Calling on Solar Techies
I have been thinking of going solar for some time and decided to pull the plug. My wants are a 400 to 500 watt system. I have four 12 volt batteries with 340ah. I am not planning on changing b...
Forum Discussion
1L243 wrote:
Thanks for all the great information. I will install the system as it is now except for going to 8ga wire from the panel junction to the Charge Controller at the batteries. According to the low voltage calculator this helps to lower voltage drop over 30 feet to 5.76%. Speaking of the low voltage calculator. I put in the parameters of the 500 watt kit as it came from the manufacture and it still came in at 4.5% voltage drop which is above the 3% recommended goal. Makes me wonder about the accuracy of the calculator. The kit comes with a 15 foot run to the Charger Controller and 10ga wire.
As far as MPPT vs PWM the PWM came with the kit and just did not want to throw it away. The difference in price between the was only $100. In the future I will probably go MPPT just because you seem to have more options.
Thanks again
There is no issue with a greater than 3% voltage drop in the wiring between the panels and controller. In fact as long as the voltage drop is less than the difference between the panel maximum power voltage (~18V) and the battery voltage (~14.7V), or about 25%, then nothing is lost as the PWM charger doesn't use this voltage anyway.
