Power Pack Question ... Recommendations ...

[zer0netgain]

I'm looking for a power pack for my camera system.  It takes 4 AAs that don't last long and can add up fast.  The power adapter that goes with it converts from 12v.  So, I know I need a power adapter with 12v out as a feature.  The camera's always worked on a 12v circuit fused at 7.5 amps, so I know the output doesn't need to exceed that.  I'm still trying to lock down how many amps the camera draws when recording.

The best I can get from the manual is 4-5 hours with (4) AA alkaline batteries, up to 10 hours with (4) AA lithium batteries.

I'm not having any luck narrowing down what would do the job.  I was thinking it'd be nice if it could act as a pass-through power source so there's constant power regardless, but if the power pack will run the camera for 15 hours or more non-stop on a single charge, it'd not be a big deal to charge it normally at the end of the day.  I have no idea of what capacity I should look for.  

[Sport-Touring]

[zer0netgain]

Best calculations I can find presume the following....
1 AA = 2,800 mAh (max)
mAh remains the same if multiple batteries used in series
Formula is "Hours (H) = Ah / A"
So, 4 to 5 hours essentially means a drain not exceeding 0.65 amps.

If 2,800 is anywhere reliable, then I'm needing something in excess of 11,400 mAh capacity, correct?  Granted, I don't know what loss occurs in dropping from 12v to 6v.

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You can disregard.  The issue I was having that made me consider this option has resolved itself.