Ranger tug power Management Calculator
How Much Power Does Your Boat Actually Use?
Free Power Management Calculator — Built from 6 Years of Real Data on a Ranger Tug in the Pacific Northwest
Owners are often surprised by how much power their boat actually consumes — and how quickly it adds up.
Now you can find out before you run out.
We built this spreadsheet for ourselves when we converted Channel Surfing to lithium and upgraded our solar. Six years of refinement, real Pacific Northwest solar production data, and actual wattage measurements from our own boat. We've been sharing it with owners ever since.
Enter your daily usage — how long you'll watch TV, run the microwave, run the heater, use the radio, cabin lights, charge devices, run the engine — and it calculates exactly what state of charge your battery bank will be at the end of the day.
This works for any Fluid Motion boat.
Non-Fluid Motion owners can adapt it without much trouble.
What's inside:
- Ranger Tug R27 — NW Edition (AGM and LFP retrofit) and LE Edition (factory LFP)
- Ranger Tug R29 and R31 — Factory AGM and Factory LFP
- Solar upgrade sizing with real Pacific Northwest production data by season — January fog, September rain, summer peak in June/July/August.
- AGM vs LFP battery capacity comparison
- Real wattage data for every major onboard system
- Instant state of charge calculation based on your actual usage
This is not a manufacturer estimate. This is six years of real data from a boat that has cruised 12,949 miles including a 2,600-mile round trip to Glacier Bay, Alaska. Updated for 2026.
Ranger Tug Power Management Calculator
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