Most modern boat battery chargers use a smart charging technology or sometimes called the “accurate voltage control charging” or 3-step charging. Three step charging works by charging it first with a high current followed by a low current and a much lower current. Finding an on-board boat battery chargers or a charger that is part of the inverter-charger system that can be installed permanently to your boat is very easy. However finding a quality charger that can be used for outside the boat, for example retrievable boats or around the house or garage is more difficult.
Portable smart chargers usually have alligator clips to temporarily attach it to the battery you wish to charge. It has a built-in protective circuit that send and error code just in case you mistakenly inverted the positive and negative poles eliminating the risk of damaging both the battery and the charger. It has a built-in selector switch that allows you select with the different types of battery like AGM, wet cell battery or gel cell battery. You can also choose the temperatures like 95, 35 or 65 degrees F, because all battery charging is temperature dependent, meaning you can use it in all kinds of weather condition from freezing cold climate to tropical hot. You can also select how you want to charge it like 2 amps, 10 amps or 30 amps and it also have a digital display which shows the options you are selecting. It also has LED indicator lights so you can easily see what is going on and the status of the charger and the battery.
Most problem with flooded battery when you use it a lot, charging it back and forth after a while they need equalization, so some charger has a built-in equalization cycle on them. It can also be used as a battery booster just in case you’re having a problem starting your car. When the battery is then fully charged, it automatically goes into float or maintenance mode to avoid overcharging the battery. You can choose from different sizes like 30 amps, 15 amps, 6 amps or the smallest 2 amps maintainer. The unit has a cable compartment so you can just put the cable inside when not in use, very neat. It has a foldable handle so you can carry it anywhere.
The common problem with boat battery charger is when you purchase and install an under rated charger. Not only it will take too long to charge but sometimes it will cause malfunction. Almost all marine battery charger have built-in overcharge protection circuit, a built in timer monitors the time it takes to charge the battery. If it takes too long to charge it will automatically shut the system to protect it from over charging. Other problem is when you use a charger that is not compatible with the type of battery you are using.
Most modern chargers are compatible with different types of battery, like the Gel Cell batteries, all types of lead-acid, flooded or sealed maintenance free batteries but definitely not the Black and Decker Batteries for cordless tools. It has a selector switch that allows you to choose between different types of batteries, different type of batteries has its own program. When you buy a new unit it usually comes with the mounting brackets and the wire needed to connect it to the battery. They are usually only about 4 feet long, so if you want to install it away from the batteries you need to extend or replace them with a longer one. They also have short cord plug, so you need to have a long extension cord. If you want you can also wire it permanently using a marine on-board inlet.
Another thing to consider when choosing the best 3 bank marine battery charger for your boat is that it should be able to withstand any kind of weather condition. Choose one with waterproofed, shockproof corrosion and rust resistant features especially if you are going to use it in salt water environment, one that can withstand extreme ambient conditions including moisture, vibration and shock. There is also solar boat battery charger that you can purchase which is very handy in case of emergency while in the middle of your boating trip where there’s no electrical outlet available.