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.
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 <a href="/solar/how-many-batteries-for-camper">camper battery sizing calculator</a> matches solar panels to your battery bank specifically for RV use.
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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.
Last updated:
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.