16ah lipo battery $50

Wow great deal.  Will the LIpo batteries have the potential to explode like the Samsung Note 7 batteries?  That has been my chief concern about the lithium batteries.

Or they might overheat, melting a hole in your kayak, and you'll end up like flight 370...

But, seriously, I use a lithium iron phosphate (LiFePO4, or sometimes given as LFP) battery because those cheap lithium phosphate batteries make me nervous.

Its never overheated in over 2yrs. of use.  If I want to, I can attach a low voltage alarm that stars buzzing (loud) if the battery voltage is below a preset value.  We kayakers are early adopters of these battery type.  Those who use and understand them enjoy the benefits.