Daily energy budget

RV power consumption calculator

Total a representative day of refrigeration, electronics, lighting, pumps, and other DC or inverter-powered equipment.

Enter watts and daily run time

Use equipment labels or manufacturer specifications. Convert amperage to watts with watts = volts × amps.

Battery system
Daily loads
Load groupWattsHours/dayDuty cycleRefrigeration
%
Electronics & instruments
%
Lighting
%
Pumps
%
Other / inverter loads
%

Hours/day is the time the equipment could be active; duty cycle is the percentage of that window it actually draws the entered watts. Use 100% for continuous loads. Enter appliance watts before losses; apply efficiency in the battery and solar steps. Include inverter idle draw as a load if known.

Additional named appliances

Use these four rows for separate schedules. Set a group's watts above to zero if these rows replace it, so an appliance is not counted twice. Watts are per item; leave unused rows at zero watts.

Appliance 1
Appliance 2
Appliance 3
Appliance 4

Trip energy assumes the same daily schedule. This does not change daily energy passed to battery or solar sizing.

Formula

Convert daily watt-hours to amp-hours

Wh/day = watts per item × quantity × hours × duty cycle % ÷ 100
Ah/day = Wh/day ÷ system volts

A clamp meter, battery monitor, or shunt can replace assumptions with measured consumption.

Next step

Turn the load budget into a system

Send the daily watt-hours to the battery and solar calculators. Account separately for short-duration surge loads and equipment that cannot be allowed to shut down.

Battery bank calculatorSize amp-hours →RV solar calculatorReplace daily energy →Charging-time calculatorEstimate recovery →

Return to the solar, battery & RV planning workflow

A daily appliance worksheet: worked example

A 45 W refrigerator available for 24 hours with a 35% duty cycle uses 378 Wh. Add 240 Wh electronics, 100 Wh lighting, 60 Wh pumps, and 200 Wh other loads: 978 Wh/day, or 0.978 kWh/day. At 12 V this is 81.5 Ah/day before losses.

Frequently asked questions

Should I enter 24 hours and a duty cycle?

Yes, if the appliance is available all day but cycles on and off. If you already measured its actual running hours, enter those hours and 100% duty cycle to avoid counting cycling twice.

Where do inverter losses go?

Enter appliance-side energy here. Battery sizing applies delivery efficiency, and solar sizing applies overall panel-to-load efficiency to this same budget. If your measurements already include those losses, set the corresponding downstream efficiency to 100%.

How do I enter more than one appliance in a group?

Use quantity for identical appliances with the same schedule. Use a named appliance row for a different schedule, and remove its watts from the group total above to avoid double counting. Connected watts does not include startup surge.