Giant portable battery with AC adapter input/output

Ok, this might sound like a silly idea but hey, I'm trying to think of creative ways

to add more surveillance and security to my life/house/car etc.

My car has a 2 channel camera system in it (front and rear cam) that record all the time

while I'm driving and parked. The problem is that sometimes I'm worried about draining the

car battery if I don't drive for 2 or 3 days. My cam system does have a SAFE SHUT OFF

as it detects when the car battery is getting low, it will stop recording and shut down on its own so as to not make the car battery dead and unstart-able. But I was thinking of possibly

adding 1 or 2 more cameras in the car without hooking it up to my car battery as there's already a lot of devices draining it while parked (i have a keyless smart system also which has to be able to communicate with my remote transponder).

Is there any such thing as a giant portable battery with AC plugs? What I mean is, I was thinking about using my cheap digital camera or camcorders, setting them up in my car via clamps or brackets and recording to SD/mini SD media. Now the cameras would have a fully charged battery (Li-ON) but as we know, cameras can only record around 1 to 2 hours continuously until the battery is completely discharged. 1 or 2 hours is not enough for a 24 hour day. Rather than to constantly recharge those small batteries in the camera devices, I would rather recharge say a GIANT ASS portable battery all day then at night put in my car, hook up my camera to it, and it could record say 6 or 8 hours straight using the giant ass battery instead of it's own tiny lithium ion battery.

Does anyone know if such a battery exists? I know they have those portable batteries for smartphones or other devices to recharge your phone or tablet etc. But don't they have portable batteries 20x that size (like the size of a UPS battery used for home computer systems). Or is that my answer? A UPS? Should I just use a UPS as my portable battery and plug in my camera to record all night?

You already have this giant battery you are referring to- Your car battery.

Automobile batteries store an incredible amount of power considering their size.

A "giant battery with a plug" would be a 12 volt battery hooked to an inverter which converts 12 VDC to 120 VAC.

I had one years ago that plugged into my car cigarette lighter and powered my Laptop for my wife to use on long trips. That is how your UPS works but none of them are designed to power anything all night. They are designed to allow all files to be saved and closed and the computer powered off in a short period of time.

What kind of battery you need and even if it is practical depends on the current draw of the equipment you plan to install. If it is too great then they will run the battery down depending on its capacity. My guess is equipment intended to run off house current may not be designed to minimize power usage as would be the case for things designed and intended to be used in an automobile.

Also- this giant battery you are referring to would be difficult and awkward to move in and out of the car on a daily basis. Plus the daily grind of recharging it, assuming the equipment you were using was even efficient enough not to completely discharge the battery during the time frame you want to use it.

My advice is first get a system designed specifically for use with an automobiles 12 VDC system. Converting 12 VDC to 120 VAC requires a given amount of "overhead" in the conversion process which would accelerate the discharge of the battery.

Second- get a 12 volt charger designed to tinkle charge your car battery. Some are made where they are permanently attached to the car and you merely have to " plug the car in" at night.

This would be a much more practical solution and as long as your chargers output met or exceeded the current draw of the car and your installed equipment then you would never have a dead battery to contend with. You would just unplug the car in the morning and plug it back in at night when you got home.

This would be a much simpler and reliable approach than trying to use equipment designed for home use and then trying to convert 12 VDC to 120 VAC with an inverter.

wow thanks for that reply. I don't know half of what you said but I think basically it means that there is no such thing as a giant portable battery that I can use to plug in my camera in the car? So, it's just easier for me to install a 2nd car battery?

Do you know how much drain a digital camera (point and shoot) while recording would have? Is it a lot of power or little?

you could get a second battery fitted in the boot and wire your gear to that one and have a PROPER AUTOELECTRICIAN put it together with proper fuses etc and wire up a crossover switch which will cut the connection to your main car battery thus the boot battery is the only one that will drain. then when driving flip the crossover switch to allow it to recharge.

I used to have a lot of stuff running off my car battery including an inverter.

I've found the best battery for something like this is a deep cycle battery. Optimas used to be my favorite, but I'm not sure anymore since Odyessy and Braille also make great competing products.

If you get a deep cycle battery with a high amp/hr rating, you should be fine. These batteries can power all your cameras for weeks without a worry. I once left my car in Chicago for 3 months at the airport. Came back and it started right up.