Battery and CCTV system for my van

[DainiusG]

Hi,
So I decided to build a little CCTV system for my van. It would be front, rear and both side under mirror cameras. Much like or close to a 360 or a BirdsEyeView system (sans the 3d capabilities). Due to a long (about 60 second) system boot-up time I want to make it a little smarter using a micro-controller. I have drawn up a crude plan of the layout. But I need a second opinion on how to proceed.
1. For example what should I use for switching the devices like (main battery, cameras, monitor, ...) on and off (relays, transistors,...???).
2. What would be the best battery for this kind of application( my dvr and cameras draw about 1amp@12-14V) Idealy I would like to get atleast 24Hrs of recordings before powering down to standby.
3. What would be the do`s and dont`s when working with something like this?
here is the drawing
http://www.gliffy.com/go/publish/8909633

Thanks for reading and any input. ;]

 

[SawMaster]

Transistor switching is more reliable, faster, and takes a lot less current than a relay does. But the last DVR switch might be cheaper as a relay; 3A is a fairly heavy spike, and spikes don't do nice things in many electronic circuits. But neither do short-term arcs across relay contacts, so you might need to connect to a grounded capacitor on the 'switched' side of the contacts to make everything play together well.

I think the biggest problem you'll encounter is with the outside cams. They need to be waterproof, but you'll have condensation issues unless they can 'breathe', especially as you go in and out of sun and rain conditions. Not easy to have both together.

When I get around to it, I'm going to try aiming a cam into my van's spot mirror from the inside. I don't know how that will work but at least there won't be condensation or waterproofing to worry about. Mine is a big round spot, and with eyesight it has great coverage so once I get the focus correct I think a cam will work fairly well like that. By the time it's coverage is passed there will be little space to the front cam coverage area, and a passing car will not ever be completely out of one picture or the other.

Phil