UPS (battery backup) for security camera system. what do i need?


Diamond Member
Dec 27, 2001
i plan to get this security camera system
total cameras. each cam uses on average 15watts, so maybe max of 200watts for the whole system (NVR+ 10 cameras).
what UPS do I need in order to power this system for 1hr, 3hr, or even 5 hours? how do i calculate such? what specs to look for when buying UPS?
i was thinking of getting a portable power station like this but those cannot output power while the station is plugged in to recharge.

Red Squirrel

No Lifer
May 24, 2003
Off the shelf UPSes are not really designed for long run times, so what I'd do is look at an inverter-charger and a couple deep cycle marine batteries. Golf cart batteries are great too. Inverter-chargers essentially work the same as a UPS but allow you to connect bigger batteries.

This is the one I use for my servers, although there may be much newer ones available now days:


Platinum Member
Jun 14, 2012
I run my wireless VOIP phone, router, modem, and two monitors off a 20 year old 450 watt, 650VA APC unit (about 200 watts). The computer runs off an APC SUA750. The computer will run a little over an hour or so. Then once the monitors shut off, the smaller UPS will power the phone and modem/router all day.

I once tested just modem, router, and phone. It powered it 16 hours, and was still going. Remember, those wattage numbers they are giving you are MAX. It won't nessesarily draw that all the time.

By comparison, My previous Cyberpower 1200VA UPS would only run the computer for 10 minutes. Cheap APC's are about the same. SUA units are far superior, but expensive.

Personally, I wouldn't charge deep cycle batteries in my home. They off gas continuously. Maybe in a garage.


Diamond Member
Aug 11, 2001
^ The off gassing is mostly a byproduct of overcharging so if your charger doesn't do that, and you check it every now and then, it's not likely to be a problem.

I've had a marine deep cycle in an unfinished corner of my basement for a battery backup sump pump for as long as I've been in present location (around 20 years), only issue was that the last (but not prior) time the battery failed, and started to outgass, it smelled like sulfur. Funny thing was that at first, I thought I had some issue where it was gas backfeeding from the sump system, maybe from a broken sewage line but nope, was just the battery.

At the same time, sealed lead acid batteries exist so I would sooner choose those for a living area.

ALSO, the PDF spec sheet for those cameras linked on Amazon, shows they are <12W each, powered by a DC 12V, 1A PSU so they are probably really 8W each or less, average consumption. This can be measured.


CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
200W @ 1 hour @ 12V = 16.6667 AH battery.

So you need something that can use about twice that, or 1/2rd more then that from inverter loss and other efficiency stuff.
That means you need a 24-32 AH battery type.

That is going to be tough, because that unit will probably cost more then your cameras, as high AH UPS's are also high VA ups, which in turn are high Wattage UPS = Rack mount $$$$.

I think you will be fine with anything on this list that is at least 1000VA.

As each of the 2U rack ups's house 6 x 12v/7aH AGM SLA batteries for a total of 42aH.
Well some use 3 like the Liebert series, but 3 x 7 is 21aH.
It might make the cut.
Last edited: