I don't know, but I spent 10 minutes on hold for nothing.

Got two powerwalls installed at the end of May. This morning when the power went out my phone had a text saying my powerwalls were supplying power to my home because the power was out. But the text was not correct, as no power outlets or lights work. First world problems. Still, I paid a lot for those things and they aren't helping at all right now.

Will update this post so others can learn. Maybe its user error somehow. I have them set for time-base control, cost savings mode. But the reserve is set to 10% and I thought that still worked in the event of an outage. Maybe not.

 

[boaterva]

Didn’t the installers (or you) test that the PWs actually worked when grid power was cut? Mine did. Seems like something to do before letting them leave. Sorry it didn’t work but seems like an installer issue. Any reserve should be enough to power whatever loads are backed up for some time.

 

[Chancellor32]

Sitting here with no power, 4am Sunday morning. Btw, if you call Powerwall tech support at this time, you get a warm recorded greeting asking you to hold until a representative can help you. I held for ten minutes. Then a nice guy answered the phone who asked me if I was in a safe location. I said I was, and he asked me how he could help. When I told him I was trying to reach powerwall support he told me their phone rolls over to roadside support. Why Tesla can't afford a separate system I don't know, but I spent 10 minutes on hold for nothing.

Got two powerwalls installed at the end of May. This morning when the power went out my phone had a text saying my powerwalls were supplying power to my home because the power was out. But the text was not correct, as no power outlets or lights work. First world problems. Still, I paid a lot for those things and they aren't helping at all right now.

Will update this post so others can learn. Maybe its user error somehow. I have them set for time-base control, cost savings mode. But the reserve is set to 10% and I thought that still worked in the event of an outage. Maybe not.

Are they out of power? What’s their % right now?

 

[Electricfan]

Are they out of power? What’s their % right now?

The house still has no power at 1PM central. It has come on for a few minutes about 4 times since going out. I plugged a battery backup in and connected my internet router, so now I can connect to the internet, and since my powerwall's backup gateway is connected by a cable to the router I can see the powerwall. It shows the powerwall at 0%. Although the sun is shining, the powerwall is not charging.

Yes, before the installer left he tested a grid outage and my AC worked, which seemed what he was most concerned about.

I have no idea why the batteries aren't charging. There are clouds, but the panels are producing at least 1.5 to 2.0 kw right now, and should have been producing since the sun came up. The power has been out in the house since 4am. So there's no way the house has used any power. So why aren't the batteries charged to at least 20 or 30% ?? Why do I have zero power?

Sure wish this had happened when powerwall tech support was open.

 

[Electricfan]

Update, I called tech support and they answered. I was thinking they weren't open until Monday but I was wrong.

We powered off my powerwalls.
Then we turned their breakers off and waited 5 min.
Then turned the breakers back on.
Then turned the powerwalls back on.

They started discharging 400 watts to the house. I also had previously killed all the large loads, water heater, AC etc.

He did not know exactly why, but the backup gateway or the powerwalls, I'm not sure which, went into stop mode after supplying the house for about 30 minutes when the power first went out.

When we were doing the four steps listed above, he had gotten me connected to the backup gateway on my phone's chrome browser, and when I first connected the powerwalls were at 5% power. And he said they were "stopped" (gateway or powerwalls, not sure what).

After doing the four steps above, the powerwalls came on and started powering the house, but solar was not coming in. He said it would take about 5 minutes, and that was accurate. Now I am charging the powerwalls at about 4kw, with the AC off.

Summary, I need to set my reserve to at least 20%. He said below 10% it stops powering the home. Its still a little bit of a mystery why the powerwalls "stopped". I also wonder if I had not callled him, what would have happened when the grid came back up. I'm assuming the powerwalls would have stayed off. So the four steps above will be my "go to" method of getting the system back running if this happens again But I wish if the powerwalls run out of juice and the grid is out, that they would have a more graceful automatic way to start charging again when the sun comes up and solar is available. I lost most of today's sun power.

5 stars for powerwall tech support. I'm not going to deduct for them not being there at 4am.

2 stars for my powerwalls. They supplied some power to the house, even though the reserve was too low for them to help much, but they didn't recover when the sun came up, and if I hadn't called tech support they'd have never worked again.

2 stars for Tesla information / powerwall owner education. They helped me get the powerwalls working the way I want, but nobody said anything about "below 10% the powerwalls will not support the home", or mentioned the four steps above to get the system back when it craps out.

Hope this helps somebody.

 

[dandrewk]

You shouldn't ever have to perform those steps. My impression is the tech support person was correct. The power went off, the walls supplied juice until nearly depleted and then switched off. I'm not sure why you had to cycle the batteries in order to get them charging via solar. Were you perhaps on the TOU schedule and the system was set to put excess generation into the grid?

 

[NuShrike]

I wonder if your car was charging when the blackout hit.

With Telsa'a current, lacking controls, car-charging would definitely drain the PWs.

 

[boaterva]

Glad they got you up and running!

The real point here is to set the PWs to have the right reserve for the house if the priority is to backup the house. Other people’s priority is to timeshift and make money by arbitrage but you can’t do both if the power fails while you’re at a low level.

Another issue as was mentioned if you have a random large load on the PWs (like the cars) it can eat up all the PW power when you shift over before you know it leaving you with nothing to ‘live on’ before the sun comes up or things get back to normal.

For example, we don’t have the cars on the PWs but could always run an extension cord to a dryer outlet if we are out for days and then have tons of sun power to charge cars (if needed).

Something to think about for anyone who has large loads that can drain PWs quickly overnight if the grid goes out.

 

[MorrisonHiker]

You might want to read PowerWall Cold Start without Grid Power

As others mentioned above, it sounds like the Powerwalls worked fine and were powering the house. They were drained down to 5% and then couldn't start things back up. I ran into a similar issue in March when my batteries got down to 5%. The Powerwalls kept putting out a high frequency which caused the inverters to repeatedly shut down. Tesla came out and did a firmware update on the inverters and there's been a Powerwall firmware update since then which should limit the frequency. We did a test back in March before the firmware update and things worked fine when the batteries were charged. We need to do another off-grid test to confirm the right frequency is sent when the grid is down and the battery state of charge is low. Others have recently reported calling Tesla and they reconfigure the Powerwalls/Gateway with the necessary inverter information so that the proper frequency is sent.

 

[Electricfan]

I asked the powerwall tech support person to send a summary so I could post it here. Below is what he sent me in an email.

"Your grid outage began on 07/07/19 at 2:19 AM your time. At 2:51 AM the Powerwalls stopped reporting when they were at a low state of charge and by late morning they were down to around 600 watts each.


This morning starting at 9:06 AM the Powerwalls tried to turn back on but something requiring a brief but large surge of current prevented it. After turning off all large drawing loads and power cycling the system, the Powerwalls were able to discharge power to the home and form a micro grid so that minutes later your PV system could start generating power for your home and to charge the Powerwalls.


As mentioned on the phone, since the last 10% of the Powerwall’s stored energy is reserved during grid outages to check for available solar power to charge from, we recommend increasing the reserve to at least 20% to have 10% available as usable power during an outage."

That last line is important - they use the last 10% to check for available solar. I now have my reserve set to 25%. I'll probably leave it there unless I see that I can't provide most of my own power during the day with it set that high. Then I'll probably choose a lower setting even though I'll be mostly out of luck if the grid is lost unexpectedly.

 

[Jigglypuff]

Sounds like you've been running off the power walls until they drain each night then switching to utility power. Then, when the power went out, you'd already drained them so they weren't available for backup power. You should post screenshots of powerwall usage yesterday and today. Then we can confirm. I'm thinking user error. Charging your EV on battery power, if you do, is generally a wasteful idea. Overnight power rates are typically cheap.

 

[MorrisonHiker]

Sounds like you've been running off the power walls until they drain each night then switching to utility power. Then, when the power went out, you'd already drained them so they weren't available for backup power. You should post screenshots of powerwall usage yesterday and today. Then we can confirm. I'm thinking user error. Charging your EV on battery power, if you do, is generally a wasteful idea. Overnight power rates are typically cheap.

In the past, we could used Advanced-TBC to schedule hours when the Powerwalls would definitely not discharge during the off-peak period. Tesla changed things in the 1.37.x firmware so that ours are now drained overnight, starting around 4:30 am. At first, I was a little annoyed but the way they changed it leads to me having a larger reserve which is then used shortly before the sun comes up. Previously, the Powerwalls would only charge up as high as was predicted would be needed to get use through the end of the part-peak period. This caused the Powerwalls to only charge to 80% or so and then immediately start discharging hours before peak ever started. Now, the Powerwalls are charged up to 100%, giving us an extra 20% when going into the off-peak period. The Powerwalls then start discharging around 4:30 and get down to our reserve percentage by around 7 am every morning. So the new firmware has advantages and some disadvantages. I'm sure they will continue to tweak things going forward to find the right balance. Elon did recently reply to our tweet indicating future firmware updates will enable better communication between vehicles and the Powerwalls/gateway to prevent the cars from draining the Powerwalls if there is an outage. Currently, they only send the notification but if you don't get the notification, then most people with whole-house backup wouldn't even know there was an outage.

 

[NuShrike]

On TBC-balanced, I've been seeing random pre-drain before the sun gets up. I've set my shoulder to start at 6am -- e.g. off-peak is 1am to 6am,.

I've seen TBC start discharging (in off-peak) starting randomly between 4am to 5am. Generally it's been okay as it seems to be predictive to empty the PWs enough to full-recharge by 12pm.

I doubt this is what drained your PWs as you've already had a full-drain schedule, but this is one of the nits of TBC.

 

[Electricfan]

Thinking about this, I believe there is another take-away besides the new knowledge that the PWs don't use power for your house below 10% where they start saving power to test for solar power so they can come back on normally. The new take away is this: if you have an outage and your PWs drain completely (down to 10% and then all the way down to virtually empty because they use the 10% checking solar) before the grid is restored and before the sun comes up, then your PWs will shut themselves down and you must:

a) go to your breaker panel and kill all the large loads like AC, hot water heater etc
b) do the four step procedure above to get the powerwalls back active.

I think if you don't do this dance you will be calling powerwall tech support because your PWs will never come back by themselves with no intervention or anything from you or Tesla remotely (I don't know what they can do remotely). I could be wrong though - maybe they'd come back on if grid power is restored. But I don't think so.

 

[Electricfan]

Sounds like you've been running off the power walls until they drain each night then switching to utility power. Then, when the power went out, you'd already drained them so they weren't available for backup power. You should post screenshots of powerwall usage yesterday and today. Then we can confirm. I'm thinking user error. Charging your EV on battery power, if you do, is generally a wasteful idea. Overnight power rates are typically cheap.

Yes, you are right it was user error in setting my reserve too low - 10%. I have it at 25% now. The PWs do get low at night after the sun goes down before 9pm and it switches to utility exactly as you said. I do charge my cars at night, but the PWs are not discharging at that time because of TBC. I agree putting solar into the PW battery only to take it out later and put it in a car battery is wasting the power lost in moving it into and out of the batteries. Too bad that process isn't more efficient.

 

[Electricfan]

In the past, we could used Advanced-TBC to schedule hours when the Powerwalls would definitely not discharge during the off-peak period. Tesla changed things in the 1.37.x firmware so that ours are now drained overnight, starting around 4:30 am. At first, I was a little annoyed but the way they changed it leads to me having a larger reserve which is then used shortly before the sun comes up. Previously, the Powerwalls would only charge up as high as was predicted would be needed to get use through the end of the part-peak period. This caused the Powerwalls to only charge to 80% or so and then immediately start discharging hours before peak ever started. Now, the Powerwalls are charged up to 100%, giving us an extra 20% when going into the off-peak period. The Powerwalls then start discharging around 4:30 and get down to our reserve percentage by around 7 am every morning. So the new firmware has advantages and some disadvantages. I'm sure they will continue to tweak things going forward to find the right balance. Elon did recently reply to our tweet indicating future firmware updates will enable better communication between vehicles and the Powerwalls/gateway to prevent the cars from draining the Powerwalls if there is an outage. Currently, they only send the notification but if you don't get the notification, then most people with whole-house backup wouldn't even know there was an outage.

Are you using TBC with cost savings? And do you just have peak and off-peak defined, or is there some way to enter a "shoulder" time that is between peak and non-peak? I have mine on TBC and cost savings, with a peak defined from 6am to 9pm. Mine has discharged the powerwall when it "shouldn't" by my estimation anyway, but only very little, so it doesn't bother me. I do not see a regular discharge at 4:30am like you seem to. Why you do is a mystery, unless 4:30am is a boundary in your TBC settings somewhere. Have you called Tesla Powerwall support about it? It would be awesome if they could make the cars respond and not charge during a grid outage when the PW was discharging, if you choose that setting. Some might want the car to charge anyway I'm sure.

 

[MorrisonHiker]

Are you using TBC with cost savings? And do you just have peak and off-peak defined, or is there some way to enter a "shoulder" time that is between peak and non-peak? I have mine on TBC and cost savings, with a peak defined from 6am to 9pm. Mine has discharged the powerwall when it "shouldn't" by my estimation anyway, but only very little, so it doesn't bother me. I do not see a regular discharge at 4:30am like you seem to. Why you do is a mystery, unless 4:30am is a boundary in your TBC settings somewhere. Have you called Tesla Powerwall support about it? It would be awesome if they could make the cars respond and not charge during a grid outage when the PW was discharging, if you choose that setting. Some might want the car to charge anyway I'm sure.

I have mine set to TBC-Balanced. The shoulder periods are the gray periods shown below. You can just drag the start/stop times of the peak/off-peak periods to increase or decrease the shoulder period duration.

 

[Electricfan]

I have mine set to TBC-Balanced. The shoulder periods are the gray periods shown below. You can just drag the start/stop times of the peak/off-peak periods to increase or decrease the shoulder period duration.

View attachment 427852

Interesting. So what do you want your powerwall to do in the "shoulder" area between peak and non-peak?

 

[MorrisonHiker]

Interesting. So what do you want your powerwall to do in the "shoulder" area between peak and non-peak?

They power the house! Our rates are roughly 8 cents/kWh off-peak, 12 cents/kWh shoulder/part-peak and 18 cents/kWh peak. The Powerwalls have more than enough capacity to power the house through peak, part-peak and even part of the off-peak period. We really never use anything besides off-peak grid power.

We would prefer a "timed self-powered" mode so that I could power my house all but a few hours a night. Since such a mode doesn't exist, we use the TBC-Balanced. Solar and the Powerwalls power the house for about 20 hours a day. We charge two cars at off-peak rates. The third car usually charges at off-peak rates too but since receiving firmware 1.37.1, the Powerwalls kick in for part of the charging until solar takes over (or charging is complete).

 

[Electricfan]

Well this morning my powerwalls started discharging at 4am, just because I said in a post they didn't do this. Seriously, I think maybe it happened because there was a lot of sun yesterday here and they were at a higher charge level than normal this morning. Maybe they were trying to make room so they wouldn't hit 100%?? I think 100% is bad for batteries in general, so if they charged to 100% regularly it wouldn't be good for them - cycling daily. I can't think of any other reason they would start discharging themselves in the off-peak period.

STORM WATCH!!!

We have a hurricane coming to town! I'm wondering if my storm watch mode will activate. I hope we don't get the hurricane of course, but if we do it'll be interesting to see if my powerwalls come in handy.