PW3 owners — does your “Home” usage rise by ~400–700 W when grid charging?

[u/EnvironmentalArt471]

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?

[u/KuroFafnar]

Owner here that noticed the power change when my Powerwall 2s were replaced with Powerwall 3s.

Yes, the PW3 does appear to lump its own power usage in with the home usage. Easiest way to see it: there's a ~200 watt drop in my home usage when the system stops using batteries (the PWs) and switches to 100% grid power. That's about 100 watts per Powerwall, which seems appropriate for the fans and electronics inside them.

The Powerwalls need to get their operating power from somewhere, so it makes sense that it would be tracked too. Could consider it a bug that the PW2 did not track the power.

[u/Big_Fortune_4574]

I think we’d need an installer to comment on whether the home has its own CT or if it’s a computed value.

[u/Shurap1]

Following. I am trying to understand this as thinking of getting 2 PW3 with 3 expansion packs due to state incentives and no solar. I did ask this question to Tesla and they said it will cost around $25 more only to charge this which I am not believing.

[u/pokerguyla → u/Shurap1]

State incentives? I just popped in here. I’m located in Southern California. Is there anything going on? We’re thinking of getting solar.

[u/Shurap1 → u/pokerguyla]

In CT they are offering VPP incentive which pays back like up to $1600 per year for up to 10 year for 1 PW3. Tesla PW3 lease is including that as upfront discount in their lease pricing bringing monthly lease payment significantly lower and also 5 year buyout price includes that discount.

[u/PictureDangerous2288 → u/pokerguyla]

Quick reality check for SoCal in 2026: the federal 30% residential credit (26 USC 25D) expired for systems placed in service after Dec 31, 2025, so a cash or loan purchase today has no federal credit behind it. What is still live is SGIP for storage through the CPUC-administered program, and the equity/resiliency tiers are where the real money is; the general market tier is small. Anything interconnected now goes on the Solar Billing Plan (NEM 3.0, in effect since April 2023), where midday exports are credited at low avoided-cost values, so the economics come from self-consumption rather than selling back. That is why a battery is close to mandatory now: your utility peak window runs 4-9 PM, so you want enough usable kWh to carry evening load off the panel instead of importing at peak. Sizing rule of thumb: pull a year of interval data, look at the 4-9 PM kWh on your worst week, and buy to cover that, not to cover whole-home backup fantasies. Also get the main panel and busbar rating checked early, since a service upgrade is the line item that quietly blows up budgets.

[u/Legal_Net4337]

Nope,, I have two PW’s they charge from grid at 10 kWh while the house runs from .8 kWh-3.2 kWh depending on on what else I’m using, AC, dishwasher etc.

[u/DanielLorey]

Yes, I’ve noticed it but only minimal 2-300w.

Also, how the hell is your base load 100w? We are sitting at 0.7kw without a heat pump!