How much battery capacity do I need for boondocking?

For a comfortable setup with a 12V fridge, lights, fan, phone charging, and occasional TV, plan for 1,200-1,500Wh per day. At 12V with 80% DoD, that means 125-155Ah of LiFePO4 per day without solar. For two days of autonomy (no sun at all), double it to 250-310Ah. Most serious boondockers settle on 200-400Ah of LiFePO4 at 12V paired with 200-400W of solar panels. Our off-grid load calculator helps you tally every appliance into a precise daily Wh budget.

Should I upgrade my RV batteries from lead-acid to LiFePO4?

If you boondock regularly, the upgrade almost always pays for itself. A typical RV has two Group 24 lead-acid batteries (about 150Ah total at 12V, 75Ah usable at 50% DoD). One 200Ah LiFePO4 battery (160Ah usable at 80% DoD) replaces both with more than double the usable capacity at half the weight. The LiFePO4 battery will outlast 4-5 sets of lead-acid batteries, making the lifetime cost similar or lower. It also charges faster — see the difference with our battery charge time calculator .

Can I run my RV air conditioner on battery power?

Technically yes, but the energy numbers are brutal. A small RV air conditioner draws 1,200-1,500W. Running it for 4 hours costs 4,800-6,000Wh — that is a 500Ah LiFePO4 bank at 12V nearly depleted in a single afternoon. Most off-grid RVers skip AC entirely and use fans, shade, and ventilation instead. If you must have battery-powered AC, look at 48V systems with 400+Ah banks and 1,000W+ of solar — serious hardware for serious comfort.

RV Battery Runtime Calculator — LiFePO4 House Loads

4 min read

RV battery runtime is the difference between a relaxing weekend off-grid and a frustrating scramble for a hookup site. This calculator helps you figure out whether your battery bank can handle your camping style — before you discover the answer the hard way in a remote campsite with no cell signal. Our RV battery sizing guide covers multi-day boondocking strategies and solar integration.

Recreational vehicle with battery compartment, window bay, and dual-axle wheels.

RV Appliance Power Draw Reference

RV Appliance	Watts	Typical Daily Use	Daily Wh
LED interior lights	5-20W	5 hours	25-100
12V fridge (compressor)	40-60W avg	24 hours	960-1,440
Water pump	40-100W	15 min	10-25
Vent fan (Maxxair/Fantastic)	5-40W	8 hours	40-320
Phone/tablet charging	10-20W	3 hours	30-60
TV (12V, 24")	30-50W	3 hours	90-150
Laptop charging	45-65W	2 hours	90-130
Coffee maker (inverter)	600-1,200W	10 min	100-200
Microwave (inverter)	800-1,500W	10 min	130-250
Electric blanket	50-100W	8 hours	400-800

The biggest surprise for most RVers is the fridge. A 12V compressor fridge running 24 hours uses 960-1,440Wh per day — more than everything else combined in a moderate-use scenario.

RV 12V electrical system diagram showing battery bank, fuse panel, inverter, and loads. — A typical RV system routes 12V DC through a fuse panel for lights and fridge, while the inverter supplies 120V AC outlets from the same battery bank.

Example: Weekend Boondocking

You are boondocking for two nights with a 200Ah 12V LiFePO4 battery bank and 200W of rooftop solar. Here is a realistic daily energy budget:

Fridge: 1,100Wh. Lights: 60Wh. Fan: 120Wh. Phone charging: 40Wh. Water pump: 15Wh. TV for 2 hours: 80Wh. Total daily draw: ~1,415Wh.

Battery bank capacity: 200Ah x 12V x 80% DoD = 1,920Wh usable. That covers one full day with 505Wh left over — but not two days without recharging.

Solar recovery: 200W of panels produce roughly 800-1,000Wh on a clear day with 4-5 peak sun hours. After one night of use, the battery is down to about 505Wh remaining. One day of solar adds 800-1,000Wh, bringing the bank back to 1,305-1,505Wh — enough to cover night two.

On a cloudy day, solar output might drop to 300-400Wh. That leaves you short. Bring a small generator as backup, or reduce loads (skip the TV, pre-cool the fridge before leaving home).

Worked Examples

Weekend Boondocking Power Budget

Context

You have a 200Ah LiFePO4 bank and plan two nights off-grid. Your loads: 12V fridge (20W avg), LED lights (15W for 5hrs), phone charging (10W for 2hrs), and a water pump (60W for 0.5hrs/day).

Calculation

Daily energy: (20x24) + (15x5) + (10x2) + (60x0.5) = 480 + 75 + 20 + 30 = 605 Wh/day

Two days: 1,210 Wh

Battery usable: 200 x 12 x 0.80 x 0.95 = 1,824 Wh

Days of autonomy: 1,824 / 605 = 3.0 days

Interpretation

Three days of autonomy from a single 200Ah battery. Your two-night trip fits comfortably with reserve to spare. Add a laptop or TV and runtime drops to under two days.

Takeaway

For longer boondocking stretches, add solar. Size the panel array with our solar panel and battery sizing calculator to match your daily energy use.

Can a 400Ah Bank Run RV Air Conditioning?

Context

Your rooftop AC draws 1,500W. You have a 400Ah 12V LiFePO4 bank with a 2,000W inverter. You want to know how long the AC runs on battery alone.

Calculation

Usable: 400 x 12 x 0.80 x 0.88 = 3,379 Wh

Runtime: 3,379 / 1,500 = 2.25 hours

Interpretation

Just over 2 hours. AC is the single biggest load in an RV and batteries alone cannot sustain it. You need either shore power, a generator, or an extremely large solar array.

Takeaway

Running AC off-grid requires serious solar investment. Estimate the panel count needed with our solar panel output calculator — expect 2,000W+ of panels for meaningful AC runtime.

Frequently Asked Questions

Glossary

Boondocking

Camping in an RV without hookups — no shore power, water, or sewer connections. All electrical needs must come from batteries, solar, or a generator. Also called dry camping or off-grid camping.

House Bank

The battery bank in an RV dedicated to powering living area loads (lights, fridge, outlets). This is separate from the chassis battery that starts the engine. House banks range from 100Ah in small vans to 800Ah+ in large motorhomes.

Daily Energy Budget

The total watt-hours consumed per day by all RV appliances. Calculated by multiplying each device's wattage by its hours of use. This number drives battery and solar sizing decisions.

Planning your solar setup? The camper battery sizing calculator matches solar panels to your battery bank specifically for RV use.

RV battery sizing comes down to one question: what loads are you willing to give up? Size your bank for the loads you refuse to cut, add solar for daily recovery, and keep a generator for cloudy stretches. Run the numbers above with your actual loads — not wishful thinking — and your boondocking trips will be comfortable instead of stressful.

More Battery calculators

Browse all battery calculators — LiFePO4, lead-acid, AGM, and lithium-ion runtime, charge time, and capacity sizing.

Last updated: March 17, 2026

Written and maintained by Dan Dadovic, Commercial Director at Ezoic Inc. & PhD Candidate in Information Sciences. He works professionally as Commercial Director at Ezoic Inc., leading revenue strategy across digital publishing.

Disclaimer: Calculator results are estimates based on theoretical formulas. Actual performance varies with temperature, battery age, load patterns, and equipment condition. For critical electrical work, consult a licensed electrician.

Editorial review by Doc. dr. sc. Damir Topić, Assistant Professor, FERIT Osijek.