Quick answer: Goal Zero publishes the honest figure and nobody quotes it: 9 to 18 hours of sunlight to recharge a power station of 1,516 Wh from one 200 W panel. That is not one day. And the wall charger in the box takes 14 hours.
Past about a day, capacity stops being the question. We said so working out what a 2,000 Wh station covers: size for the refill, not the battery. This is the refill. Every page on it says “solar panels” and stops, so we copied out what five manufacturers publish. For the wider decision, our power station sizing guide covers every tier.
What the makers publish about how you recharge a power station
Five units, three ways in. Two of the five do not publish a solar recharge time at all.
| Unit | Capacity | Max solar input | Published solar refill | Published wall refill |
|---|---|---|---|---|
| Goal Zero Yeti 1500X | 1,516 Wh | 600 W | 9–18 hours of sunlight on 200 W of panel; 18–36 on 100 W | 14 h on the supply included; 7 h and 3 h on paid ones |
| Jackery Explorer 1500 | 1,536 Wh | 400 W | not published | not published |
| BLUETTI AC70P | 864 Wh | 500 W | about 2 h on “a continuous input of 500W” | 80 % in 45 min on Turbo |
| Jackery Explorer 600 v2 | 640 Wh | 200 W | not published | not published |
| EcoFlow RIVER 2 | 256 Wh | 110 W | 3 to 6 h | 1 h |
The third column is the one to shop on and the one nobody compares. It is a ceiling set by the machine, not by your panels: watts above it do not go in. Across these five it varies by a factor of five and a half.
“Hours of sunlight” is not hours of the day
Goal Zero’s wording is precise and almost everyone reads past it. Not 9 to 18 hours: “9-18 hours of sunlight”. Those are panel-hours at useful output, and a winter day does not contain many of them. A storm big enough to take your power out is not a bright still morning either.
Do the naive division and 1,516 Wh over a 200 W panel is 7.6 hours. Goal Zero’s own range starts above that and ends at nearly two and a half times it — the maker telling you what a panel delivers against its rating. We will not convert that into days: it depends on your latitude, your month and your cloud, and none of the five publishes any of them. What we will say is that one 200 W panel is not a day’s work on a 1.5 kWh unit, and that you are drawing from the battery while it charges.
BLUETTI is the honest counterpart. Its two-hour figure is real, and its own next sentence is the caveat: the time “may vary based on weather conditions, sunlight intensity, panel orientation, and other variables”. Two hours is what 500 W continuous buys. Nothing on the page says how often you get 500 W continuous.
The charger in the box is the slow one
Multi-day outages are rarely a clean line. The grid comes back for an hour at three in the morning and goes again, and what you capture in that window is decided by the power supply that shipped with the unit.
Goal Zero publishes all three options against the same battery: 14 hours on the 120 W supply in the box, 7 on a 230 W supply sold separately, 3 on a 600 W one. An hour of grid on the included brick is about 120 Wh, 8 per cent of the battery. On the 600 W supply that hour is nearly two fifths of it. A purchase decision made before the outage, and not the capacity.
At the small end EcoFlow does the opposite: the RIVER 2 is published as fully charged from the wall in one hour on the cable supplied, against three to six on solar. For a unit that size the wall is not the slow option, it is the fast one.
The two ways this fails, and neither is the battery
The car looks like the obvious backstop and is the weakest of the three. EcoFlow publishes 100 W for its car input; Jackery publishes 11–16 V at 8 A. At those rates a 1,500 Wh unit is a long evening of engine running for one refill. EcoFlow attaches a warning worth repeating: use the car charger “after the vehicle is started”, so you do not flatten the battery you need to start the car.
The second failure is quieter. Several of these publish a charging floor of 32 °F (0 °C), and below it the battery management system declines rather than charging slowly. A February outage with the unit in an unheated garage is exactly the case where you have panels, sun and no way in. Where that limit sits on each product is in freezing temperatures, and it is the argument for keeping the machine in the house.
How we read this
Capacities, input ceilings and every recharge time above are quoted from the manufacturer’s own product page or manual, linked in the table and read on 7 September 2026. The only arithmetic of ours is 1,516 divided by 200, and it is labelled as ours. Where a document gives no figure we wrote “not published”.
None of the five publishes what a panel delivers against its rating, or how many usable hours of sun a day contains. That is the gap between the table and a plan, and we are not filling it with a number nobody stands behind. Note too that a station never delivers its rated capacity at the socket, which usable capacity works through, and that the loads running while it charges are the other half of the sum, in the 1,000 Wh runtimes. No product was tested by us and none is recommended. Our method is at how we test.
Two things not to improvise
Charging from a car means running the engine, and an engine must never run in a garage or any enclosed space, doors open or not. The same goes for charging from a fuel generator: the generator stays outside and well away from windows and vents. That is a carbon monoxide rule, not a ventilation one.
Match your panels to the input limits your own manual prints — both the watts and the open-circuit voltage. Never feed a house through a wall socket; that is backfeeding and it can kill line workers. A transfer switch is electrician work.
Frequently asked questions
How do you recharge a power station in a long power cut?
Three published routes: solar, the wall when the grid returns, and a car or generator outlet. Solar is the only one needing neither grid nor fuel, and it is the slowest: Goal Zero publishes 9 to 18 hours of sunlight for one refill of 1,516 Wh on 200 W of panel.
How many watts of solar panel can I connect?
Whatever your manual prints as the maximum solar input, and no more. Across these five it runs from 110 W to 600 W. Anything above it is capacity you paid for and cannot use, and the open-circuit voltage limit matters as much — BLUETTI names 58 V for the AC70P.
Can I charge it from my car?
Yes, and it is the slowest of the three: EcoFlow publishes 100 W for its car input, and says to connect it only after the engine is running so the car still starts. Never run an engine in a garage or any enclosed space.
Will it charge in freezing weather?
Several publish a charging floor of 32 °F and refuse below it, whatever the panels are doing. Discharging usually carries on lower, so a cold station runs your loads and will not refill. Keeping it indoors solves this for nothing.
The short version
Read the maximum solar input before buying a panel, and the wall charger’s rating before assuming an hour of grid is worth having. Then read the maker’s solar figure as what it says: hours of sunlight, not hours. On the one unit whose maker publishes all three routes, the fast wall supply is an extra purchase.
This article is general information, not an installation guide and not a substitute for a licensed electrician. Electrical work on a service panel, a transfer switch or a utility connection is regulated in most jurisdictions and normally requires a permit and an inspection. Fuel-burning equipment produces carbon monoxide and must never be run indoors, in a garage or near an opening into the home.
