Log Your Daily 12V Appliance Amp-Hour Consumption & Battery Drain
Why You Need a Manual Power Audit
While calculators give you quick estimates, managing an off-grid electrical system successfully in an RV, camper van, or remote cabin requires knowing exactly how much energy your 12V appliances draw in the real world. Use this interactive worksheet to log your daily power usage across your Starlink Mini, diesel heater, compressor fridge, LED lights, and device chargers.
Enter your typical daily run times and operating wattage for each appliance to calculate your total Amp-Hours (Ah) and Watt-Hours (Wh) consumed on a 12V system.
Appliance
Avg Watts (W)
Hours / Day
Daily Watt-Hours (Wh)
Starlink Mini
224 Wh
12V Compressor Fridge
400 Wh
Diesel Parking Heater
240 Wh
LED Lighting & Water Pump
45 Wh
Laptop & Phone Charging (USB-C)
180 Wh
Your Total Daily Consumption:
1. Total Daily Energy Drain
0 Wh/day
0 Ah / day (at 12V DC)
Combined energy consumed across all active 12V appliances every 24 hours.
2. Recommended LiFePO4 Battery Bank (85% Depth of Discharge Limit)
0 Ah
Minimum 12V lithium battery capacity needed to sustain this daily draw with a safe reserve buffer.
💡 Pro Tip: Want to run your Starlink and appliances without draining your starter battery? Check out our Complete Starlink Mini 12V DC Installation Guide for standalone auxiliary fuse panel setups.
How to Conduct a Manual Power Audit in Your Rig
If you want to verify your exact power consumption before investing in expensive lithium batteries or solar arrays, follow this four-step field audit procedure:
List Every Load: Write down every single 12V, 24V, and 120V appliance you plug in during a normal day, noting whether it runs continuously or intermittently.
Measure Actual Wattage: Use a DC battery monitor (like a Victron SmartShunt) or a plug-in wattmeter to record real-time draw rather than relying solely on manufacturer label specs.
Track Operating Hours: Monitor how many hours per day each device actively operates. Remember that compressor refrigerators cycle on and off roughly 30% to 50% of the day depending on ambient temperature.
Convert to Amp-Hours: Divide your total daily Watt-hours by your system voltage (e.g., 12V) to find your total daily Amp-hour extraction, ensuring your solar panels can replace that exact amount during peak daylight hours.