What type of battery is recommended for deep cycle marine use?

For deep cycle marine use, AGM (Absorbent Glass Mat) or gel batteries are highly recommended due to their specific design tailored for applications where deep discharges and recharges are frequent. These types of batteries are more resistant to the stresses of repeated deep cycling compared to other battery types, making them ideal for marine environments where energy needs can fluctuate significantly.

AGM batteries, in particular, have an advantage because they are sealed and do not vent gases, which means they can be installed in a variety of orientations without risk of leaking. This is especially useful on boats where space is limited and situations may arise that can affect the battery's position. Additionally, these batteries typically have a longer lifespan and can handle higher discharge rates than standard lead-acid batteries, enhancing their reliability in powering marine electronics and other equipment.

Gel batteries also offer a similar benefit in that they are sealed and maintenance-free, providing good performance in a deep-cycle application and minimizing the risk of sulfation, which can occur when a lead-acid battery is deeply discharged and not recharged promptly.

While lead-acid batteries in general can be used for deep cycle applications, they require regular maintenance, such as checking water levels, and are more susceptible to damage from deep discharges.