LiFeP04 ah vs lead acid batteriesah

[Mailc4man]

I am trying to figure out how many ah I need if I switch to a lifep04 battery. My current battery is a lead acid deep cycle marine with a 109ah rating. I know I don't need as many ah with a LiFeP04, but not sure how many ah I would need. I only use it for a small light weight Jon boat, and usually run my trolling motor for a max 2 hours on the river, sometimes run my lights. What I have now works great, but I want to lighten my load. Any suggestions?

 

[Butthead]

What size trolling motor, what size boat?

 

[Mailc4man]

What size trolling motor, what size boat?

12 ft jon boat, but small light weight only 3ft wide, 55lb thrust trolling motor