Hello guys. I'm thinking this is going to be a dumb question for educated electronic people.
I live in a 12 volt house.
I wired it myself.
Panels through PV controller to batteries. Batteries to house fusebox. Fusebox to lights, stereo etcetera.
I want to add extra panels to the system. They will only fit on the roof of my house. Not on my battery shed.
Can I wire these panels, through a PV controller, into the 12v wires that enter the house. This would mean as I understand it. I will be requesting amps to flow to my house on request from appliances. And at the same time, sending charge back to the batteries along the same wiring. Can I do this.???

 

In Theory yes. In practice, probably not.

The resistance of the wiring between the house and the battery shed will make it such that the panels/controller on the house will not contribute to charging the batteries (very much).

How many amps is your max house load? What is the total wire length from the battery shed to the house fusebox? From the fuse box to the far side of house? What wire gauge are you using between these points?

Mounting the controller that serves the roof-top panels as close to the house fusebox will help slightly...

 

Hello Mike.
The wire from my shed to the house is 10 meters long. 20 Mil. Way way in excess of my total amp requirements.
My maximum amp draw is my Engel upright. It is another 20 meters of 10 Mil twin core away from fuse box. I was told this gauge was also in excess of requirements. The Engel draws a maximum of 2.5 amp hrs. The house panels will be mounted approx 3 meters of cable away from the 20 Mil that enters the house. I run small led (lights) and a water pump now and again.

 

I am confused about your units. In our system a 20mil wire is tiny. Is that 20mm?

What is an Engel? How many amps?

Could you post a sketch showing the relative placement of panels, batteries, loads, wire lengths and gauges, amp draw of loads.

 

Sorry, yes it's 20 mm (2 cm).
I have been trying to understand circuits and flows.
Would I be correct in assuming that the panels (in the sun) will supply some power to the house / fridge demands with possibly any excess amps required sent from the batteries.
Thanks for giving me your time.

 

Could you post a sketch showing the relative placement of panels, batteries, loads, wire lengths and gauges, amp draw of loads.

 

Yes. Your appliances will take what they need and any excess will go to the batteries. If a cloud goes overhead and you don’t have enough power for the appliances, they will draw some from the batteries.

 

Mike. I'm sorry. I am not very good at this type of communication. I don't know how to send you a picture.
And thanks DNA. If my house panels save my battery bank from drawing down, then that is a bonus.
Thanks.