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The power station by the tent runs dry before the phones are charged, and the panel on the ground looks too small for the job. A solar charger calculator answers the size question before buying: add up the watt-hours the gear needs each day, divide by the hours of sunlight, and match the result to a panel with enough watts. The steps below show how to work it out from the listing figures.
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How a solar charger calculator works
A solar charger calculator turns daily energy use into panel watts. Start with the watt-hours the gear needs in a day, divide by the hours of sunlight, and the result is the panel watts that cover the need. The Renogy listing shows the shape of the answer: its 200W kit lists up to 1000Wh per day with 5 hours of sunlight, so 1000 divided by 5 is 200. The calculator sits between those figures: the loads decide the watt-hours, and the watt-hours decide the panel.
Step 1: Add up the daily watt-hours
List the gear to charge and the watt-hours each piece needs in a day, then add them together. A phone, a laptop, a fridge and lights each add their own figure, and the total is the daily need the panel must cover. Read the watt-hours off the device label or manual, and write the figure next to each piece of gear. A panel that cannot cover the daily total leaves the battery short by nightfall, so the total is the floor for the whole calculation.
Step 2: Divide by the hours of sunlight
Take the daily watt-hours and divide by the hours of sunlight the panel gets. The Renogy listing gives the pattern: up to 1000Wh per day with 5 hours of sunlight from a 200W panel. A site with fewer hours of sunlight needs a bigger panel for the same daily total, and a site with more hours needs a smaller one. Use the hours the panel actually gets, with nothing shading it, and not the hours of daylight on the longest day.
Step 3: Check the panel and the controller
Match the panel watts to the result, then check the controller and the cable. The Renogy kit (on Amazon) includes a 20A charge controller for 12V batteries and power stations, with MC4 output cables only, and the 4-in-1 adapter cable is sold separately. The Movsunpv panel (on Amazon) has a 4-in-1 cable with XT60, DC5521, DC7909 and Anderson connectors, and no controller is included. Check that the panel voltage and the controller current fit the battery: the Renogy controller is rated 20A for a 12V battery, so a battery of another voltage needs a controller rated for it. See the solar charge controller size guide for how to match a controller to a panel.
Step 4: Check the panel size and weight
A foldable panel has to fit the space it travels in. The Movsunpv measures 27.36 by 1.77 by 30.94 inches and weighs 16.09 pounds, and the Renogy measures 34.25 by 1.57 by 22.83 inches and weighs 28.46 pounds. The Movsunpv has 4 reinforced adjustable kickstands, and the Renogy has an adjustable aluminum alloy kickstand. A foldable panel fits a kit that moves often, and a lighter panel suits the same kit.
The panels for this job
The sizing steps above need a panel with a stated watts figure and, where the kit includes one, a controller with a stated current. The panels below cover the calculation, from a 100W foldable kit to a 200W kit with a 20A controller.
| # | Product | Solar Score | Buy |
|---|---|---|---|
| 1 |  Renogy 200W Portable Kit | 9.7/10 | Buy on Amazon |
| 2 |  Movsunpv 200W Foldable Kit | 9.6/10 | Buy on Amazon |
| 3 |  DOKIO 200W KIT | 9.6/10 | Buy on Amazon |
| 4 |  DOKIO 100W Foldable | 9.6/10 | Buy on Amazon |
Renogy 200W Portable Kit
A 200W foldable N-Type kit with a 20A controller and tempered glass, for the panel-size step of the calculator.
Pros
- 25% efficiency stated for N-Type cells
- 20A charge controller included for 12V batteries and power stations
- Up to 1000Wh per day with 5 hours of sunlight stated
- 5-year materials and workmanship warranty stated
Cons
- 4-in-1 adapter cable is sold separately
- 28.46 pounds, heavier than the 16.09 pound Movsunpv
- MC4 output cables only, with no other connector in the box
Detailed Review
The listing states a 200W foldable N-Type panel with 25% efficiency, a 20A charge controller for 12V batteries and power stations, tempered glass and an aluminum alloy kickstand. It lists up to 1000Wh per day with 5 hours of sunlight, an IP65 junction box, and MC4 output cables only. The bullets say a 5-year materials and workmanship warranty, while the spec table says a 3-year output and material and workmanship warranty. It weighs 28.46 pounds and measures 34.25 by 1.57 by 22.83 inches.
Who it's for: owners who want a 200W foldable kit with a controller and tempered glass for an RV or a power station. Who should skip it: anyone who needs the 4-in-1 adapter cable in the box or a lighter kit.
Its Solar Score of 9.7/10 comes from performance 32/35, build 22/25, value 21/25, safety 8/10 and warranty 3/5: 86 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Panel | 200W, N-Type, 25% efficiency |
|---|---|
| Controller | 20A charger controller, 12V |
| Daily output | Up to 1000Wh with 5 hours of sunlight |
| Weight | 28.46 lb |
Figures as published on the retailer listing, collected 12 November 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. IP65-rated junction box, tempered glass and anti-corrosion aluminum frame stated, so safety scores 8 of 10. 5-year materials and workmanship warranty stated. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
Movsunpv 200W Foldable Kit
A 200W foldable N-Type panel with 25% efficiency and a 4-in-1 cable, for the panel-size step of the calculator.
Pros
- 25% efficiency stated for N-Type cells with 16 busbars
- 4-in-1 cable with XT60, DC5521, DC7909 and Anderson connectors
- 4 reinforced adjustable kickstands stated
- Lightweight aluminum frame stated
Cons
- No warranty term is stated
- No charge controller is included
- No daily watt-hours figure is stated
Detailed Review
The listing states a 200W foldable N-Type panel with 25% efficiency, 16 busbars, a lightweight aluminum frame and a 4-in-1 cable with XT60, DC5521, DC7909 and Anderson connectors. The title says IP65 while the bullets say IP67, and the listing says the 4 kickstands angle the panel 45 degrees to capture 30% more sunlight than flat laying. It weighs 16.09 pounds and measures 27.36 by 1.77 by 30.94 inches. No warranty term is stated.
Who it's for: owners who want a 200W foldable panel with a 4-in-1 cable for a power station or an RV setup. Who should skip it: anyone who needs a stated warranty term or a charge controller in the kit.
Its Solar Score of 9.6/10 comes from performance 30/35, build 21/25, value 20/25, safety 7/10 and warranty 0/5: 78 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Panel | 200W, N-Type, 25% efficiency |
|---|---|
| Cable | 4-in-1: XT60, DC5521, DC7909, Anderson |
| Size | 27.36 x 1.77 x 30.94 in |
| Weight | 16.09 lb |
Figures as published on the retailer listing, collected 12 November 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. IP65 stated in the title and IP67 stated in the bullets, with an ETFE coating stated, so safety scores 7 of 10. No warranty term, so warranty scores zero. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
DOKIO 200W KIT
A 200W foldable kit with a separate PWM controller, 9.84 ft cable and dual USB ports.
Pros
- 200W foldable at 9.7 lb
- Separate controller replaceable or upgradeable
- 9.84 ft cable plus SAE, XT60 and alligator clips
- Dual USB ports for phones and small gear
Cons
- Controller amperage is not stated
- No efficiency figure is stated
- No UL, ETL, CSA, FCC or IP rating is stated
Detailed Review
DOKIO lists a 200W foldable monocrystalline panel with a separate PWM controller, 18V max and 6.1A. The controller protects against reverse polarity, overcharge, overload and short circuit, and the listing says it can be replaced or upgraded later. A 9.84 ft cable is included, along with SAE, XT60 and alligator clips, DC connectors and dual USB ports. It folds to 20 by 27 by 1.1 inches and weighs 9.7 pounds. The spec table lists a maximum power of 220 watts against the title's 200W; trust the title and bullets. The listing asks buyers to check their power station's input cap, for example 100 to 150W. Warranty is 1 year.
Who it's for: buyers who want a light 200W folder with a swappable controller. Who should skip it: anyone who needs a stated efficiency figure.
Its Solar Score of 9.6/10 comes from performance 29/35, build 20/25, value 21/25, safety 8/10 and warranty 3/5: 81 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Wattage | 200W |
|---|---|
| Controller | PWM, separate |
| Folded size | 20 x 27 in |
| Weight | 9.7 lb |
Figures as published on the retailer listing, collected 19 October 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. Controller protections stated: reverse polarity, overcharge, overload, short circuit, so safety scores 8 of 10. 1 year. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
DOKIO 100W Foldable
A 100W foldable kit with a separate PWM controller, dual USB and a 1-year warranty.
Pros
- Separate PWM controller with 4 protections stated
- Dual USB ports stated
- 9.84ft cable stated
- 1-year warranty stated
Cons
- Title says 5.3 lb while bullets say 6 lb
- No efficiency figure is stated
- Heavier than the 60W examples
Detailed Review
The listing states a 100W foldable panel for 12V battery charging with a separate PWM controller covering reverse polarity, overcharge, overload and short-circuit, dual USB ports, and a 9.84ft cable. The title states 5.3 lb while the bullets state 6 lb, so the listing contradicts itself on weight. The spec table lists 110W maximum power against the 100W title, so the title wins. The listing states a 1-year warranty.
Who it's for: shoppers charging 12V batteries who want a separate controller. Who should skip it: anyone who needs the lightest 100W panel.
Its Solar Score of 9.6/10 comes from performance 28/35, build 20/25, value 20/25, safety 7/10 and warranty 2/5: 77 of 100 points, placed on our 9.2 to 9.8 scale.
Key Specifications
| Power | 100W, 18V |
|---|---|
| Controller | Separate PWM stated |
| Cable | 9.84 ft |
| Warranty | 1 year |
Figures as published on the retailer listing, collected 22 October 2026. Performance figures are manufacturer rated.
Safety and Warranty
What this listing states. PWM controller with reverse polarity, overcharge, overload and short-circuit protection stated, so safety scores 7 of 10. 1 year warranty stated. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 2 of 5. See How We Pick.
Panels make voltage in daylight. Keep connectors covered until you connect them, check the panel's stated open circuit voltage and current against your controller or power station input limits, and use cables rated for the current. Roof and permanent mounts belong to a qualified installer.
This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.
As an Amazon Associate I earn from qualifying purchases.
Ways to get more from the panel
- Angle the panel toward the sun: the Movsunpv kickstands angle the panel 45 degrees, and the listing says that captures 30% more sunlight than flat laying.
- Keep the panel face clean and unshaded, so the output stays near the listed figure.
- Match the cable to the power station: the Movsunpv 4-in-1 cable covers XT60, DC5521, DC7909 and Anderson, while the Renogy has MC4 output cables only.
- Use the controller the kit includes, and check the manual for the battery voltage it fits.
FAQ: power away from the grid
What size solar panel charges a power station?
Add up the watt-hours the station must replace in a day, then divide by the hours of sunlight. The Renogy 200W kit lists up to 1000Wh per day with 5 hours of sunlight, which shows how the figures line up for a 200W panel.
What size solar panel fits a 12V battery?
Work out the daily watt-hours the battery must give, then divide by the hours of sunlight to get the panel watts. The Renogy kit pairs a 200W panel with a 20A controller for a 12V battery, so the controller current and the battery voltage are the figures to match.
Does a solar panel work on cloudy days?
Yes, with lower output. The Movsunpv listing says its panels still function on cloudy days or in shaded areas, but the output power is lower than in direct sunlight. A bigger panel covers the same daily total with fewer hours of direct sun.
What is the difference between a 100W and a 200W solar panel?
The watts figure is the panel output in full sun. A 200W panel lists a higher watts figure than a 100W panel, so it covers a bigger daily total in the same hours of sunlight. The DOKIO listings show the pair: a 100W foldable kit and a 200W foldable kit, each with a controller.
Related solar guides
See the solar generator calculator, the size of inverter for solar power, the solar charge controller size and the DIY solar panel kits.
