The Cabella's battery is called a VRLA battery....valve regulated lead acid.....it's a sealed lead acid battery...aka SLA.
I can't vouch for the Harbor Freight, 0.7 amp charger, but for my money the Schumacher, #SEM-1562A, 1.5amp battery maintainer/trickle charger is a superior charger for around $27 at Walmart or Amazon.
This charger can be left on a battery indefinitely owing to the smart chip, that monitors the state of the battery in the charge and automatic trickle modes.
I have 3 of these units and they are reliable over the last 4 years.
Tight lines
The attached photo is my old Outback taken in 2013. You can see the Humminbird mounted on the right side, within easy reach for viewing and adjusting the screen.