What do you want to keep running?
Check the circuits that matter and set how many hours a day each one really runs. Appliances cycle — a furnace may only run four hours on a cold day, and a fridge cycles seven. These defaults are winter-typical; adjust them to your home.
Solar panels are included at no extra cost with your rental term. Each panel is 400W and generally produces about 80% of rated capacity (320W working).
Your circuits add up to 2,140 W on paper, but fridges, furnaces and pumps cycle independently — the inverter only has to carry about 1,395 W at any one moment.
The Sparxx GCB installation manual specifies a maximum continuous load of 12,000 W. Your realistic draw is within the GCB's continuous rating.
How long the house actually stays livable, using the hours per day each appliance really runs. Without any sun at all: 1.8 days.
Worst case only: every selected circuit running at the same time, nothing cycling off, until the battery is empty. Real homes never run this way.
With the 12-panel array recharging each day, backup stretches to about 5.5 days in winter.
The array could make 9.6 kWh, but the Sparxx Turbo Booster accepts 4.8 kWh of solar input per day — the extra capacity covers cloudy days.
Snow cover, shading, and long cloudy stretches change these numbers. Use the Solar Angle tab to set the tilt and aim that get the most out of the array.
The Booster Micro still covers the circuits that matter most
Of what you selected, the Micro can carry Refrigerator, Chest freezer, Furnace / blower, Sump pump, Lights & receptacles, Internet / router / Wi-Fi — about 7.2 kWh a day, roughly 1 days of backup. Food stays cold, the heat stays on, the basement stays dry, and the internet stays up — at $200/mo on a 12-month term.
It's the 240V circuits you added — well pump, water heater, range, dryer — that require a larger unit, not the outage itself.
Every Sparxx Booster measured against your exact selection. Pick the one you want on your application.
Sparxx Turbo Booster
Sustained split-phase power — well pump, water heater, range, and daily solar load shedding.
- Your circuits total 2,140 W, but realistically draw about 1,395 W at once — inside the 5 kW output.
- 16 kWh covers about 1.8 days of realistic household cycling — or 6.1 hours if every circuit ran nonstop.
- 12 free panels stretch backup to about 5.5 days in winter.
| Unit | Month-to-month | Yr 1 | Yr 2+ |
|---|---|---|---|
| Sparxx Booster Micro | $250/mo | $200/mo | $150/mo |
| Sparxx Turbo Booster | $400/mo | $350/mo | $200/mo |
| Sparxx Mega Booster | $500/mo | $450/mo | $250/mo |
- $700 install deposit covers the Sparxx Generator Control Box and sub-feed panel — fully refunded after 6 consecutive rental months.
- No deposit required if a Generator Control Box is already installed.
- Placeholder rental available at $75 per two weeks.
- Maintenance, transfer switch, and gas install: $0 — Sparxx owns and services every generator.
- Estimates only. Your final rate is confirmed on the rental agreement.
How battery sizing works
Battery capacity is measured in kilowatt-hours (kWh). Add up what each circuit draws in a day — a fridge cycling seven hours, a furnace blower four hours on a cold day — and you get your daily kWh. Divide battery capacity by daily use and you have days of backup. The calculator does this for you, including the surge motors make when they start and a real-world diversity factor for loads that never run at the same moment.
Not sure which circuits you need?
The Backup Guide asks eight quick questions and recommends a system category — battery, standby, portable, inverter, or solar — then hands your answers straight into this calculator. For heavy whole-home loads that exceed battery output, the generator sizing calculator shows when a Kohler LP standby is the right call.