Tacklebox ’n Tools
Test version

Power Station & Solar Sizer Calculator

List what you're bringing to camp and get the power station size, inverter output and solar panel that keep it all running for the whole trip.

How to use it

  1. Set your trip. How many days you'll be out.
  2. List your gear. An example camp is loaded. Change the watts and hours, remove what you don't bring, and add the rest. Mark gear that plugs into a wall outlet as AC.
  3. Add solar if you have it. Enter your panel's watts and pick the kind of sun you expect.
  4. Read the results. The power station size, inverter output and solar panel your trip needs, and how many days your setup lasts.

Your trip

days
Count each day and night you need power without plugging in.

Your gear

Watts are typical figures from published charts. The label on your own gear beats any estimate. AC means it plugs into the power station's wall outlet.

Your power station and solar

Wh
The watt-hour (Wh) number on the station. Not bought one yet? Leave it and see what the results recommend.
watts
Enter 0 for no solar.
A sun hour is one hour of full, direct sun. A long day of weaker sun adds up to fewer of them.

How the numbers are worked out

Daily use

Each item uses watts × hours × quantity watt-hours a day. A power station loses some energy to heat and to its inverter, so daily use is divided by 0.85, the same factor Jackery uses in its runtime formula (capacity × 0.85 ÷ watts).

Starting watts come from manufacturer figures where we could find them, listed under Sources. Items marked "estimate" are typical values. Swap in the number from your own gear.

Solar

Daily solar is panel watts × sun hours × 0.75. The 0.75 covers standard system losses (NREL's PVWatts model uses 14%) plus heat and imperfect aim on portable panels. It is our planning assumption, not a measured figure.

Sun-hour choices are rounded from NREL solar maps: sunny regions see about 6 full-sun hours, and much of the country gets 4 or fewer in December.

Station size

The station has to hold at least one full day of use. If solar falls short, it also has to cover the shortfall for every day of the trip. The recommendation is the larger of those two, rounded up to a common size.

AC output is everything marked AC running at the same time. Gear with a motor or compressor can pull several times its running watts for a moment at start-up, so leave headroom for those.

What it leaves out

  • Cold weather, which cuts battery capacity and slows charging
  • Charging from your vehicle while you drive
  • The small amount a station uses just being switched on

Planning estimates. Check that your power station's solar input accepts your panel's voltage and watts before connecting it. Medical devices such as CPAP machines deserve a backup plan.

Sources