A marine battery charger, especially one for a boat, must be chosen carefully. It's necessary to know the input voltage for your battery, the battery type, as well as the capacity before choosing and there are other factors to keep in mind when actually charging also. Picking the right kind of charger is the key to making sure that an the battery has a long usage span.

It's important to keep in mind that you will probably be using a marine battery charger in a different area than a car or other type of charger. Marine equipment such as boats are mostly on the sea, not on the land, and as such you may have situations where you will have to charge the battery while you are away from shore. Choosing a charger that can easily be carried on the boat and kept safely is a must.

Coming across a charger that will not over or undercharge is also important. Charging a battery too much is the biggest cause of battery death, with undercharging following behind in a close second. Ideally you want a charger that will only have an output that is equal to 20 percent of the battery's total Ah capacity. Anything less will effectively undercharge the battery, and anything more will end up overcharging it. For example, if your marine battery has 100 Ah, then you should look for a marine battery charger that supplies 20 Adc.

If you have to buy a battery that does not give 20 percent of the total Ah capacity, then think about the times that will be needed for every charge. For example, if you charge a 100 Ah battery with a 10 Adc charger it will take just a bit over 6 hours. Similarly, if you charge a 200 Ah battery with a 20 Adc charger it will take the same amount of time. However, for a 200 Ah battery you would ideally need a 40 Adc battery charger, which should take no more than 3 and a half hours to reach full capacity. This logic works for all battery sizes, though the times will vary depending on battery size.

Using the right size of charger with your battery will make sure that it will last as long as possible. Marine batteries are not cheap, and a good charger than give your battery a second, third, or even fourth life for you to use. Consider the size and rate of your battery before getting a charger, as you will regret purchasing the wrong model shortly after. A marine battery charger is something that needs to be seriously thought over before being chosen, as they are all not only made differently, but they also come standard with different sizes and charge rates.