For a short power outage covering the fridge, lights, internet and phones, a 2kWh Jackery is enough. To keep a sump pump, furnace and fridge going through a day-long outage, plan on a 3.5kWh to 5kWh station with a transfer switch: the HomePower 3600 Plus for 120V circuits, or the Explorer 5000 Plus or HomePower 3600 Pro Max if you need 240V. Size it from your own loads using the method below.
Step 1: list what must stay on
Write down each essential appliance, its running watts (from the label, or amps x 120) and how many hours a day it actually runs. Two numbers come out of this:
- Peak watts: everything that could run at once, plus the start-up surge of the biggest motor. This sets the minimum AC output.
- Daily watt-hours: watts x hours for each item, added up. This sets the battery size.
For a fridge, use the yellow EnergyGuide label: kWh per year ÷ 365 gives watt-hours per day. A fridge rated 400 kWh a year uses about 1,100Wh a day.
Step 2: match capacity to the outage
We plan on 85% of rated capacity being usable: hours = Wh x 0.85 ÷ watts. Here is how long each station lasts at three steady household loads.
| Station | Capacity | Usable (x 0.85) | 150W (fridge, router, lights) | 300W (add furnace blower) | 500W (add more circuits) |
|---|---|---|---|---|---|
| HomePower 1000 Plus v2 | 1,024Wh | 870Wh | about 5.8 h | about 2.9 h | about 1.7 h |
| HomePower 2000 Plus v2 | 2,048Wh | 1,741Wh | about 11.6 h | about 5.8 h | about 3.5 h |
| HomePower 3000 | 3,072Wh | 2,611Wh | about 17.4 h | about 8.7 h | about 5.2 h |
| HomePower 3600 Plus | 3,584Wh | 3,046Wh | about 20.3 h | about 10.2 h | about 6.1 h |
| Explorer 5000 Plus | 5,040Wh | 4,284Wh | about 28.6 h | about 14.3 h | about 8.6 h |
Real loads cycle on and off, so a fridge that draws 150W when running averages far less. If your list says 4kWh a day and you want two days without sun, you need about 9.4kWh rated (8,000Wh ÷ 0.85). That is where expansion batteries come in: the 2000 Plus v2 expands to 12kWh, the 3600 Plus to 21kWh, the 3600 Pro Max to 21.5kWh (43kWh with two units) and the 5000 Plus to 60kWh. See which pack fits which station in the Jackery expansion battery guide.
Jackery for a sump pump
A sump pump is the load that most often decides the size. Two things matter:
- Start-up surge. The motor needs several times its running watts for a moment. Check the station's surge rating against it: 4,800W on the 2000 Plus v2, 7,200W on the HomePower 3000 and 3600 Plus, 14,400W on the 5000 Plus.
- Duty cycle. A pump only runs when the pit fills. As an example, a pump drawing 800W that runs 5 minutes in every hour uses about 67Wh an hour, or about 1,600Wh a day. In a storm it may run far more, so size for your wettest day, not an average one.
Check that your pump is 120V; most are. A 240V well pump needs a 240V source: the Explorer 5000 Plus, the HomePower 3600 Pro Max, or two 3600 Plus units linked with the Jackery Connector (see Can I connect two HomePower 3600 Plus units?).
Step 3: choose how it connects to the house
Extension cords work for a fridge and a lamp. To power hard-wired loads like a furnace blower, sump pump or well pump, you need a transfer switch installed by a licensed electrician, which also stops power feeding back onto the utility lines.
| Transfer switch | For | Notes |
|---|---|---|
| Manual Transfer Switch 120V 30A | HomePower 3600 Plus (Jackery also lists the original 2000 Plus); it does not name the HomePower 2000 Plus v2, so ask us to confirm before pairing them | Pre-wired, L5-30 inlet, wattmeters, indoor metal cabinet |
| Manual Transfer Switch 240V 50A | Explorer 5000 Plus; also 2000 Plus or two 3600 Plus with a parallel combiner | Pre-wired, CS6375 inlet, indoor metal cabinet |
| Smart Transfer Switch | Explorer 5000 Plus only | Automatic, switches within 20 ms, app control; Jackery arranges installation |
| Manual Transfer Switch for 3600 Pro Max | HomePower 3600 Pro Max only | Pro/Tran 2 double-throw selectors per circuit |
Whether you need one at all is covered in Do I need a transfer switch to use a Jackery for home backup? The 5000 Plus install is walked through in Jackery 5000 Plus transfer switch installation, and the HomePower line as a whole in Jackery HomePower for RV and home backup.
Recharging during a long outage
Solar is what turns a one-day battery into a week of backup. As a planning figure, a panel makes about its rated watts x sun hours x 0.75 in a day, so one SolarSaga 500 X puts back roughly 1,500 to 1,875Wh on a good day. The 3600 Plus takes up to 1,000W of solar and the 5000 Plus up to 4,000W.
Which Jackery for home backup
- Fridge, router, lights for an evening: HomePower 2000 Plus v2, expandable later.
- 120V essentials circuits through a transfer switch: HomePower 3600 Plus with the 120V 30A switch.
- 240V loads or whole-home backup: Explorer 5000 Plus or HomePower 3600 Pro Max. Compare them in 3600 Plus vs 5000 Plus and 3600 Plus vs 3600 Pro Max.
Browse the Jackery solar generator bundles to buy the station and panels together.