Battery size question?

Can anyone help with battery size?
How do I figure out what size Lithium Ion battery pack I need to run 2x 800watt hub motors? How long will it run? 48v
Thanks!
Steve

What is the amp draw of the controllers? The battery will need to be able to provide the combined draw from both.

2 factors

Power - need a large enough Ah capacity to keep the C-rates (both peak and continuous) within reason

Range - find out your avg Wh per mile, and decide how many miles per trip you want.