Table 1 below gives some examples of battery cable cross sections calculated with formula
(5).
(in this case I and V in formula (5) are the output current and output voltage of the charge
controller)
Maximum
Maximum
Charge
solar array
current
output
@13,4V
500W
37A
750W
55A
1200W
85A 1)
Maximum
Maximum
Charge
solar array
current
output
@26,8V
500W
18A
1000W
37A
2400W
85A 1)
Maximum
Maximum
Charge
solar array
current
output
@40,2V
750W
21
1500W
42
3600W
85A 1)
Maximum
Maximum
Charge
solar array
current
output
@53,6V
1000W
21
2000W
42
4850W
85A 1)
1)
Taking into account 6% loss (battery cables + controller + PV cables + fuses)
Note 1: highlighted cable cross sections: minimum cross section due to thermal limit.
Note 2: please consult local regulations regarding maximum allowed current carrying capacity of cables.
Table 1: Battery cable cross section and power loss
6
12V system (solar array up to 1200W)
Battery
Power loss
Fuse
in battery
Rating
cablesα (%)
63A
1
80A
1,5
120A
2
24V system (solar array up to 2400W)
Battery
Power loss
Fuse
in battery
Rating
cables α (%)
35A
1
63A
1,5
120A
2
36V system (solar array up to 3600W)
Battery
Power loss
Fuse
in battery
Rating
cables α (%)
35
0,5
63
0,5
120
1
48V system (solar array up to 4850W)
Battery
Power loss
Fuse
in battery
rating
cables α (%)
35
0,5
63
0,5
120
1
Length 2x1,5 m
Length 2x2,5 m
2
2
mm
AWG
mm
16
5
25
16
5
25
25
3
35
Length 2x1,5 m
Length 2x2,5 m
2
2
mm
AWG
mm
6
10
10
10
7
10
25
3
25
Length 2x2,5 m
Length 2x5 m
2
2
mm
AWG
mm
6
10
10
10
5
25
25
3
25
Length 2x2,5 m
Length 2x5 m
2
2
mm
AWG
mm
6
10
10
10
7
16
25
3
25
Length 2x5 m
2
AWG
mm
AWG
3
Not recommended
3
Not recommended
2
Not recommended
Length 2x5 m
2
AWG
mm
AWG
7
16
5
7
25
3
3
25
3
Length 2x10 m
2
AWG
mm
AWG
7
16
5
3
35
2
3
35
2
Length 2x10 m
2
AWG
mm
AWG
7
16
5
5
35
2
3
35
2