How do I calculate watt-hours needed?

Multiply each device's average watts by the hours you need it, add them up, then add roughly 15 to 20% for inverter losses. For cycling loads like refrigerators, use the duty cycle rather than continuous running watts.

Is it better to buy a bigger power station?

Bigger costs more and weighs more, and the useful ceiling is set by what you'll actually carry and store. Expandable systems that accept add-on battery modules are often the better answer than buying maximum capacity upfront.

Can I run a space heater on a power station?

Briefly, at best. A 1,500 W heater empties a 1,000 Wh station in well under an hour. Resistive heating is the fastest way to drain a battery, and no realistic portable station provides meaningful heat for long.

How to Size a Portable Power Station

Q: What size power station do I need for a refrigerator?

Check the surge rating first — a fridge can demand several times its running watts for an instant, so a station with a 1,000 W surge rating may fail to start one that runs on 150 W. For runtime, a fridge cycling roughly a third of the time uses far less energy than its running watts suggest.

Updated 2026-08-15 · 6 min read

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Three specifications decide whether a power station does what you want. Getting any one wrong makes the purchase disappointing.

How do you size a portable power station?

Continuous watts — what the inverter delivers steadily. Determines what you can run at all.

Surge watts — the momentary peak it tolerates. Determines whether you can start motor loads.

Watt-hours — stored energy. Determines how long.

Step 1: list what must run

Be honest about necessities rather than listing everything you own.

Device	Typical running W
LED lights (several)	30–60
Phone charging	10–20
Laptop	50–100
Wi-Fi router and modem	20–40
CPAP (no humidifier)	30–60
CPAP (with humidifier)	70–120
Refrigerator (running)	150–250
Chest freezer (running)	100–200
Furnace blower	400–800
Sump pump	600–1,000
TV	60–150
Microwave	1,000–1,500
Space heater	1,500
Kettle / coffee maker	1,000–1,500

Step 2: continuous watts

Add the running watts of everything on simultaneously.

Fridge (200) + lights (50) + router (30) + laptop (60) + CPAP (50) = 390 W.

A station with 500 W continuous covers that. One with 300 W does not.

Heating appliances are the trap. A single 1,500 W kettle exceeds most portable stations' continuous rating outright, and even where it doesn't, it drains the battery in minutes.

Why do surge watts matter for a power station?

The number people skip, and the reason a station "won't run my fridge" despite adequate continuous watts.

Motors draw several times their running power for a fraction of a second at startup:

Load	Running W	Typical surge
Refrigerator	200	800–1,200
Freezer	150	600–1,000
Sump pump	800	2,400
Furnace blower (PSC)	600	1,800

Check the station's surge rating against the largest surge on your list, not against the running total. See starting watts vs running watts.

Note that surge ratings vary in honesty and duration between manufacturers. If a load is close to the limit, it's worth being conservative.

How many watt-hours do you need?

Multiply average watts by hours needed.

Use duty cycle for cycling loads. A refrigerator doesn't run continuously — it cycles, commonly on the order of a third of the time. So a fridge with 200 W running draws roughly 65 W on average, not 200.

A 12-hour outage:

Load	Avg W	Hours	Wh
Fridge (⅓ duty)	65	12	780
Lights	40	6	240
Router	30	12	360
Laptop	60	4	240
Phones	15	4	60
Subtotal			1,680
+18% inverter losses			~1,980

So roughly a 2,000 Wh station for that scenario — with a continuous rating above 390 W and a surge rating above about 1,200 W.

Add margin: batteries lose capacity in the cold, and usable capacity is slightly below nameplate.

What size power station for common needs?

Devices and lights only. 300–500 Wh, modest inverter. Covers phones, a laptop, lights, and a router through an evening.

CPAP overnight. 500–1,000 Wh depending on whether the humidifier runs — turning the humidifier off dramatically extends runtime, which is worth knowing. See CPAP and medical device backup.

Keep the fridge cold. 1,000–2,000 Wh, with surge headroom over 1,200 W. Note that a full fridge left closed holds temperature for hours on its own — you may need less than you think.

Furnace blower through a winter night. 2,000 Wh+, with surge over 1,800 W, plus a way to connect to a hardwired furnace. See battery backup for a furnace.

Multi-day outage. No portable station alone. You need solar recharging, a generator to recharge it, or both — see solar generator charging.

Practical guidance

Expandable systems often beat buying maximum capacity upfront. Add battery modules when you learn what you actually need.

Weight matters. A 2,000 Wh LFP station is heavy. If it needs moving, check the figure before buying.

Prioritize surge rating if any motor load is on your list. It's the spec that most often makes a station unusable for the job it was bought for.

LFP chemistry for backup use — longer cycle life and better tolerance of sitting charged. See LiFePO4 vs NMC batteries.

Keep it charged. Top up every few months so it isn't at 20% when you need it.

The current field, by class

Once the math gives you a watt-hour and surge target, match it to a class — the power station picks carry the full write-ups.

Product	Type	Best for	Capacity	Cycle life	AC output	UPS switchover	Weight	Solar input	Recharge (AC)	Warranty	USB
Jackery Explorer 1000 v2	1 kWh class	First power station — fridge, phones, lights and CPAP through an outage	1,070 Wh LiFePO4	4,000 cycles to 70%+	1,500 W continuous / 3,000 W surge	<20 ms	23.8 lb	400 W max	1.7 hr; 1 hr emergency mode	3 + 2 years	USB-C 100 W + 30 W, USB-A
EcoFlow DELTA Pro 3	Whole-circuit class	Backing up real circuits — furnace, well pump, kitchen — without fuel or permits	4,096 Wh LFP (expandable to 12 kWh/unit, 48 kWh system)	4,000 cycles to 80%	4,000 W at 120/240 V / 8,000 W surge	10 ms	113.5 lb (wheeled)	2,600 W max	0-80% in 50 min (multi-input to 7,000 W)	5 years	—
Bluetti Elite 200 V2	2 kWh class	Most capacity and battery longevity per dollar in the 2 kWh class	2,073.6 Wh LiFePO4 (automotive grade)	6,000+ cycles to 80%	2,600 W continuous / 3,900 W lifting mode	15 ms	53.4 lb	1,000 W max	0-80% in 1.1 hr	5 years	2× USB-C 100 W, 2× USB-A
Jackery Explorer 2000 Plus	2 kWh class	Starting at 2 kWh with a real expansion path	2,042 Wh LiFePO4 (expandable to 12 kWh/unit, 24 kWh paired)	4,000 cycles to ~70%	3,000 W continuous / 6,000 W surge	20 ms EPS	61.5 lb (wheeled)	1,400 W max	2 hr	3 + 2 years	—
Anker SOLIX C1000 Gen 2	1 kWh class	The 1 kWh class's strongest inverter and fastest recharge	1,024 Wh LFP	4,000 cycles to 80%	2,000 W continuous / 3,000 W peak	10 ms, all AC ports	24.9 lb	600 W max	100% in 49 min (UltraFast)	Not published at review time — confirm at purchase	USB-C 140 W max
Bluetti AC180	1 kWh class	The budget route to a serious 1 kWh station	1,152 Wh LiFePO4	3,500+ cycles to 80%	1,800 W continuous / 2,700 W lifting mode	20 ms	35.3 lb	500 W max	0-80% in 45 min turbo	5 years	USB-C 100 W, 4× USB-A, wireless pad
Goal Zero Yeti 1000 (LiFePO4)	1 kWh class	Solar-first recharging and Goal Zero's transfer-switch ecosystem	998.4 Wh LiFePO4	4,000 cycles to 80%	2,000 W continuous / 3,600 W surge	<15 ms	35.3 lb	900 W combined	0-80% in 0.8 hr	5 years	USB-C 140 W + 60 W + 2× 30 W
EcoFlow RIVER 3 Plus	Entry class	Desk UPS duty, camping, and finding out what you actually need	286 Wh LiFePO4 (expandable to 858 Wh)	3,000 cycles to 80%	600 W continuous (X-Boost 1,200 W)	<10 ms	10.4 lb	—	—	—	—

Where to go next

More in our generator and backup power guides.

Frequently asked questions

Check the surge rating first — a fridge can demand several times its running watts for an instant, so a station with a 1,000 W surge rating may fail to start one that runs on 150 W. For runtime, a fridge cycling roughly a third of the time uses far less energy than its running watts suggest.

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