Has anyone used one of these

to power a fish finder.

I'm thinking all you would need would be one of those DC male out to alligator clip accessories (and the correct fuse).

What's the link to the power supply. Sounds like something I need for my portable live well.

Seen a video of someone running their trolling motor off one

I already have a specialized charger for lithium batteries, but these lithium jump starters have a self contained charging 110volt plug in system

My concerns:
The obvious potential water + lithium issue
These batteries are really designed for jumping/cranking

The concern is warrented - a lot of the jump start lithium batteries don't have good heat dissipation for extended use.

Collin - read through the builds I did for myself -
i used a USB lithium setup for the second one Battery Box Builds

while sorting those builds out - I actually looked at a number of the jump starter lithium... as well as some of the nicer lithium batteries that had 12v leg output and ended up not using them due to expense and it being more flexible to go the standard USB route.

Thanks, I have that exact same Battery Tender Lithium battery (been using it for three years now, and it's great).

Always looking for cheaper alternatives for more amp hours

Found one that looks maybe more promising (it's designed to power big drones)