PW3 owners — does your “Home” usage rise by ~400–700 W when grid charging?
Looking for some comparisons from other Powerwall 3 owners, particularly anyone who grid charges at high power.
My setup is a Powerwall 3 + Expansion Pack (27 kWh) with 8.46 kWp solar. I grid charge overnight on a cheap UK tariff, typically at around 10 kW.
I’ve been away this week, which gave me a good opportunity to look at the house’s true background consumption. With essentially just a fridge/freezer, router, a couple of hubs and standby loads running, Tesla has still reported around 10–11 kWh/day of Home usage.
I’ve noticed something interesting:
Powerwall idle: Home can be around 0.1 kW
Powerwall charging at ~10 kW: Home rises to around 0.5 kW, and I’ve seen periods around 0.5–0.9 kW
Powerwall discharging at 10.2 kW: I captured Home at only 0.3 kW
Tesla is definitely separating battery charging from Home consumption. For example, on one day I imported 31.7 kWh, of which Tesla allocated 28.6 kWh to Powerwall and 3.1 kWh to Home.
I’ve also now switched my combi boiler completely off to eliminate that as a possible load, i already had pre heat turned off and rearly use hot water as i have electric shower.
I’m wondering whether the additional few hundred watts during heavy grid charging is PW3 inverter/conversion loss, fans/thermal management or other auxiliary consumption, and whether Tesla includes some of this under Home — or whether this behaviour could indicate a CT/metering issue.
Could other PW3 owners check their live Home load immediately before grid charging starts and again while charging at high power?
I’d especially like to hear from anyone with PW3 + Expansion charging at around 10 kW. What increase in Home consumption do you see?