Need some help calculating V times mAh to make 12xAA 1.2v to 110v adapter.

[AaronASB]

So I want to use a 12v to 110 household adapter. I have one that is 300 watts. And I am not looking to get 300w at 110v though.

Question is; If I hook up 12 1.2v aa rechargeable 2700mAh powerex batteries.

Does that equate to 3.24 watts per battery for one hour?

Meaning if I hook up 12 of them together can get 38.8 watts at 110v for 2.7 hours?

How do I do this math? I did 12 x 1.2v times 2700mAh which is 12*V*A = 38.8 total watts for 2.7?

 

[Mr Happy]

You can conservatively assume the capacity is 2500 mAh rather than 2700 mAh. Then the power capacity of each cell is 1.2 V x 2.5 Ah = 3 Wh (three watts for one hour).

However, to deliver 3 W in one hour the battery would have to be discharged at the 1 hour rate, which is 2.5 A. That is a heavy load for a 2700 mAh cell. Conservatively you probably should not go above 1.25 A or so, which means 1.5 W for 2 hours.

If 1 cell will supply 1.5 W for 2 hours, then 12 cells will supply 12 x 1.5 = 18 W for 2 hours.

Now your power inverter is likely not very efficient, so do not expect to get 18 W out the other side. I would guess maybe you can get about 12 W out with 18 W in. Perhaps a little more if you are lucky. So you will not likely be able to run any power hungry devices.

 

[Benson]

No, but yoiu can get 38.8W at 14.4V for 1 hour, or 14.4W at 14.4V for 2.7 hours. (Assuming the batteries give full capacity at 1C or 0.3C discharge, respectively. Probably a little less...)

What power you get at 110V depends entirely on the efficiency of your inverter, but is bound to be less than the power at the inverter input.