We all want to get the most out of our solar systems, and that includes the set up of batteries and panels. The maximum distance between solar panels and batteries should be 20 to 30 ft. The shorter the distance between them the better. Long, thin cables increase the amount of energy lost as the conductor resists current flow.
The distance between your solar panel and battery will affect how efficiently your system works. Longer wiring distances can cause voltage drop, which reduces the amount of power that reaches your batteries. The further the distance, the greater the voltage drop and loss of power.
To minimize voltage drop, it is recommended to keep the distance within 30 feet (9 meters) between the solar panels and the inverter. However, a distance of 100 feet can still result in an acceptable voltage drop of 3% or less. Thicker cables can help mitigate the issues of resistance and voltage drop.
The array should be within 30 feet of the batteries, and the controller should be within a yard of the batteries. The controller is not closer to the solar panels than it is to the batteries because it will limit the power provided by the solar panels, and there will be some bleed-off that occurs naturally.
The best answer is shorter is better in terms of distance. Solar Battery storage systems should be within 20-30 feet, and you would mount the charge controller within a yard or meter of the batteries. Compact solar design is an essential part of preventing energy loss.
Suppose you are designing a solar array and wonder how far apart the solar components — the panels, controller, inverter, and home — should be from each other. In that case, the simple answer is as close together as possible. The array should be within 30 feet of the batteries, and the controller should be within a yard of the batteries.