How to connect solar panels to batteries?

I have two solar panels that were going to be trashed at work. I want to use them to charge batteries on my RV but i noticed they put out around 20 volts in direct sunlight. So i am wondering:
-isn’t this way too much voltage for a 12 volt system?
-do a need some sort of a regulator connected to keep them from overcharging?

How much does it cost to install solar panels?

I already have 18 solar panels I just want to know how much it will cost to install them.
Please give me a price i don’t want to call someone and ask them to give me a quote, i want an actual price.
I just want them hooked up to my house so i wouldn’t have to use the city’s power, and no i do not have any batteries.

Who thinks that we should power traffic lights with solar panels?

The solar panel wouldn’t need to be very large, and for the most part could be on the back or top of the street light. At night, they could be powered the same way they are now or by batteries that the solar panels could be charging throughout the day. Please explain to me if you think this is good or bad.

How long can the solar power systems remain switched off?

I have recently installed solar power systems in my home. I need to go away for two months during which the house will remain closed. What do I do with the systems,leave it on or switch everything off for that period? Will this affect the charger,batteries or the inverter?

How many solar panels does it take to run an A/C unit? Also, How many batteries in an array?

I was wondering how many 700 W solar panels it would take to run a household A/C unit. Also curious how many batteries it would take to keep A/C running in inhospitable environments. Would a 3500 W inverter be enough if it were to run 220 AC?

I want to power my new home I am building on solar power alone what will the cost be roughly?

I also want to stay off the electric grid . It would cost an additional ten thousand dollars to be hooked into it and I want to be independant from utilities. Would solar panels and batteries power lights and T.V , computer , washer dryer ect.