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.
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).
Frequently Asked Questions
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.
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, Developer & Off-Grid Energy Enthusiast. On the energy side, Dan has hands-on experience with residential solar panel installation, DIY battery bank construction, off-grid power systems, and wind power — all from building and maintaining his own systems..
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.