Additional battery for all time recording?

[Sunny]

I remember from my young days, my buddies had serious car audio gears.
Multiple subwoofers, capacitors, lights dancing with music, exterior underbody lights etc... and the car battery was not able to handle all that.
I also had custom component system with a subwoofer and my car battery handled it but mine was not as power hungry as their's.
So they had additional Optima red/yellow Top battery in the trunk.
Not sure how they were charged though.
If it can handle all that, it can easily provide enough juice for multiple dashcams for 24 hour recording.

What say you?

 

[albertson]

I think this is a great idea if you have space for the battery. A full size battery may last days, depending on how many and which camera it is supporting. My Panorama2 has run 3 days in motion detect (and alarm system) and still left enough energy to easily start my car. Be careful to make a very secure mount for the battery so it does not become a danger in a crash. Use fuses and protect the wiring. A battery isolator will allow the second battery to be charged, and prevent it from discharging your main battery. Something like: http://www.waytekwire.com/item/80046/SURE-POWER-702-MULTI-BATTERY/

Trailers often have auxiliary battery to power the trailer accessories without draining the tow vehicle battery. They recharge while the tow vehicle is running.
This is a modification to the vehicle wiring, so it may not be a good idea if you are still under warranty.
Auto sound system shops could wire it for you, if you did not want to do it.