Boat Batteries: Why Choose Gel?

Marine batteries are used to power a boat's lights and electronics. There are four different chemical types of marine batteries: wet cell (flooded), gel cell, absorbed glass mat (AGM), and lithium. The type of battery used depends on the boat owner's needs, the capacity and lifespan they require, and their budget. Gel batteries are sealed, meaning they will not spill even if the battery case cracks or breaks. They are also known as dry cell, non-spillable, regulated valve, or maintenance-free batteries. However, gel batteries are sensitive to charge voltages above 14.1 volts DC at 68 degrees. If the charge cycle is not well-regulated, the battery may be damaged.

Gel batteries are non-spillable

The gel battery will not spill, even if the battery case cracks or breaks. This is because they are deep cycle batteries that have an electrolyte suspended in a gel solution between the lead plates. This makes them ideal for use in places with little ventilation.

The gelled electrolyte will absorb water, which keeps the closed system hydrated. This is due to the gel undergoing a chemical reaction, heating up, and liquefying. During the cool-down phase, the gel solidifies and tiny hairline cracks form between the gel and the battery's plates.

Gel batteries are extremely sensitive to charge voltages above 14.1 volts DC at 68 degrees. If the charge cycle is not well-regulated, the battery can be cooked for good.

Gel batteries are sealed

The gelled design of these batteries prevents them from spilling or leaking, even if the battery case cracks or breaks. This makes them ideal for use in boats, as well as in wheelchairs and medical mobility batteries. They are also known as dry cell, non-spillable, regulated valve, or maintenance-free gel batteries.

The gel batteries' sealed cases undergo a recombinant chemical reaction during recharging, where oxygen and hydrogen recombine inside the battery. This reaction is achieved through a gas phase transfer, where oxygen migrates to the negative plates and is absorbed, suppressing the production of hydrogen gas. This design prevents the escape of gases under normal operation and helps retain moisture inside the cell.

Gel batteries are more expensive than other types of batteries and have specific charging requirements. They are extremely sensitive to charge voltages above 14.1 volts DC at 68 degrees. If the charge cycle is not well-regulated, the battery can be damaged.

Gel batteries are maintenance-free

Gel batteries are indeed maintenance-free. They are lead-acid batteries with added silica to create a gel-like substance. This means that they can be installed in a variety of positions and don't emit as many fumes, making them suitable for applications with limited ventilation.

Gel batteries are sealed with a valve that removes excess pressure. This, along with their gel substance, means there is no chance of leaking. This is especially beneficial when compared to wet cell batteries, which are also sealed in a plastic encasement but can still leak.

Gel batteries are also generally maintenance-free, which means they can be used in a wide range of applications and installed anywhere. They are also vibration-resistant, which is a common complaint with wet cell batteries. The gel substance in these batteries also means there are minimal fumes created during use, reducing the need for ventilation.

Another benefit of gel batteries is that they are resistant to discharge death. Wet cell batteries can never be recharged if they are allowed to discharge too much, but gel cell batteries are deep cycle batteries, meaning they can discharge more and still be recharged like new.

However, it is important to note that gel batteries are more expensive than wet cell batteries, and they also require extra charging time. They are sensitive to charge voltages above 14.1 volts DC at 68 degrees, and if the correct charger is not used, you can expect to get about half of the battery's rated life cycle.

Gel batteries have a low self-discharge rate

Gel batteries are a common type of battery used in boats and other vehicles. They are known for their safety and low maintenance, as they do not spill even if the battery case cracks or breaks. This makes them ideal for boats, as any jerks or splashes will not cause battery spillage.

One of the key advantages of gel batteries is their low self-discharge rate. Self-discharge refers to the battery's loss of charge over time when not in use. This is an important factor to consider when choosing a battery, as too high a self-discharge rate can limit the battery's applications.

Gel batteries have a self-discharge rate of about 4% per month, which is significantly lower than that of flooded batteries, which can self-discharge at rates of up to 8% per month. This low self-discharge rate gives gel batteries a longer shelf life and makes them suitable for applications where the battery does a lot of sitting and less sailing, such as boats that are used infrequently.

The low self-discharge rate of gel batteries is due to their unique construction. The gel batteries use an electrolyte that has been thickened to a gel consistency by adding a silica agent. This gel undergoes a chemical reaction, heating up and liquefying, then cooling and solidifying, forming tiny hairline cracks. These cracks allow for the transport of hydrogen and oxygen gases produced during the charging process between the positive and negative plates. This results in a closed system where the gases recombine to form water, keeping the battery hydrated and reducing the self-discharge rate.

The low self-discharge rate of gel batteries makes them a popular choice for marine applications, as it ensures that the battery will retain its charge over time, even when not in use. This feature, along with their safety and low maintenance, makes gel batteries a common and reliable choice for boat batteries.

Gel batteries are sensitive to high voltages

Gel batteries are indeed a type of boat battery. They are valve-regulated, maintenance-free, lead-acid batteries. They are robust and versatile, producing few fumes, and can be used in places with limited ventilation.

It is important to select the right charger for gel batteries as they charge at lower voltages. The term gel cell is often used to refer to sealed, maintenance-free batteries, which can be confusing when choosing a charger. If using other charging methods, such as alternators, proper regulators must be installed to control the charging voltage.

Gel batteries are also sensitive to high temperatures, which can adversely affect their performance. The heat produced during overcharging is more efficiently lost in gel batteries compared to AGM batteries due to better heat conduction from the plates to the cell walls. However, at high operating temperatures, gel batteries can suffer from water loss.

In summary, gel batteries are sensitive to high voltages and temperatures, and it is important to use the correct charger and regulator to ensure optimal performance and longevity.

Frequently asked questions