Home Marine batteries How to maintain marine batteries

Maintaining the battery of your boat is to prolong its life and avoid inconvenience during navigation. The lifespan of a battery depends on marine battery maintenance and your boating area. The principal causes of battery deterioration are lack of maintenance or insufficient capacity of a battery and poorly adapted charging equipment. Maintaining your boat’s battery is, therefore, as essential a task as boat maintenance.

Routine battery maintenance

The main cause of battery degradation is sulfation. When it is well advanced, we can observe white bloom at the pods. This causes a loss of efficiency. Sulfation often occurs when the battery, or dual purpose battery, has been discharged for several months. To avoid this, it is recommended to charge the latter as much as possible before winter or even to unplug it afterward. If the white bloom is already there, put the battery on a power surge for a few hours.

When you have an engine on a sailboat, and you only use the engine to get out of port, you drain the battery when you start. Moreover, when sailing, you do not charge it enough with the engine. In this case, do not change your sailing habits, but, from time to time, consider either running the engine, pushing buttery a little for a good 1/2 hour, or connecting a battery charger. Unless you are equipped with solar panels, wind turbines, or other generators.


Batteries, depending on their technology, are designed to accept deep discharge more or less easily. However, regardless of the battery, a shallower discharge is preferable. This means that your battery will give you more cycles and therefore have a longer lifespan if you discharge it less.


It is important to recharge the battery as soon as possible after use, as often as possible, and to 100%. When charging your battery, pay attention to the voltage: the charger voltage must match that of the battery bank. It is also necessary to consider the intensity in Amperes (A). It is this intensity that will determine the charging time. The lower the current of the charge, the more it will conserve the battery, but the duration of the charge will also increase.

Battery wintering

Winterizing a boat also involves winterizing the battery. Contrary to popular belief, the battery will discharge less quickly in the cold but will not like humidity. This one could as well be wintered on board or land.

A battery stored on the ground should be in a dry and cold place. It should be well charged before wintering.

A battery can winter aboard a boat too. There can be several causes. The first is to be able to run the engine from time to time during the wintering period and, at the same time, to recharge the battery. The second, a battery left onboard a boat equipped with a solar panel with a regulator, can remain charged throughout the winter. A 10 to 15 W panel is more than enough. Otherwise, if you have none of these, unplug the battery so that it loses minimal charge.

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