Charging from powerwall at night

[pauldebarro]

I have an 18.6 kW solar system with 3 Powerwall 2s (40.5 kWh stored power). We have just bought a Tesla Y and have a Tesla wall charger gen 3 installed. We only have 1 car which we recharge at night as it is not at home during the day (mon to fri). We want to use the Powerwalls to recharge the car.

We recently completed a trip and returned home with 36% car battery charge. We plugged in the wall charger and in the morning the car had recharged (42 kWh) yet the powerwalls were showing 78% charge. This looks like the car bypassed the powerwalls and recharged from the grid. That's not what we want. We want to recharge preferentially from the powerwall and avoid using the grid. We are not worried about draing the powerwalls as we produce enough solar during the day and export o daily average = 30 kWh.

We don't need to fully recharge the car as we can top up from solar during the weekend when the car is at home.

Any suggestions as to why our wall charger seems to be bypassing the powerwalls?

 

[jjrandorin]

You didnt say anything about what mode you have the powerwall in. If its in anything EXCEPT "self powered" (like in Time of use, and you also put in buy and sell prices etc) that would be why. Self powered will do what you want, however it will also prioritize using your own solar + powerwalls at all times, not just at night.

 

[pauldebarro]

You didnt say anything about what mode you have the powerwall in. If its in anything EXCEPT "self powered" (like in Time of use, and you also put in buy and sell prices etc) that would be why. Self powered will do what you want, however it will also prioritize using your own solar + powerwalls at all times, not just at night.

The powerwalls are in "self powered" mode.

 

[jjrandorin]

with what set as the reserve?

 

[pauldebarro]

95% self-powered, 5% backup

 

[pauldebarro]

The other odd observation is the following.
When not charging the app shows

But as soon ad I charge it shows home use as 0

 

[pauldebarro]

 

[pauldebarro]

What I expected was that when I charge the car, the home use would increase to reflect the car charge and power would be discharging from the battery to the house. That is not happening.

 

[XPlaidPowerwal]

1. check and make sure you have "charge only on solar" disabled on the vehicle.
2. go to vehicle charging on the powerwall settings and check to make sure the slider is set all the way to the left at "10% (for home use) and 90% for share with vehicle"
3. make sure grid charging is set to " No"

 

[pauldebarro]

When I go to vehicle charging in the tesla app, it doesn't have a slider option. See screen shot.

 

[XPlaidPowerwal]

unpair the charge on solar option

 

[pauldebarro]

Ok. It's now unpaired. The Vehicle charging screen has remained as before. I do not seem to have that slide bar option. Just to check I am doing this correctly,
Tesla app
Settings
Vehicle charging

I note under the settings/powerwall
Backup reserve: 5% backup, 95% self-powered
Self-powered
Grid charging, no

 

[XPlaidPowerwal]

Ok.
Lastly make sure schedule charging is off on your vehicle settings in the app.
See if this works tonight