Generally speaking there are two different types of lead acid battery, Starting and Deep Cycle. If a starting battery is routinely deep cycled (discharged below 20%-50% of max capacity) it will generally fail after 30-150 cycles. The same starting battery will last for thousands of cycles if it is just used normally (2% - 5% discharge).
These phosphates precipitate the solids to the bottom of the boiler drum. At the bottom of the boiler drum there is a bottom blow to remove these solids. These chemicals also include anti-scaling agents, oxygen scavengers, and anti-foaming agents.
Swimming pool chemicals may also be used in hot tubs, spas, wading pools, and whirlpools. Various kinds of disinfectants and sanitizers are used but the chlorine type is the most common. The chlorine usually comes from chlorinating agents that release chlorine when they are dissolved in the water.