as stated I have two PW's...... I love the "charge from grid" option and it was one of my original enhancement requests when i got my system installed in 2018.... very happy to finally have this capability. Right now I have a foot of snow on my panels and no solar production. PW's down to 95% with vampire draw in a cold garage so I toggled to "grid charge". On the app they show that they are drawing/charging with 2.4kw from the grid. Is this expected behavior for two PW's in this situation? Thanks!
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What is PW's KW draw when charging from the grid? I have 2 PW's and they are charging at 2.4kw.
- Thread starter nyprepper
- Start date
With the variables of already at 95% charge, and cold batteries? Probably.
Mine only charge at 3.3kW from the grid, and they are in a Drywalled garage in Southern California that never goes lower than about 40 degrees at any point. I think there might be a setting somewhere in the powerwalls which controls this setting, but have never dug into it myself as I dont have a desire to change it.
Mine only charge at 3.3kW from the grid, and they are in a Drywalled garage in Southern California that never goes lower than about 40 degrees at any point. I think there might be a setting somewhere in the powerwalls which controls this setting, but have never dug into it myself as I dont have a desire to change it.
thank you @jjrandorin i expected the charge rate would be about twice that, I appreciate you sharing your insight and experience
No problem. FWIW, I am fairly sure that some peoples charge from the grid at higher levels, like up to 5kW each. Im not sure what the stipulations are on why its set the way it is. I thought about calling Tesla to see if they would up my grid charging speed from the 3.4kW I currently see, but did not know how receptive they would be to it.
i also admitted to myself that I dont "need" it to be faster, I just "wanted" it, just because... (of nothing other than it could go faster, lol)
@nyprepper Don't underestimate the impact of low temperatures on charging in general, but specifically charge rate. 2.4kW on a 95% full battery is pretty good, even for a warm battery. The peak charging currents tend to occur between 20-80% SoC.
I would trust the Powerwall on this; Tesla has millions of hours on charging their cells (cars & Powerwalls), and I suspect that the algorithms are pretty good at this point.
There is a thread elsewhere here on cold Powerwall operations and the benefits of some added insulation during low temperatures.
All the best,
BG
I would trust the Powerwall on this; Tesla has millions of hours on charging their cells (cars & Powerwalls), and I suspect that the algorithms are pretty good at this point.
There is a thread elsewhere here on cold Powerwall operations and the benefits of some added insulation during low temperatures.
All the best,
BG
My Powerwalls grid charge at 5.0kW each. Above 95% they do slow down. They also sometimes drop SOC from 100% to about 98% occasionally without actually discharging. I attribute this to battery balancing. They then charge back to 100% with low power. I have also observed lower charging power when it's relatively cold outside. Of course, this is SF Bay Area "cold" not New York cold.
You can read more about this in the following thread:
New Powerwall Advanced Options [Toggles for charging from and discharging to grid from powerwalls]
I didn't see a post covering this already, but looks like maybe we can charge from the grid now? https://www.tesla.com/support/energy/powerwall/mobile-app/powerwall-modes#advanced-settings
teslamotorsclub.com
Matt-FL
Member
I think it has changed in the US with one of the firmware updates.
The day after my system was installed (Aug 2022), we got a storm watch and my 4 PWs went immediately into grid charge mode. I was pulling 15kW from the grid, with 1.5kW going to the house and 13.5kW going to the powerwalls. (It fluctuated slightly with house usage, but grid was steady 15kW) It stayed like this until the PWs were at 100%. (On a side note, it wasn't really a big storm, but I wasn't able to turn off storm watch as my system hadn't been 'unlocked' after install. I texted one of the installers, and 15 minutes later, I had access to turn it off).
We are having bad storms today, so last night I enabled grid charging. The aggregate PW charge was steady at 7.75kW while the rest was going to whatever the house needed. The biggest difference was the tail-off once the batteries reached 90%. Charging slowly reduced kW until it was down to 5kW at 100%.
From Aug 2022:
I didn't grab a Tesla app screenshot last night, but I do have the Powerwall dash stats:
The day after my system was installed (Aug 2022), we got a storm watch and my 4 PWs went immediately into grid charge mode. I was pulling 15kW from the grid, with 1.5kW going to the house and 13.5kW going to the powerwalls. (It fluctuated slightly with house usage, but grid was steady 15kW) It stayed like this until the PWs were at 100%. (On a side note, it wasn't really a big storm, but I wasn't able to turn off storm watch as my system hadn't been 'unlocked' after install. I texted one of the installers, and 15 minutes later, I had access to turn it off).
We are having bad storms today, so last night I enabled grid charging. The aggregate PW charge was steady at 7.75kW while the rest was going to whatever the house needed. The biggest difference was the tail-off once the batteries reached 90%. Charging slowly reduced kW until it was down to 5kW at 100%.
From Aug 2022:
I didn't grab a Tesla app screenshot last night, but I do have the Powerwall dash stats:
charlesj
Active Member
Notice you have 4 PW so it is about 4kW per battery.
Not sure OP wanted total of all batteries at once or each battery. I think on my last Storm Watch it may have been 6kW total, 3 kW each.
Just connected mine to the grid a few minutes - first time in a long time overrode the STORM WATCH because in that mode it prioritizes keeping the Powerwalls at 100%, and the lights we flickering from a storm, so I took it off grid, no more flickering.
The storm passed, and I reconnected and our charge rate is 7.8kW.
The storm passed, and I reconnected and our charge rate is 7.8kW.
Matt-FL
Member
In 2022, it charged at ~ 3.375kW per powerwall.
In 2024, it is charging at ~ 1.9375kW per powerwall.
Perhaps it limits max draw now to 10kw, and fewer powerwalls would draw a higher kW each, but definitely a change was made to charge calculations in the last year or so.
It doesn't really bother me, I do trust that Tesla is doing the best calculations for me (and themselves) for longevity of the units.
quick update.... we had a grid outage last night and I woke up to PW's at 90% capacity. I switched to grid charging and the PW's started charging with 3.4kw (total) from the grid. As capacity neared 100% I observed that the draw rate from the grid tapered down gradually from 3.4kw to 2.3kw. Note- my PW's are in an insulated basement garage.... probably about 50f right now.
We’re on time of use rates, and the charge/use schedule is tied to that.
As mentioned, I checked this morning, weather is beautiful, and yes, “STORM WATCH” is still on, so I overrode that by taking the house off-grid.
Fortunately right now, low solar generation from winter’s low sun angle ever so slightly exceeds the house consumption (me sitting here on the computer and the internet routers), so the PWs are charging. Peak ends at 1100 local, and will switch back to “your regularly scheduled program."
As mentioned, I checked this morning, weather is beautiful, and yes, “STORM WATCH” is still on, so I overrode that by taking the house off-grid.
Fortunately right now, low solar generation from winter’s low sun angle ever so slightly exceeds the house consumption (me sitting here on the computer and the internet routers), so the PWs are charging. Peak ends at 1100 local, and will switch back to “your regularly scheduled program."
GregBallantyne
Member
I've got 3 PWs, and my observation is that when charging from grid by changing the self powering percentage the flow is always 5.8 kw. I don't believe I've seen variation from that. When charging from grid when Stormwatch is in effect, it's usually 12 kw. When charging from solar generation, I've seen it higher, in the 15-16 kw range. I would think any single PW could take in the same as it can put out? Which I think is 5.8 kw. That lines up with the highest flow into them I've observed, which isn't far off of the total rating of the two inverters. Not sure what limits the other cases.
BTW, my PWs are in the basement, always 58-68 F.
BTW, my PWs are in the basement, always 58-68 F.
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Mine charge above 5kW each for some reason. Kind of a problem given that I have 200A service and also have 20+kw of Tesla charging. Have to aggressively do time management on everything.
eml2
Member
I think the charge from grid rate depends on the mode.
I have 2 PW2. In self-powered, charging from grid is ~3.3 kw total. That turns out around 10% per hour. When storm watch is active, it doubles the rate to ~6.6 kw. In Time Based Control, I have seen it charged at 10 kw (i.e. max for 2 PW).
I have 2 PW2. In self-powered, charging from grid is ~3.3 kw total. That turns out around 10% per hour. When storm watch is active, it doubles the rate to ~6.6 kw. In Time Based Control, I have seen it charged at 10 kw (i.e. max for 2 PW).
jhn_
Member
I second these observations on our PW2s. We see the same numbers now. A few years ago when they we installed though it was always about 5kw per PW regardless of mode.
Interesting, I'm in UK also and get 3.6kW (the supplier limit in and out unless permission gained from the DSO) in time based mode and 1.7kW in self-powered. So curious @bruce_miranda that you see 2.34kW, what firmware version are you on?
