The Tesla Powerwall 2 is the battery that made home energy storage mainstream — 13.5 kWh in a wall-mounted box, AC-coupled so it retrofits onto almost any solar system. Years after launch it remains one of the most searched home batteries in America, and yes, Portlandia Electric Supply has genuine Powerwall 2 inventory (verified in stock, July 2026). This guide covers the real specs, what a full installation actually costs, what the battery will and won't run, and when one Powerwall isn't enough.
Powerwall 2 specifications (the definitive table)
| Specification | Powerwall 2 |
|---|---|
| Usable capacity | 13.5 kWh |
| Continuous power | 5 kW (7 kW peak, short-duration) |
| Chemistry | Lithium nickel manganese cobalt (NMC) |
| Coupling | AC-coupled (works with any existing solar inverter) |
| Round-trip efficiency | ~90% (AC to AC) |
| Dimensions | ~45.3 in x 29.6 in x 5.75 in |
| Weight | ~251 lbs (114 kg) |
| Mounting | Wall or floor, indoor or outdoor (IP67-rated enclosure) |
| Warranty | 10 years, 70% capacity retention, unlimited cycles (solar self-consumption/backup use) |
| Required companion | Tesla Backup Gateway 2 (system controller) |
The 5 kW continuous figure is the number that shapes every Powerwall 2 design conversation: it runs essentials comfortably, but not everything at once.
What a Powerwall 2 actually runs (and for how long)
Runtime = 13.5 kWh divided by your load. Realistic continuous draws:
| Load | Typical draw | Runtime on one Powerwall 2 |
|---|---|---|
| Refrigerator + lights + Wi-Fi + phone charging | 300–500W | 27–45 hours |
| Essentials + furnace blower (gas heat) | 600–900W | 15–22 hours |
| Essentials + window AC (5k BTU) | 1,200–1,800W | 7.5–11 hours |
| Above + well pump cycling | 1,500–2,500W average | 5–9 hours |
| Central AC (3-ton, ~3.5 kW) | 3,500W+ with 3x startup surge | 3–4 hours IF the surge doesn't trip it |
| Electric range or EV charging | 5–11 kW | Not realistic on one unit |
With solar recharging during the day, "runtime" extends indefinitely for loads under ~1 kW average — the battery bridges nights and cloudy stretches. That essentials-plus-solar configuration is the sweet spot for a single Powerwall 2.
Worked example: overnight backup for a 3-bedroom home
Critical loads panel: fridge (150W average), furnace blower (400W when running), 10 LED circuits (150W), networking and devices (100W) — call it 600W average overnight. One Powerwall 2 carries 13.5 / 0.6 = 22.5 hours of overnight and storm coverage. Add a 5 kW solar array producing 20 kWh on a decent day and the home runs indefinitely on sunshine plus battery, with the grid as a convenience rather than a lifeline.
Worked example: whole-home backup (two units)
Whole-home means surviving the surge: a 3-ton AC's locked-rotor startup can demand 9–12 kW momentarily. Two Powerwall 2 units deliver 10 kW continuous / 14 kW peak, which handles central AC starts on most homes with soft-starters, plus everything else. Two units require the Tesla Multi Powerwall Stacking Kit (1112154-00-B) — $424.23 at PES — for clean side-by-side installation.
What Powerwall 2 costs installed (2026)
Budget the full system, not the sticker:
- Battery: Tesla Powerwall 2 — 13.5kWh, $10,500 at PES (catalog price, July 2026).
- Gateway (required): Tesla Backup Gateway 2, $1,259.95 — the system controller that islands your home during outages.
- Installation: typically $2,000–$4,500 depending on panel work, permits, and region.
- Realistic installed single-unit total: roughly $14,000–$17,000 before incentives; the 30% federal residential clean energy credit (where applicable to your tax situation and current law) changes the math materially.
For load-level control — deciding which circuits the battery feeds in an outage — a smart panel like the Lumin Smart Panel (indoor unit, 12 circuits) at $3,920.59 adds circuit-level management without a full panel replacement.
Powerwall 2 vs. Powerwall 3 (honest context)
Tesla's newer Powerwall 3 integrates the solar inverter and posts higher continuous power (~11.5 kW). The Powerwall 2's case in 2026: it's the retrofit answer — AC-coupled, so it bolts onto any existing solar system without replacing the inverter, with a decade of field history behind it. If you already have solar and a working inverter, Powerwall 2 adds backup with minimal surgery. If you're designing a new system from scratch, compare both architectures before committing.
Three operating modes that pay the battery back
A Powerwall isn't only an outage insurance policy — its software modes decide the daily economics:
- Self-consumption (self-powered): solar charges the battery by day; the battery runs the house at night. In areas with weak net-metering export rates, this turns 8-cent exported kWh into 30-cent avoided retail kWh — the strongest everyday payback case.
- Time-based control (load shifting): charge from solar or off-peak grid, discharge through the 4–9 p.m. peak window. On time-of-use rates with a 2–3x peak/off-peak spread, a single unit shifting 8–10 kWh daily can save $600–$1,200 per year.
- Backup reserve: hold a set percentage (commonly 20–50%) for outages while the rest cycles daily. Storm-watch mode automatically tops the battery to 100% when severe weather threatens your area.
The practical configuration for most owners: time-based control with a 20–30% backup reserve — daily savings with a real outage cushion. Pure backup-only use wastes the asset 360 days a year.
Installation requirements most quotes gloss over
A Powerwall 2 install is more than hanging a box. The site needs: wall or floor space with clearances (the unit is ~251 lbs — structural mounting matters), a backed-up loads panel or whole-home configuration behind the Gateway, internet connectivity for monitoring and updates, and permits covering both electrical and (in many jurisdictions) fire code review of battery placement. Garages and exterior walls are the common locations; clearances from windows, doors, and ignition sources follow the install manual and local code. Budget one to two install days for a single unit with existing solar, plus inspection.
Frequently asked questions
How much does a Tesla Powerwall 2 cost?
The battery itself is $10,500 at Portlandia Electric Supply (catalog, July 2026), plus the required Backup Gateway 2 ($1,259.95) and installation — typically $14,000–$17,000 all-in for a single unit before incentives.
How long will a Powerwall 2 power my house?
For essentials (fridge, lights, internet, furnace blower) figure 15–45 hours depending on loads. With daytime solar recharging, a single unit can sustain an efficient home indefinitely.
Can a Powerwall run central air conditioning?
One unit, marginally — 5 kW continuous is borderline against a 3-ton compressor's startup surge. Two units (10 kW continuous) handle central AC on most homes, especially with a soft-starter fitted.
Is Powerwall 2 still available in 2026?
Yes — and PES has verified inventory, plus the Gateway 2 and stacking kits for multi-unit installs.
Does Powerwall 2 work off-grid?
It works with grid-forming inverters in off-grid-capable configurations, but it's designed first for grid-tied backup. For purpose-built off-grid systems, see our off-grid solar system design guide and energy storage systems.
Get backup on the wall
Powerwall 2 units, gateways, and stacking kits are in stock at Portlandia Electric Supply — browse battery storage, energy storage systems, or solar battery backup systems for alternatives at other price points. Planning a two-unit whole-home install? Call the counter — we'll confirm inventory and line up the gateway and stacking hardware in one order.
