5 picks with specs, filters and a calculator to find the right size.
Sealed and spill-proof and far cheaper up front than lithium. Plan on using about half the rating, and expect them to be heavy.
A dual-purpose battery that can start an outboard and run electronics. Optima’s spiral-cell design handles pounding and vibration well.
Best for: Boats that need one battery for both starting and accessories.
Check price on Amazon (paid link) Specs from pdf.nauticexpo.comA true deep-cycle AGM built for trolling motors. Recharge soon after each trip to get the most cycles out of it.
Best for: Budget trolling motor banks.
Check price on Amazon (paid link) Specs from batteryequivalents.comA sealed, maintenance-free AGM from Renogy’s solar line. It discharges down to 5°F, but like lithium it should only be charged above 32°F.
Best for: Solar and house banks on a budget.
Check price on Amazon (paid link) Specs from renogy.comA widely sold 12 V 100 Ah sealed AGM. It works for trolling, solar and backup power.
Best for: An affordable 100 Ah AGM.
Check price on Amazon (paid link) Specs from homedepot.comA small 12 V sealed battery for kayak trolling motors, electronics and backup use where a full-size battery is too heavy.
Best for: Kayaks and light-duty use.
Check price on Amazon (paid link) Specs from zoro.comNo products match those filters. Try clearing one.
Pictures are our own illustrations, not photos of the actual products. Specs come from the manufacturer or retailer listing linked on each card and were checked in October 2026. Models and prices change, so confirm details on the listing before you buy. As an Amazon Associate I earn from qualifying purchases.