As many articles introducing Marine batteries, there are three main types of it including Flooded-battery, Cell-battery and Absorbed Glass Mat (usually known as AGM). Each type has their partly advantages and disadvantages at the same time. The consideration is that you should select flood, wet or AGM for your boat for the best usage. They depend on the kind of boat, how you use and your investment.
- Flooded batteries: are the most common and cheapest types of battery designed for marine tools. Regarding the action process, they use a reservoir of liquid sulfuric acid to act as a pathway between lead plates. Then, electrolyte produces hydrogen and oxygen when battery is charged. This step requires vented boxes and compartments in order to have gas escape safely outside the boat. Depending on the heat and extra gas produced during the charging process, wet items will ask periodic inspection and topping-off with distilled water. Their self-discharge stays at higher rate about 6%-7%/month than the rest. This is highly considered for not tolerate high amounts of vibration and better overcharging-control than other. The main disadvantage of it is no maintenance-free, leading the duration time shorter.
- Gel batteries: are the combination of sulfuric acid, fumed silica, pure water and phosphoric acid. This mixture battery is quite viscous and prevents leaks in case the battery is inverted or damaged. The charging does not result in a small amount of oxygen and hydrogen as well to be generated at the plates. However, the pressure inside the cells will combine with the gases and create water. They are called as recombinant batteries as the result. By this way, the battery is kept from drying out due to charging. Hence, they charge a lower voltage than flooded or AGM batteries and require a vessel’s charging system that should be carefully regulated to avoid the high voltage overcharging.
- AGM batteries: Absorbed Glass Mat batteries have glass mat separators saturated with acid electrolyte among positive and negative plates of the battery. In time of charging, pressure from valves allow oxygen that is produced on the positive plate to migrate to the negative plate and recombine with the hydrogen, producing water. This type of batteries has better shock and vibration protection than wet or gel types and also saves maintenance-free. Another advantage of the AGM batteries is they have lower internal resistance, being more adaptable for starting and charging acceptance as well as quicker recharging than any types of deep cycle batteries. AGM batteries are possible to accept the highest charging current, up to 40 % of the amp-hour capacity of it. It has long life, outstanding performance and faster recharging. They make AGM batteries become great dual-purpose batteries for fishermen who want to have quick starting power and reliable deep-cycle ability. That is the reason why the price of it is higher than other.
However, for any reasons, AGM batteries are preferred than the rest despite their higher price. They can match any requirements that a marine batter needs to have.
How to have good charging of Marine batteries
- Have shallow discharges lead for a longer battery life. Also, you should invest in a solar power trickle charger with a smart regulator for better usage of your battery.
- Please remember that 80% is the number of discharge that gives you the maximum safe discharge for your deep-cycle batteries
- Never leave batteries deeply discharged for any length of time. Because, you are damaging and making your batteries at lower capacity if leave batteries in a discharge state.
- After every using, you should charge batteries. And also, never mix old batteries with new ones on the same charging system. Old ones will tend to pull down the new in the battery bank to their deteriorated level.
- Always keep your batteries in acid-proof storage boxes that are secured with tie downs.
- Be necessary to maintain fluid levels in wet-cell batteries. You can use them for golf cart or traction propulsion batteries if you have a true deep-cycle one.