I did a test last week to see how much energy can be consumed from 2 powerwalls in case of power outage. My battery was at 100% (due to grid services event), and by the end of the day it was drained down to 5% (0% reserve in app yields 5% in portal). When the reserve reached 5% in portal, the powerwall stopped powering the house. I assume this might be the same behavior when there is power outage.
For those trying to figure out how much actual energy each powerwall can provide them during a power outage, here are the numbers.
2x Powerwall2:
- Energy provided from 100% -> 5%: 22.2 kWh (so 11.1 kWh per Powerwall)
- Energy consumed to recharge 4% -> 99%: 24.6 kWh
- Round-trip loss: 9.76%
What is interesting is that I am not getting the advertised 13.5 kWh usable battery energy. In theory, 95% energy with 5% single-trip loss should yield 12.18 kWh per Powerwall. So I am short of 1 kWh. I have been told that the Powerwall keeps 1 kWh of storage to avoid fully draining the battery which would require a technician visit to bring it back to life. Can anyone else confirm this?
For those trying to figure out how much actual energy each powerwall can provide them during a power outage, here are the numbers.
2x Powerwall2:
- Energy provided from 100% -> 5%: 22.2 kWh (so 11.1 kWh per Powerwall)
- Energy consumed to recharge 4% -> 99%: 24.6 kWh
- Round-trip loss: 9.76%
What is interesting is that I am not getting the advertised 13.5 kWh usable battery energy. In theory, 95% energy with 5% single-trip loss should yield 12.18 kWh per Powerwall. So I am short of 1 kWh. I have been told that the Powerwall keeps 1 kWh of storage to avoid fully draining the battery which would require a technician visit to bring it back to life. Can anyone else confirm this?