Electrical wire size?
a.) Choose a wire to carry a maxium of 5A from a solar panel to the batteries 25ft away.
What would the wire resistance and voltage drop be in question a.) ..?
depends on how much voltage drop you want to allow. For a solar panel, that is probably well less than 1 volt, as any drop is totally wasted. Say 0.5 volts? That means a resistance of less than 0.5v/5 amps = 0.1Ω.
for 50 ft, look resistance up in wire tables.
#14 is 2.5Ω/1000 ft, so that is 0.25Ω per 100 ft or 0.12Ω per 50 ft.
You can use that, or go with #12, which is 1.6Ω/1000 ft or 0.08Ω for 50 ft. with #12, you will lose I²R = 25*0.08 = 2 watts.
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