I've been trying to determine how long a 100ah battery would last for a particular situation but I am failing to understand somewhere. I thought I read that it is Battery Ah / Amps of device. I did some googling of electric smokers and someone mentioned 1400 watts which would be about 12 amps. So 100/12 is 8.3 hours. But then I was watching Will Prowse on calculating runtime and he mentioned a 100ah battery is 1200 watt-hours so you could run a 1200 wayt device for 1 hour. So then I got confused. In this case a 1400 watt smoker would not even last an hour. Where am I going wrong, or what am I figuring incorrectly?