Battery selection and maintenance is critical. Next to the basic motor itself your battery is probably the most important item in the chain of equipment - and the one most likely to wear out first. After all, it's the source of power that runs the motor.

There are several types of battery construction available. They range from conventional lead acid designs to a wide variety of dry cell models. A technical discussion of battery construction is beyond the scope of this article. It is important to consider your options, however.

The most common type is lead acid. Lead acid batteries come in several designs, including those called wet cells. Some wet cells are sealed and require no internal maintenance. Others require internal maintenance, adding water. Either way, a wet cell, lead acid battery is considered to be conventional. It's the type you will most likely be using.

There are other versions of lead acid batteries. Some are known as gel cell, others are called AGM (Absorbed Glass Mat) batteries. These designs last longer and will survive more charge-discharge cycles. They are also more expensive and heavier. Some models require special chargers.

There is also a vast array of dry cell batteries on the market. Once again, they may last longer, but they aren't cheap. They may also require special chargers.

Regardless of what type of battery you select, do not run your electric motor with a cranking battery. Cranking batteries are engineered to deliver a high amount of power quickly. Deep cycle batteries, on the other hand, are engineered to deliver power at a lower rate over a long period of time. They will also withstand repeated charge-discharge cycles, something a cranking battery can't do.

Buy the biggest, most powerful battery you can afford so long as it will fit into your boat. Even deep cycle batteries are damaged by serious discharges and repeated overuse. The more powerful the battery, the less discharge it will suffer over a day's fishing.

Lead acid batteries require maintenance. There are no shortcuts, nor are there any excuses, that will paper over - or make up for - a lack of routine maintenance.

Experts recommend cleaning the battery posts and terminal connections regularly. Treat them with a corrosion-resistant compound.

If your battery is not "maintenance-free," check the water level after each use, or at least on a regular basis. Every two weeks is a good place to start. Add distilled water as necessary. Do not overfill. Never use or charge a lead acid battery that is low on water or electrolyte.

Charge your batteries immediately after use. Allowing even a day before recharging can permanently harm the battery.

And, speaking of charging your battery . . . Do not skimp on a charger. Get one of the best. Most anglers prefer onboard chargers that are mounted in the boat. They can be plugged into a standard outlet at the house, garage or dock. Follow the manufacturer's recommendations for specific charging procedures.

Select one that will charge your batteries within a reasonable length of time, say 12 to 16 hours, and that will automatically reduce the rate of charge as the battery reaches its peak. Most top chargers need not be unplugged. They will sense the state of charge in the battery and supply current as required.

These few paragraphs only scratch the surface of what you need to know about batteries. For more detailed information visit www.batterystuff.com. It's full of information that is technical, informative and practical all at the same time.