Amped Outdoors (formerly Energized Outdoors) Lithium LifePO4 batteries. Perfect for Kayak, small boat, ice fishing, trail camera external batteries and any other electronics needing reliable and long lasting DC battery power.
Lithium batteries are also ideal Kayak fishing batteries because of their lighter weight and the fact that you get more usable power from each charge. Not to mention up to 5 times as many charge cycles compared to AGM/SLA batteries you can see how they will actually be cheaper in the long run.