Wire Loss Table for 12 and 24 Volt Systems
Wire Loss Tables for Wind Turbines & Solar Panels
Use the wire loss tables below to determine the maximum distance one-way in feet of various gauges of two-conductor copper wire from the power source to load for 2% voltage drop in 12-volt and 24-volt system wiring. You can go twice the distance where a 4% loss is acceptable. Do not exceed the 2% drop for wire between PV modules (solar panels) and batteries. A 4% to 5% loss is acceptable between batteries and lighting circuits in most cases.
Note that if you change an array from 12 volts to 24 volts and the wattage remains the same, then the current is cut in half. This allows you to go 4 times as far with the same wire gauge with the 24-volt array as you could with the 12-volt array.
Wire Loss Table - 12 Volt Systems
Wire Size |
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Amps |
#14 |
#12 |
#10 |
#8 |
#6 |
#4 |
#2 |
1/0 |
2/0 |
4/0 |
12 Volt System - 2% Voltage Drop |
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1 | 45 | 70 | 115 | 180 | 290 | 456 | 720 | |||
2 | 22.5 | 35 | 57.5 | 90 | 145 | 228 | 360 | 580 | 720 | 1060 |
4 | 10 | 17.5 | 27.5 | 45 | 72.5 | 114 | 180 | 290 | 360 | 580 |
6 | 7.5 | 12 | 17.5 | 30 | 47.5 | 75 | 120 | 193 | 243 | 380 |
8 | 5.5 | 8.5 | 15 | 22.5 | 35.5 | 57 | 90 | 145 | 180 | 290 |
10 | 4.5 | 7 | 12 | 18 | 28.5 | 45.5 | 72.5 | 115 | 145 | 230 |
15 | 3 | 4.5 | 7 | 12 | 19 | 30 | 48 | 76.5 | 96 | 150 |
20 | 2 | 3.5 | 5.5 | 9 | 14.5 | 22.5 | 36 | 57.5 | 72.5 | 116 |
25 | 1.8 | 2.8 | 4.5 | 7 | 11.5 | 18 | 4829 | 46 | 58 | 92 |
30 | 1.5 | 2.4 | 3.5 | 6 | 9.5 | 15 | 24 | 38.5 | 48.5 | 77 |
40 | 2.8 | 4.5 | 7 | 11.5 | 18 | 29 | 36 | 56 | ||
50 | 2.3 | 3.6 | 5.5 | 9 | 14.5 | 23 | 29 | 46 | ||
100 | 2.9 | 4.6 | 7.2 | 11.5 | 14.5 | 23 | ||||
150 | 4.8 | 7.7 | 9.7 | 15 | ||||||
200 | 3.6 | 5.8 | 7.3 | 11 |
Wire Loss Table - 24 Volt Systems
Wire Size |
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Amps | #14 | #12 | #10 | #8 | #6 | #4 | #2 | 1/0 | 2/0 | 4/0 |
24 Volt System - 2% Voltage Drop |
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1 | 90 | 140 | 230 | 360 | 580 | 912 | 1440 | |||
2 | 45 | 70 | 115 | 180 | 290 | 456 | 720 | 1160 | 1440 | 2120 |
4 | 20 | 35 | 55 | 90 | 145 | 228 | 360 | 580 | 720 | 1160 |
6 | 15 | 24 | 35 | 60 | 95 | 150 | 240 | 386 | 486 | 760 |
8 | 11 | 17 | 30 | 45 | 71 | 114 | 180 | 290 | 360 | 580 |
10 | 9 | 14 | 24 | 36 | 57 | 91 | 145 | 230 | 290 | 460 |
15 | 6 | 9 | 14 | 24 | 38 | 60 | 96 | 153 | 192 | 300 |
20 | 4 | 7 | 11 | 18 | 29 | 45 | 72 | 115 | 145 | 232 |
25 | 3.6 | 5.6 | 9 | 14 | 23 | 36 | 58 | 92 | 116 | 184 |
30 | 3 | 4.8 | 7 | 12 | 19 | 30 | 48 | 77 | 97 | 154 |
40 | 5.6 | 9 | 14 | 23 | 36 | 58 | 72 | 112 | ||
50 | 4.6 | 7.2 | 11 | 18 | 29 | 46 | 58 | 92 | ||
100 | 5.8 | 9.2 | 14.4 | 23 | 29 | 46 | ||||
150 | 9.6 | 15.4 | 19.4 | 30 | ||||||
200 | 7.2 | 11.6 | 14.6 | 22 |