Battery question

[FISH11]

I have a 12v 10amp hour battery, because I also run a bait tank off it. When I only use the fish finder it hardly uses any charge and it could run for like 4 to 5, 11hour days with one charge. When I use the bait tank with a 300gph pump it will run easy for over 14 hours because I use a timer that OEX sells (cost like $35). It's wired into the tank pump positive line and I programed it to run the pump for 25 seconds and shut off for 25 seconds. It just keeps repeating whatever time you program into it. That keep the water fresh, reduces the strain on the bait of constantly having to swim against a strong current and reduces the amount of charge the tank uses.