New toys

What you are looking at is a typical battery generator and the carbon monoxide sensor plugged in. This one is rated for 600 watts.

I plugged the sensor in at 100% battery for eight hours to get an idea of the power drain. I left this sensor plugged in for eight hours and I still have 92% reserved power.

This is what I will use to power all my devices, and it looks like 600 watts is a good compromise between size and cost.