Tips to extend the life of your marine batteries

As I stated above, batteries die early because of overcharging, undercharging, fully discharging, sulfation, extreme temperatures, and un-proper seasonal storage. Below, I explained how to avoid each of these issues properly.

Additionally, if you have a wet cell (flooded) battery, you will need to maintain it by refilling the cells with distilled water regularly. If you don’t, the battery will have a significantly shorter lifespan.

Don’t overcharge your battery

Although many batteries nowadays have sensors that prevent your battery from overcharging, these fail. Don’t entirely rely on those sensors because overcharging a battery can harm the battery and be dangerous.

Overcharging a battery:

Increases the risk of a short circuit and an explosion

Can create unstable conditions inside the battery

Causes a loss of sulfuric acid and distilled water within the battery

Heats your battery up and can cause permanent heat damage

Can cause corrosion on the positive battery plates

Gel cell marine batteries deep cycle are the most susceptible to overcharging because any lost water cannot be replaced. However, all batteries can be damaged by overcharging, so it’s always recommended never to let it happen.

Don’t undercharge your battery

Just like how overcharging your battery is bad, undercharging it could also have damaging effects. So, Always charge your marine battery to full before unplugging the charger.

Not fully charging a battery can cause sulfation which worsens the battery’s performance and shortens its lifespan.

We recommends to always fully recharge your battery after use and before storing it. You should also charge your stored battery to full every few weeks as batteries drain power in storage.

Don’t fully discharge your battery

Irriversal damage can occur if you discharge your marine battery past 50%, but it probably won’t be detrimental. Just try never to go below 30% because that will definitely damage your battery. This is especially true with lead-acid batteries, including wet cell (flooded), gel cell, and AGM batteries.

People who just use their marine batteries for starting their boat and basic electrical accessories won’t run into this issue until they store their boat for a long period of time. In that case, I recommend charging your battery every 2-3 weeks to full or properly set up a trickle charger such as this one.

Other people who will run into this issue are ones that use trolling motors. Trolling motors drain your batter and because you usually don’t have your gas engine on at the same time, the battery won’t receive any power.

So it’s important to check your battery percentage often if you plan on running a trolling motor for an extended period of time. Try to avoid going any less than 50% charge. I recommend getting one or two extra batteries for a trolling motor, preferably a lithium one (such as this one on Amazon) as they are affected less by extreme discharge.

Make sure to store your battery properly

During the off-season, it’s important to know how to store your marine battery properly.

The first thing to do is disconnect your battery’s negative cable and charge the battery fully. You’ll also probably want to refill the fluid levels if you have a wet cell (flooded) battery. You’ll then want to charge your battery to full at least once every 2-3 weeks or trickle charge it properly.

And, like what I mentioned above, make sure you store the battery at room temperature.