Boat Battery

Welcome to the Boat Battery website. We aim to guide you towards the best information on the web for your Marine Battery purchases.

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Marine Batteries

One of the major causes of failure of marine batteries is the incorrect type being used, the wrong size, or a poor quality boat battery being fitted. One needs to fit the right size boat battery to fit the crafts requirements, anything less might work for a short period of time but is likely to let you down just when you need it most. A good quality marine battery is not cheap, and a lot of boats are sold with the lowest quality battery the retailer can get away with. This is not always the case, but always check the quality of the boat battery when buying a vessel, and ask for an upgrade if you are not happy.

Batteries, although looking pretty simple, are actually quite a complex topic. As a boat owner, it is vitally important that you have a fundamental understanding of boat battery basics. Knowing how a battery works (or doesn't work) is something we'll take a brief look at here, there is plenty of detailed information available online, I urge you to find it. I will be providing some detailed articles on this site at a later date. When we talk about marine battery application, it means the battery use in the type of boat or trolling motor you have. construction is simple, it involves how the battery is constructed.

The use of the electronic boat battery charger, now the prevalent type these days virtually eliminate the risk of overcharging. They provide a 3 stage charging routine and use electronic sensors to monitor the charging process and prevent the boat battery being overcharged. An old electric charger may well be the cause of damage to your marine cycle battery if you are experiencing power problems. Unusual fluid loss and a hotter than usual battery rate likely signs of overcharging.

Boat Battery Design

The humble marine battery is the central item in the electrical system of all pleasure craft. Most boats have a simple 12 volt DC system. The marine battery is usually set in banks of one, two, three, or four industrial batteries which hare connected in parallel. A larger vessel may have a 24 or 36 volt marine battery system. In general, each battery is utilized to start one engine, but it is also wired to a battery selector switch. This switch may be marked 1, 2 ,or ALL. The selector switch controls which battery bank runs the house system. Modern yachting codes state that all boats must have a master shut off switch for safety reasons.

The use of boat battery parallel switches join two batteries together which results in a doubling of amperage but not a doubling in voltage. If both batteries are low they may start an engine that fails to start on a single bank but this is not always the case, hence the need to ensure that marine batteries are well charged and in good condition.

Marine Battery Types

There are a number of types of replacement lead acid sealed batteries, and they are not all created equally. Automotive or Starting batteries, Both marine cycle batteries and deep cycle batteries are very different creatures. Real deep cycle batteries have extremely thick plates, and are much heavier duty than the hybrid pseudo deep cycle batteries that are often found on sale or for use as golf cart batteries. In fact, the thickness and composition of the battery plates are the major contributor to cost.

Cycling is the period of discharging and recharging the battery, and the life of a battery is determined by how many times the cycle takes place. An automotive battery is designed to withstand 5% discharges, whereas a deep cycle unit can withstand 50% discharges without sustaining damage.

The starting or automotive battery is often found in entry level boats and are touted as marine batteries (sometimes called auto/marine). The problem here is that an automotive battery is designed to be constantly trickle charged by your alternator, thus avoiding discharge rates or greater than the safe 5%. The sort of batteries marine vessels should use is likely to be a deep cycle battery, although hybrids are common.

The Deep Cycle Boat Battery

The plates will be thicker than the automotive types but not as thick as a true boat battery. As mentioned, marine deep cycle batteries can tolerate 50% discharge, your industrial deep cyclers can take an 80% discharge without permanent damage. An automotive battery will suffer irreparable damage at these rates. So just because the boat battery you have is labelled auto/marine, don't assume that it is going to do a great job. There is really no way of telling unless you cut it in half.

For quality products, Amazon  are hard to beat. They offer a great range of boat batteries  from reputable manufacturers like Optima and MRG. as well as accessories like the boat battery charger and selector switches.

On this basis, it is important that you check the marine battery you have in your vessel and try to determine the quality of it. If in doubt replace it with a bespoke boating battery which should provide you with good, reliable service providing you give it the corect maintenance. Taking a chance with a boat battery is a bad idea, and many a sailor has come undone on the water by trusting a defective boat battery.