I've been looking at trolling motor batteries and have come to the conclusion I would rather spend $1,000 on 3 50Ah Lithiums that will last 10 years with a 5 year warranty than to spend $450 - $600 on 3 AGM batteries with a 1-2 year warranty. Not to mention the weight reduction in the boat. I swapped out my cranking battery for a 135 Ah battery 6 months ago and LOVE it.
Mind sharing where you found 3 Lithium 50ah batteries for $1000
Sorry it wasn't $1000, it was $1,295 including tax and shipping. I tend to round down when justifying purchases to myself.
It's from DrewCraft.com. The brand is Ionic. They actually use a really cool app that connects to your batteries and give you all sorts of data on the battery when you are close enough to connect to them via Bluetooth.