I have this little boat that we wear pan fish out with here near the house. One lake is 18 acres, the other is 100+. I only got about 4 years out of a lead acid battery that only runs the 40 year old trolling motor. I’d like to put money into a lithium battery, but unsure of what size would be appropriate. What would you think would work for a half day of puttering around?

I have a 50ah Lifepo off Amazon in our boat like that. It runs a 45hp trolling motor, helix 5 and the lights and bilge pump but we never run the lights or pump. My son has taken the boat out and fished several hours, no problems. Theyre $100 or less. I would recommend you get a charger specifically for litium batteries. Should get a 2-3yr warranty

Awesome, thanks!

Those batteries are really light, 10lbs or less. You can get a charger for around $15. These batteries do not compare to the other $400+ batteries. But for your application, theyre fine. I actually had one of these cheaper Lifepo batteries running our livescope on our bass boat. It worked great for over a year, then it went down and our second one went down in two months. My son wasnt chatging it after every trip and we were using our onboard charger. I got tired of fooling with it and upgraded to a better battery made for livescope. I really believe we were ruining the cheaper batteries not using the proper charger and letting it discharge fully before charging again. Theyre pretty good batteries but you have to treat them right. But in our smaller boat, the Lifepoe is doing great.

This battery has been flawless for me and it's made by one of the biggest Chinese companies. They aren't likely to go away.
https://a.co/d/1mtSP5g

This charger will work for it or most any other battery. I own 3 of them, but did have one to fail and they replaced it under warranty.

https://a.co/d/fJE6m3H

I won't say that you won't have any trouble with these, but I doubt you will. And if you do, I think the warranty will cover you. Some of the others might be just as good, but I don't have experience with them.

Do y’all feel safe charging a lithium battery inside? I feel like I’ve read some discussion about a higher fire hazard.

Millions of people charge them inside garages daily so yeah, guess so. They definitely had some issues with them early on hopefully those have been resolved. Part of the reason I waited a few yrs to get them.

I feel safe - I have the lithium battery in my phone on charge right now, and it's a bigger fire risk than the LiFePO4 batteries in my boat. The car battery fires we've all heard about are a very different chemistry than the LiFePO4 batteries.

Don't ask me to explain the chemical difference; I'm just parroting what I've read.