If you haven't been charging the battery as soon as you get home, then it may have created a memory. If it holds a load, it may just need to be cycled (used and recharged) a time or two to restore the full charge. It could have irreparable damage though if it's been left at a low charge for very long.
Always recharge your batteries as soon as you can. Most people leave them with a low charge, and try to charge them just before their next fishin trip. That's the worst thing you can do to a DC battery. I charge mine ASAP!! I plug mine in before I get my fish out of the boat!!! They last 5-7 yrs. that way, some longer.
We only sell the Best. Ranger, Xpress, Yamaha, Suzuki, Tohatsu.