How long does it take to charge a portable power station?

Charge time comes down to one idea: how big the battery is, and how fast power can flow in. Wall outlets are fast, solar depends on the sun, and a car socket is slow.

The formula

Hours to charge ≈ battery Wh ÷ (charging watts × 0.8)

The 0.8 is a rule of thumb, not a law. A station can't take in its full rated input watts for the whole charge; some energy is lost as heat, and many slow down near full. We got 0.8 from the makers' own figures:

• EcoFlow's RIVER 2 Max 500 has 660 W max AC input and lists 0–100% in 60 minutes. That's 499 Wh in an hour, or about 76% of 660 W.
• EcoFlow's DELTA 3 Max Plus has 1,800 W AC input and lists 0–80% in 64 minutes. That's about 1,640 Wh in 1.07 hours, or about 85% of 1,800 W.

Wall outlet (AC): the makers' own times

Power station	Battery	AC charging (maker's figure)
EcoFlow RIVER 2 Max 500	499 Wh	0–100% in 60 min (660 W max input)
BLUETTI Elite 100 V2	1,024 Wh	80% in 45 min (1,200 W TurboBoost)
Anker SOLIX C1000	1,056 Wh	80% in 43 min; full in under an hour (1,300 W max input)
Jackery Explorer 1000 v2	1,070 Wh	1.58 hours; 1 hour in Emergency Super Charge mode
EcoFlow DELTA 3 Max Plus	2,048 Wh	0–80% in 64 min (1,800 W input)
EcoFlow DELTA Pro 3	4,096 Wh	1,800 W on a 120 V outlet; about 2.8 hours by our formula
Jackery Explorer 5000 Plus	5,040 Wh	3.5 hours

The DELTA Pro 3 time is our estimate, not EcoFlow's: 4,096 ÷ (1,800 × 0.8). Jackery's 1-hour time for the Explorer 1000 v2 is a separate fast mode; its standard figure is 1.58 hours.

Solar: it depends on the sun

A panel rarely gives its full label watts. Heat, sun angle, dust and clouds all cut it. EcoFlow says a 400 W panel fills the 2,048 Wh DELTA 3 Max Plus in about 6.4 hours. That's about 320 W, or 80% of the label, in good conditions. Plan on 70% to 80%.

Sun hours needed ≈ battery Wh ÷ (panel watts × 0.75)

Battery	200 W of panels	400 W of panels	800 W of panels
500 Wh	about 3.3 hours	about 1.7 hours*	—
1,000 Wh	about 6.7 hours	about 3.3 hours	about 1.7 hours*
2,000 Wh	about 13 hours	about 6.7 hours	about 3.3 hours

*Only if the station accepts that much solar. Check its max solar input. The RIVER 2 Max 500 takes up to 220 W, so a 400 W panel array charges it no faster than about 220 W. The Jackery Explorer 1000 v2 takes 400 W; the Anker C1000, 600 W; the BLUETTI Elite 100 V2 and DELTA 3 Max Plus, 1,000 W; the DELTA Pro 3, 2,600 W.

A "good sun hour" isn't every daylight hour. In winter, or under clouds, one day may not be enough. The calculator above shows how much a 400 W array could add in a day of 5 good sun hours.

Worked example: 1,056 Wh station, 400 W of panels

• Real panel output: 400 × 0.75 = 300 W
• Hours: 1,056 ÷ 300 = about 3.5 good sun hours

That's most of a sunny day's strongest sun. With 200 W of panels, it's about 7 hours, so it likely takes two days.

Car: slow but useful

A 12 V car socket supplies about 100 W on many stations. EcoFlow lists a 100 W max car input on the RIVER 2 Max 500. The DELTA Pro 3 lists 12 V at 8 A, which is under 100 W.

• Jackery lists 12 hours to charge the Explorer 1000 v2 by car.
• A 2,048 Wh station at about 100 W would take about 25 hours: 2,048 ÷ (100 × 0.8).
• The Explorer 5000 Plus lists no car charging.

So a car tops up a small station on a drive. It won't fill a big one. Some makers sell alternator chargers that charge much faster while you drive; they need to be installed in the vehicle.

Never idle a car in a garage to charge a station. The exhaust has carbon monoxide.

From a generator

A generator charges a station the same way a wall outlet does. The generator must supply the station's AC input watts plus whatever else is plugged in. For a station that draws 1,800 W to charge, use a generator with comfortably more than 1,800 running watts, or turn on the station's slower charge setting if it has one.

This is a common outage plan: run the generator outdoors for a couple of hours by day, then run the house's essentials quietly from the battery at night.

Why is mine charging slower than the spec?

• It's cold or hot. The RIVER 2 Max 500, for example, charges only between 32°F and 113°F.
• It's nearly full. Charging slows near 100%.
• Solar panels are shaded, hot or mismatched to the input voltage range.
• A slow-charge or quiet mode is on in the app.

If it won't charge at all, see power station not charging or solar panel not charging a power station.

If you charge from a gas generator, run it outdoors only, 20+ feet from the house, away from windows and doors. Read our carbon monoxide guide.