Instead of guessing, let's look at what's needed.
The panel under discussion is 195W, Imp = 5.38A, Vmp = 36.2V. Three panels in parallel will bring cable current to 16.1A. We'll design the cable for a 1% voltage drop. Assume cable length of 30 ft (round trip).
Total cable resistance is:
R_cable = 36.2V * .01 / 16.1A = 22 mohm
Cable resistance per foot is:
R_cable per foot = 22 mohm / 30 ft = 0.75 mohm/ft
8 awg cable (0.63 mohm/ft) looks like a good fit. It costs about a quarter per foot. 30 ft costs a whopping $7.50.
Are you serious the $7.50 cost is a factor to get an efficient design? Do you really think 8 awg cable is difficult to work with?
I don't know Almost, you got some fuzzy logic. The OP wants to buy the cheapest panels on earth, yet you want him to purchase a $60 combiner box??? When a substitute box can be gotten for under $5?
Almot wrote:
Salvo wrote:
One of the myths around here is that series is better than parallel because you can use smaller cable. Going to higher voltage Vmp comes at a cost. In this case, efficiency drops by 5%. Charging current will forever be 5% lower.
The OP can use the same hardware and connect panels in parallel. The panel cable will be a little larger, but so what?
It's not a myth :).
24V in series do use a smaller cable - much smaller, like #10 vs #4. Cable cost - higher with parallel - is only one of variables.
