Change in Powerwall Behaviour

[Country Boy]

Hi All

I have had a power wall 2 for nearly 4 years now. (original gateway).

Normally when it decides to charge itself from the grid, it charges at 3.6kW (16 amps).

Since Friday night/Saturday morning, it now charges at 5kW (21 amps)

Have others noticed a this change in behaviour?

As an aside, I see we can now turn off Charging from the Grid in the settings. I have missed this feature. In the old days there were three settings: Self Powered, Cost optimised, and balanced. The balanced used to run the house during off peak from the grid, but not charge the battery, a mode I miss. At least now I can re-create that mode with Timer based control and grid charging off.

E

 

[WannabeOwner]

Normally when it decides to charge itself from the grid, it charges at 3.6kW (16 amps).

Is it possible that was related to some other (heavy) load running at same time?

If my Car is changing at same time my PowerWall charging drops from 10AMPs to 6.5AMPs

P.S> I also have a difference in charging AMPs between "Just increase RESERVE to 100%" (lower) and "Scheduled charging from Grid" (Max AMPs)

 

[ringi]

Maybe Tesla have got the the Octopus Flux massage.....

 

[Country Boy]

Is it possible that was related to some other (heavy) load running at same time?

The Powerwall has occasionally charged at 5kW in the past but on the odd occasion only and not every day as it does now.

P.S> I also have a difference in charging AMPs between "Just increase RESERVE to 100%" (lower) and "Scheduled charging from Grid" (Max AMPs)

I have the original gateway, so no backup facility.

 

[Big Dunc]

I changed to Octopus Flux a week ago.
Before I did, it would charge off peak (if it thought it needed to) and then at peak time it would not allow any import until the next off peak.
Now with the Flux tarrif programmed, it charges in the off peak which is great. But then during the day it sits idle a lot of the time and allows grid import, saving itself for the evening peak where it matches the house load and therefore all PV is exported.
This means that I land up importing a fair bit during the day which I don’t want and even though from the start of the evening peak to the early morning off peak it is supplying the house load, it still normally makes it with over 50%? Spare. Any ideas on how to stop the day time import? I was thinking of fiddling the rates to make this more expensive and seeing if it stopped doing it?

 

[ringi]

Seems an export from battery in evening peak is needed. The battery should fully empty itself in the last minute of the evening peak.

 

[Big Dunc]

No, because then we would be drawing from the grid until the start of the morning off peak.
Ideally, it would dump a load into the grid during the evening peak, but keep enough to safely get through to the morning off peak without having to import between the two.
However, I think during install my powerwall was configured so that it could not discharge to grid. This was due to DNO restrictions (my PV inverters are also limited for the same reason). That doesn't bother me and does explain why in the evening peak the powerwall will match the house load and all PV is exported.

 

[Big Dunc]

So last night we had to charge the car for longer than the off peak period, so a certain amount of that came from the powerwall and some from grid.
That means that now at 08:00 the powerwall is down to 30%. Zero PV as it is heavy rain, but that is forecast to stop later and the PV will be able to put enough into the powerwall to get through until tomorrow's morning off peak. However, currently the powerwall is charging from the grid at a rate of 1 kW and costing me money. It clearly "wants" to get more in it for later, but it isn't going to need it and its just wasting money. I am thinking of just putting it into self powered mode as it is trying to be too clever and being counter productive. What are other people's thoughts on this.

 

[Big Dunc]

Update. About 20 minutes after posting the above, powerwall stopped importing and starting supplying the house load. Since then we have started making PV, which is now slightly above the house load and powerwall is absorbing the surplus.

 

[Dilly]

The behaviour I’d expect when a PW gets down to reserve level, is just to power the house load, though I’ve not got that outside of off-peak when it tops itself up anyway.
I use peak and super off-peak in my app settings. That doesn’t allow any “grey areas” for top up.
I had enough solar for the last few days to export more than I’d like but last night I had 82% at midnight and it filled to 98% from the grid by 02:45!
Even though it’s dull day there would have been enough to fill back up though I can stick in one of the cars Instead.
At least self-powered stops it being a lottery!

 

[Big Dunc]

My back up reserve is at zero%. During the winter a single powerwall doesnt quite have enough capacity for us and as we have very few power cuts I decided not to artificially limit it. In the summer the powerwall rarely drops down low anyway (the big car charge last night was very much a "one off" event.
Hopefully the second powerwall that I ordered a year ago will arrive sometime over this summer and I might then set a sensible reserve.

 

[Dilly]

My back up reserve is at zero%. During the winter a single powerwall doesnt quite have enough capacity for us and as we have very few power cuts I decided not to artificially limit it. In the summer the powerwall rarely drops down low anyway (the big car charge last night was very much a "one off" event.
Hopefully the second powerwall that I ordered a year ago will arrive sometime over this summer and I might then set a sensible reserve.

Two will definitely work wonders for you. Even on a bad day I don’t get below 40% summer or winter. You then have the flexibility to draw 10kWh from them.

 

[Big Dunc]

I am so so looking forward to getting the second one.

 

[WannabeOwner]

evening peak where it matches the house load and therefore all PV is exported

You have PV during evening peak at this time of year? My PV is "done" by 17:00 this time of year (well "yesterday", will be 18:00 today)

 

[Big Dunc]

Not very much. My panels are predominantly SE facing so they are also done. I have a few NW facing, but they don't ever generate much. I am about to have a few more installed on a flat roof, but it isn't a big roof, so won't improve things massively.