RV Solar Power: How Much You Need for Full-Time RV Living

Last updated: October 13, 2026 | By Chuck Price | 14 min read

A full-time couple using 1,870 Wh a day needs about 510 to 830 watts of solar in a Phoenix December, plus about 365 amp-hours of lithium for two days of storage. The same load needs only 297 watts in June. Size for your worst month and add alternator charging.

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Chuck Price has RVed for more than 35 years and CBC Radio’s “Cost of Living” has featured him. He and his wife Cindy travel in a 2018 Hymer Aktiv Class B with two 300 Ah lithium batteries, 250 watts of roof solar and a 280-amp underhood alternator.

How much power does your RV use each day?

Your daily watt-hours are the one number every other choice depends on. Panels, battery and inverter are all sized from it, and guessing it wrong breaks the whole design. The figures below apply to 12-volt house systems in vans, Class Bs and small trailers, not to rigs running roof air conditioning on battery. For one example, Dometic rates its CFX3 45 compressor fridge at 490 Wh per 24 hours on its spec sheet.

Daily Wh = watts x hours of use, added up for every device. Then add the loads people forget:

• Fridge: the CFX3 45 rating is 490 Wh a day at Dometic’s “DC@5/25°C” test point. Dometic does not define that condition on the page, so measure your own fridge in the heat you camp in.
• Inverter idle: Victron lists 10 watts of zero-load draw for its Phoenix 12/1200 inverter.
• Ten watts of idle draw for 24 hours costs 240 Wh a day before you run a single appliance.
• That idle draw is about 13% of the 1,870 Wh full-time couple profile below.
• Parasitic loads: propane detectors, stereo memory and USB chargers left plugged in.

Guess less and measure more. A shunt-type battery monitor records every amp-hour in and out of the bank. Run your normal routine for a week and read the daily total. That week of data replaces every estimate in this article.

The Victron BMV-712 in our Hymer counts what goes in and out of the bank. Voltage alone does not tell you that.

How much solar do you need, and in which month?

Size your RV solar array for the month with the least sun, not the most. Panel output follows the season, and a summer-sized array runs short when the days get short. This applies most to snowbirds and full-timers who stay out from November through February. The U.S. Department of Energy notes that “Denver, Colorado, (near 40° latitude) receives nearly three times more solar energy in June than they do in December” in its Solar Radiation Basics explainer.

Array watts = daily Wh / (peak sun hours x 0.75). One peak sun hour equals 1 kWh of sunlight per square meter. The 0.75 is our planning allowance for heat, dust, wiring and charge losses. It is an assumption, not a published constant.

NREL’s station data shows how much the month matters. These are monthly averages from the NREL Solar Radiation Data Manual, averaged over 1961 to 1990.

• Phoenix flat panels average 8.4 peak sun hours in June and 3.0 in December, per NREL station 23183.
• Albuquerque flat panels average 8.1 peak sun hours in June and 2.9 in December, per NREL station 23050.
• Tampa flat panels average 6.1 peak sun hours in June and 3.1 in December, per NREL station 12842.
• Seattle flat panels average 5.8 peak sun hours in June and 0.8 in December, per NREL station 24233.
• Tilting Phoenix panels south at latitude angle, about 33 degrees, raises December from 3.0 to 4.9 peak sun hours, about 63% more, per the same station file.

Daily output of a 400-watt array, flat unless noted. Source: NREL Redbook 1961 to 1990 averages x 0.75 planning factor.

Location and month	Peak sun hours	400W makes about	Use case
Phoenix, June	8.4	2,520 Wh	Covers a 2,440 Wh remote worker’s day with about 80 Wh to spare
Phoenix, December	3.0	900 Wh	Weekend loads only
Phoenix, December, tilted at latitude	4.9	1,470 Wh	Portable panels aimed at the low sun
Tampa, December	3.1	930 Wh	Gulf Coast snowbirds
Seattle, December	0.8	240 Wh	Solar is a supplement, not a source

Wintering on Arizona public land? Our guide to long-term visitor areas covers where full-timers park for months at a time. For your exact spot and panel angle, model it in NREL’s free PVWatts calculator.

The same 400 watts of panels, two months apart. Built from NREL station averages.

Illustration: a flat roof panel beside a tilted portable panel. Tilt gains about 63% in a Phoenix December.

Three real setups, sized for summer and winter

These three profiles show how far one load moves between a June and a December array. Each fixes a math error from the earlier version of this page, where every array was smaller than its own load. The loads are examples for 12-volt rigs that cook on propane. Replace them with your monitor readings. All arrays use flat panels and the 0.75 planning factor from the section above.

Weekend Warrior: 830 Wh a day

Two people, two or three nights out. Loads: compressor fridge 490 Wh, water pump 40 Wh, LED lights at 10 watts for 8 hours (80 Wh), two phones 100 Wh, vent fan at 20 watts for 6 hours (120 Wh). No inverter running.

• Solar: 132 watts covers a Phoenix June day. A Phoenix December day needs 369 watts flat or 226 watts tilted.
• Battery: one day of storage is 830 Wh usable, about 81 Ah of lithium or 138 Ah of AGM at a 50% average discharge.

Full-Time Couple: 1,870 Wh a day

Two people living aboard. Loads: fridge 490 Wh, two laptops at 60 watts for 6 hours (720 Wh), lights 120 Wh, vent fan 160 Wh, water pump 40 Wh, phones and tablets 100 Wh, inverter idle 240 Wh.

• Solar: 297 watts covers a Phoenix June day. A Phoenix December day needs 831 watts flat or 509 watts tilted.
• Battery: two days of storage is 3,740 Wh usable, about 365 Ah of lithium at 12.8 volts.

Full-Time Remote Worker: 2,440 Wh a day

One person working online. Loads: fridge 490 Wh, laptop and monitor at 100 watts for 9 hours (900 Wh), internet terminal at 40 watts for 12 hours (480 Wh), lights 80 Wh, fan 160 Wh, pump 40 Wh, phone 50 Wh, inverter idle 240 Wh.

• Solar: 387 watts covers a Phoenix June day. A Phoenix December day needs 1,084 watts flat or 664 watts tilted.
• Battery: two days of storage is 4,880 Wh usable, about 477 Ah of lithium.

Internet gear is the remote worker’s swing load. Our Starlink vs 5G setup guide compares the options.

Solar needed by profile and season. Flat panels, NREL peak sun hours, 0.75 planning factor.

Profile	Daily load	Phoenix June	Phoenix December	Seattle December	Use case
Weekend Warrior	830 Wh	132 W	369 W	1,383 W	Short trips, battery carries most of the load
Full-Time Couple	1,870 Wh	297 W	831 W	3,117 W	Snowbirds, needs a second charge source in winter
Full-Time Remote Worker	2,440 Wh	387 W	1,084 W	4,067 W	Year-round off-grid work, plan alternator charging

A 3,117-watt array is far more panel than a van roof holds. In a Pacific Northwest winter, solar alone cannot carry a full-time couple. Driving, shore power or a generator fills that gap.

Our rig: a 2018 Hymer Aktiv

Our Hymer came with EcoTrek lithium power modules. We replaced them with two Epoch 300 Ah lithium batteries, for 600 Ah at 12.8 volts, or 7,680 Wh nominal. At an 80% planning margin that is about 6,140 Wh usable. The shop also added a 300-amp fuse between the batteries and the underhood alternator, a 70-amp fuse between the disconnect and the batteries and a 30-amp breaker to isolate the solar. We kept the original 2,000-watt inverter.

On basic loads (lights, the microwave, phone charging) we go several days between charges. Our rig has 250 watts of roof solar on its own 30-amp breaker. Flat on the roof, it makes about 1,575 Wh on a Phoenix June day and about 560 Wh in December. That is roughly 20 amps at best. Family RVing Magazine’s 2017 Aktiv review lists a 280-amp underhood alternator and a 2,000-watt inverter for the Aktiv. The alternator’s rating is more than ten times what our panels can deliver.

The Hymer’s control panel shows battery voltage and the inverter switch. Turn the inverter off when you are not using AC power.

Where you are so far: measure your daily watt-hours, size the array for December instead of June, and plan on driving or shore power to cover the gap. The next step is storage.

How much battery do you need?

Store at least one full day of use, and two days if you live aboard. The battery carries you through nights, clouds and the days you park in shade. The usable share differs by chemistry, so the same daily load needs a much bigger lead-acid bank than a lithium one. These rules cover 12-volt house banks. For lead-acid, Lifeline advises owners to “design your battery bank to maintain average depth of discharge below 50%” on its AGM battery page.

• Usable Wh needed = daily Wh x days of storage.
• Lithium iron phosphate (LiFePO4): we plan on 80% of rated capacity. Battle Born rates its 100 Ah battery for 100% depth of discharge on its data sheet. Its 3,000 to 5,000 cycle rating does not state the depth of discharge used.
• Renogy rates its Core Mini 100 Ah battery at 5,000 cycles at 80% depth of discharge, tested at 25°C, per its product page.
• AGM: plan on 50% for cycle life. Lifeline’s same page allows deeper discharges up to 80%, at a cost in battery life.

Worked example for the Full-Time Couple: 1,870 Wh x 2 days = 3,740 Wh usable. In lithium that is 3,740 / 0.8 = 4,675 Wh rated, or about 365 Ah at 12.8 volts. In AGM it is 7,480 Wh rated, or about 623 Ah at 12 volts. As of October 13, 2026, Battle Born lists its 100 Ah battery at $799 and Renogy lists the Core Mini 100 Ah at $307.99.

Component build, power station, or hybrid?

A component build fits permanent full-time use. A power station fits renters, weekenders and anyone who cannot cut into the rig. Both store the same energy. The difference is how they install, expand and run 12-volt loads. This comparison covers 12-volt rigs without battery-powered air conditioning. For a side-by-side of lithium banks, power stations and generators with prices, see our RV power options comparison.

The 10-amp socket limit matters because Dometic rates the CFX3 45 fridge at 8.2 amps of DC input on its spec sheet. A fridge, a fan and a water pump together can pass 10 amps. Some units add a higher-current Anderson port. The table lists list prices as of October 13, 2026. Sale prices and stock change weekly.

Power stations against the Full-Time Couple’s 1,870 Wh day. Days = rated Wh x 0.8 / 1,870. Specs from manufacturer pages, accessed October 13, 2026.

Unit	Rated Wh	Days, base unit	Max with expansion	Solar input	12V high-current port	List price	Use case
EcoFlow DELTA Pro 3	4,096	1.8	12 kWh	2,600 W, up to 150 V	Anderson 30 A	$3,299	Full-timers who want one large box
EcoFlow DELTA 3 Max Plus	2,048	0.9	10 kWh	1,000 W	Anderson 30 A, shared	$1,599	Start small, add batteries later
BLUETTI Apex 300	2,765	1.2	19,354 Wh	2,400 W, up to 60 V	Anderson 50 A with Hub D1	$1,699	Large storage, 50 A 12 V port with Hub D1
BLUETTI Elite 200 V2	2,074	0.9	Not expandable	1,000 W, up to 60 V	Car socket 10 A	$899	Weekend Warrior budget
Jackery HomePower 3000	3,072	1.3	Not expandable	1,000 W, up to 60 V	Car socket 10 A	$1,499	Fixed size, no expansion
Anker SOLIX F3800 Plus	3,840	1.6	26.9 kWh	3,200 W, up to 165 V	Car socket 10 A	$2,699.99	Big trailers that need room to expand
Anker SOLIX C2000 Gen 2	2,048	0.9	4 kWh	800 W, up to 60 V	Car socket 10 A	$1,499.99	Vans with an 800 W alternator charger. Backordered as of October 13, 2026

Choose a component build when

• You need more usable storage than one base unit holds. The largest we checked, the 4,096 Wh DELTA Pro 3, gives about 3,280 Wh at an 80% margin.
• Your 12-volt loads run past 10 amps at once.
• You want the alternator wired straight to the house bank, the way our Hymer is.

Common parts: LiFePO4 batteries (Battle Born, Renogy, Epoch), an MPPT charge controller such as the Victron SmartSolar 100/50, rated for 50 amps and 700 watts of panels at 12 volts, and an inverter sized to your largest AC load.

Choose a power station when

• You rent, lease or cannot drill the roof.
• Your loads fit under 10 amps of 12-volt output, or the unit has an Anderson port.
• You want to move the battery between the RV, the tow vehicle and the house.

Choose a hybrid when

• You already own a small factory bank and need more storage without rewiring.
• You want portable panels feeding a power station while roof panels charge the house bank.

Three ways to store solar in an RV. Each ends at the same 12-volt and 120-volt loads.

Illustration: a power station charging beside a Class B. Run 12-volt loads from its DC ports, not the inverter.

How do you charge when the sun quits?

Plan a second charging source, because a full-time couple needs about 831 flat watts in a Phoenix December and about 3,117 in Seattle. Solar covers the sunny days, and the alternator, shore power or a generator covers the rest. This matters most from November through February and north of the Sun Belt. Our Hymer’s 250 watts of roof solar make roughly 20 amps. Family RVing Magazine lists a 280-amp underhood alternator for the Aktiv.

• DC-to-DC alternator charger: charges the house bank from the vehicle at a set current. Victron rates the Orion XS 12/12-50A at 700 watts continuous up to 40°C.
• One hour of driving at 700 watts adds up to about 700 Wh. That is close to the 900 Wh that 400 flat watts make on a Phoenix December day.
• Power station alternator chargers: EcoFlow sells an 800W Alternator Charger. Anker sells an 800-watt Alternator Charger. BLUETTI sells the 560-watt Charger 1 and the Charger 2, rated for 800 watts of alternator input. Jackery sells a 600-watt DC-DC Alternator Charger. Check each brand’s compatibility list.
• Car socket charging: slow. A 10-amp, 12.6-volt socket delivers 126 watts, about 378 Wh in a three-hour drive.
• Shore power and generators: the fastest refill. Use them to reset the bank after a cloudy stretch.

Cold adds a second problem. Check your lithium battery’s low-temperature charging limit before winter. Our winter boondocking guide covers cold-weather battery care.

Wiring and safety basics

Lithium banks and solar arrays carry enough current to start a fire. Have a qualified RV technician inspect any permanent install, and follow each manufacturer’s wiring instructions.

Keep panel voltage under your controller’s limit on the coldest morning you will see. Cold raises panel voltage, and every controller lists a maximum input voltage. This applies to panels wired in series on any controller or power station. Victron’s MPPT manual warns, “At ambient temperatures below 25°C, the Voc will be higher,” in its installation guide. Voc is a panel’s open-circuit voltage.

• Series vs parallel: series adds voltage, parallel adds current. Series strings hit 60-volt power station limits fast.
• Input limits: the Victron SmartSolar 100/50 takes 100 volts. Victron’s 150/45 lists 150 volts as the absolute maximum in the coldest conditions, per its datasheet.
• Cable size: Victron’s Wiring Unlimited guide says, “You should aim for a voltage drop below 2.5%,” on its DC wiring page.
• Fuses and disconnects: fuse every positive cable near the battery, and add a breaker to isolate the solar, as our shop did.
• Codes: RV electrical work falls under NFPA 1192 and the National Electrical Code, NFPA 70.

Can solar run your RV air conditioner?

Check your air conditioner’s daily draw against your array’s daily output before counting on solar. A 400-watt array makes about 2,520 Wh on a Phoenix June day, and the AC competes with every other load for it. This applies to 120-volt rooftop units on inverter power. Read the running amps on the AC’s data plate, multiply by 120 volts and by hours of use. If that number beats your array’s output, run the AC on shore power or a generator.

RV solar power FAQ

How much solar do I need for full-time RV living?

Divide your daily watt-hours by your winter peak sun hours times 0.75. A full-time couple using 1,870 Wh a day needs about 831 watts of flat panels in a Phoenix December, or 509 watts tilted. In summer, 297 watts covers the same load. Pair any array with a second charge source.

Is 400W of solar enough for an RV?

It depends on the month. Using NREL averages and our 0.75 planning factor, 400 flat watts make about 2,520 Wh a day in a Phoenix June and about 900 Wh in December. That covers a weekend load year-round in the Southwest, but not a full-time couple in winter without alternator or shore charging.

How many batteries do I need to run an RV fridge?

Dometic rates its CFX3 45 compressor fridge at 490 Wh per 24 hours at its own test point. One 100 Ah lithium battery at 12.8 volts holds 1,280 Wh, or about 1,024 Wh at an 80% planning margin. That runs the fridge alone for about two days with no charging.

Can you run an RV on solar power alone?

In the Southwest from spring through fall, many small rigs can. In winter, flat panels in Seattle average 0.8 peak sun hours in December, per NREL data from 1961 to 1990. At that level a 400-watt array makes about 240 Wh a day, so full-timers should plan on alternator, shore or generator charging.

Are portable power stations good for full-time RV living?

They work when the daily load fits the unit’s storage and its 12-volt port. A 4,096 Wh EcoFlow DELTA Pro 3 covers about 1.8 days of a 1,870 Wh couple’s load at an 80% margin. Most car sockets on the units we checked cap at 10 amps, which limits several 12-volt loads at once.

How do I charge RV batteries while driving?

Install a DC-to-DC charger between the vehicle and house batteries, or use a power station brand’s alternator charger. Victron rates its Orion XS 12/12-50A at 700 watts continuous. A plain 10-amp car socket delivers about 126 watts. Have a technician check that your alternator can handle the added load.

How much does an RV solar system cost?

Storage drives the price. As of October 13, 2026, Battle Born lists a 100 Ah lithium battery at $799 and Renogy lists its Core Mini 100 Ah at $307.99. Power stations sized for full-time use list from $1,499 to $3,299. Panels, controller, wiring and installation add to any component build.

Your next step

Put a battery monitor on your bank and log one normal week. Divide the average day by your winter peak sun hours from NREL PVWatts times 0.75. That gives your array size. Then match storage and a second charging source using the tables above, and price the hardware in our lithium vs power station comparison. Budgeting a full year on the road? Our boondocking cost breakdown covers the rest. Browse more RV resources for water, dump stations and campsite finders.

Sources

1. Anker SOLIX. “F3800 Plus” and “C2000 Gen 2.” Accessed October 13, 2026. https://www.ankersolix.com/products/f3800-plus
2. Battle Born Batteries. “BB10012 Data Sheet.” Accessed October 13, 2026. https://battlebornbatteries.com/cdn/shop/files/BB10012_Data_Sheet.pdf
3. BLUETTI. “Apex 300.” Accessed October 13, 2026. https://www.bluettipower.com/products/apex-300-home-battery-backup
4. BLUETTI. “Elite 200 V2.” Accessed October 13, 2026. https://www.bluettipower.com/products/elite-200-v2-portable-power-station
5. Dometic. “CFX3 45 Electric Coolbox.” Accessed October 13, 2026. https://epi.dometic.com/en-gb/outdoor/coolers/electric-coolboxes/dometic-cfx3-45-223545
6. EcoFlow. “DELTA Pro 3 Portable Power Station.” Accessed October 13, 2026. https://us.ecoflow.com/products/delta-pro-3-portable-power-station
7. Family RVing Magazine. 2017 Hymer Aktiv review. https://magazine.frva.com/?p=7040
8. Jackery. “HomePower 3000.” Accessed October 13, 2026. https://www.jackery.com/products/jackery-homepower-3000
9. Lifeline Batteries. “Deep Cycle AGM.” Accessed October 13, 2026. https://lifelinebatteries.com/deep-cycle-agm/
10. National Fire Protection Association. “NFPA 70 (NEC)” and “NFPA 1192.” Accessed October 13, 2026. https://www.nfpa.org/codes-and-standards/nfpa-70-standard-development/70
11. National Renewable Energy Laboratory. “Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors,” stations 12842, 23050, 23183, 24233. 1961 to 1990 data. https://rredc.nrel.gov/solar/old_data/nsrdb/1961-1990/redbook/sum2/23183.txt
12. National Renewable Energy Laboratory. “PVWatts Calculator.” https://pvwatts.nrel.gov/
13. Renogy. “Core Mini 12.8V 100Ah Lithium Iron Phosphate Battery.” Accessed October 13, 2026. https://www.renogy.com/products/core-mini-12-8v-100ah-lithium-iron-phosphate-battery
14. U.S. Department of Energy. “Solar Radiation Basics.” Accessed October 13, 2026. https://www.energy.gov/cmei/systems/solar-radiation-basics
15. Victron Energy. MPPT 100/50 and 150/45 datasheets, Phoenix inverter datasheet, Orion XS technical data, Wiring Unlimited. Accessed October 13, 2026. https://www.victronenergy.com/media/pg/The_Wiring_Unlimited_book/en/dc-wiring.html

About the author: Chuck Price has RVed for more than 35 years and boondocks with his wife Cindy in a 2018 Hymer Aktiv. He is affiliated with the Family RVing Association. More about Chuck.

Product specs, prices and stock change often. Confirm current details with each manufacturer before you buy. Electrical work carries fire and shock risk. Have a qualified RV technician inspect any permanent solar or battery install.