Make sure you buy one with enough watts. Add up the watts for each device you want to run.
If a device rating is amps you can use OHM's law to calculate watts.
Example. 10 amp refrigerator. 120 volt x 10 amps = 1200 watts
To find the Power (P)
[ P = V x I ] P (watts) = V (volts) x I (amps)
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