In fact, while conducting this round of tests, we found flooded cells that had been minimally maintained with full recharges every four months during idle storage had still lost up to 30% of their capacity in only a year. If you fail to recharge them promptly, the sulfation process (change of active material to inactive material) takes a toll on capacity.You need good access (something some boats fail to provide) to check electrolyte levels.They need to be kept recharged to fulfill their projected life since they lose nearly 1% or more of their charge per day.They need frequent maintenance-or at least checking-to avoid having to replace them seasonally.They emit explosive gases (hydrogen) and can spew corrosive elements that can wreak havoc on surrounding structures.Those are the pluses now for the minuses. In fact, the best brands and designs-such as Trojan, Rolls and Surrette-are not expensive if you look at life-cycle costs they are actually cheaper than any other battery because they have the potential to last up to 1,000 cycles in real-world use. You can get four or five years out of top-quality brands-if you maintain them diligently. But it’s still essentially the same technology.įlooded cells are cheap, can be recycled, and (with TLC) can last more than several seasons. The battery cases have gone from rubber to the more-durable and less-electrically conductive polyethylene, and separator materials are better. The chemistry of a basic flooded cell battery has remained essentially unchanged for more than 100 years. We predict that the old unsealed battery is on its way out. Some newer batteries, however, do an admirable job in both capacities. A starting battery is seldom fully discharged a deep-cycle battery must withstand frequent deep discharges and recharging. A starting battery must be able to deliver very high current for a short period of time a deep-cycle battery must be able to deliver a more moderate current on a long-term basis. The two applications present different design problems to battery makers. Traditionally, a battery was designed for one of two applications-starting or deep cycle. Over the past few years, however, other types of sealed batteries have been introduced. Sealed batteries were once limited to “gel cells” in which the liquid sulfuric acid was replaced by a jelly-like semisolid. Sealed batteries force these gases to recombine, eliminating the need for refilling. This is the oldest design, and one that permits hydrogen and oxygen gases formed during charging to escape it also permits (and requires) periodic replenishment of the water lost. Unsealed batteries-also referred to as “flooded” batteries-have vent caps that are removable and open to the outside air. Without going into excessive detail, batteries have evolved into two main design classes-sealed and unsealed-and into two major application areas-starting and deep-cycle. What has changed is the physical structure of the battery itself. If you then remove the charging source and connect a load between the two pieces of lead, the process is reversed, and the battery delivers electrical energy. If you suspend two pieces of lead in a sulfuric acid solution and apply a charging current to them, one piece becomes coated with brown lead oxide, a process that absorbs electrical energy. The basic lead-acid storage cell was invented by Thomas Edison in the late 1800s, and the fundamental chemistry hasn’t changed since.
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