We will try to use 12V with an car battery, I have to buy the charger / battery, what to buy. I have 1 112 board and a rb532 with 4 Wireless (Atheros AR5213) 3unit 400mw 1 65mw.
then we have 5 ovislink 5460 for our b/g user (switc to rb532 board) if it works. and the cabel from the battery is 45 meters. how big battery do we have to use 
wrong place
For this kind of use get a Deep Cycle Marine Battery - Over here in my country the best price/AH is a 225AH battery thats been running a RB532 and CM9 under full load for 10 days so far - will likly reach 20 days before voltage dips below 11v.
You will also want to buy a 12v Output reg to make sure you dont send and spiked or sags into the RB directly.
Dont use car battries because they are not meant for long term drain. they are designed to be pushed really hard when yoru car starts and then trickle charged by the alt - the only time the battery is in use is when the Alt is not powering enough or the car is starting
how much does it cost the Marine battery ?
About $200USD over here - You can pick them up from any good boat shop