Need your input guys

They will be fine as long as the cells are the same manufacturer, size, type and quality (based on how many times they have been charged/discharged), the controller will see them as one 8000 mAh 5S pack. You should be fine, as the cells will discharge in unison.

[HotnCold]

And to be sure of the equal discharge of the batts - if possible use a battery balancer - to make sure all the cells in both packs are the same voltage... Happy running....