Minimum Battery Wire Sizing - 75ºC rated copper

  • Published on Mar 12, 2026
  • 1 minute(s) read
Prev Next

MODEL

Wire Size in a raceway, cable, or earth1

Wire Size in free air2

Metric Wire Size3 (mm2)

@30°C

30°-45°C

@30°C

30°-45°C

GS-MPPT-60

#4 AWG

3 AWG > 40°C

#6 AWG

#6 AWG

16 - 25

GS-MPPT-80

#3 AWG

2 AWG > 30°C

1 AWG > 40°C

4 AWG

#.4 AWG

25 - 35

GS-MPPT-100

#1 AWG

1/0 > 30°C

2/0 > 40°C

#4 AWG

3 AWG > 30°C

2 AWG > 40°C

35 - 50

1 Per NEC 2021 [see NEC Table 310.15(b)(16)], ampacity for not more than three current-carrying conductors in a raceway, cable, or earth (buried)

2 Per NEC 2021 [see NEC Table 310.15(b)(17)], ampacity for conductors in free air

3 Estimated. See local code requirements for metric cable sizing

Table A-2. Minimum DC battery wire sizes for 75ºC copper.