Sediment. Loosened or worn out particles of active material fallen to the bottom of cells; frequently called "mud".
Sediment Space. That part of jar between bottom and top of bridge.
Separator. An insulator between plates of opposite polarity; usually of wood, rubber or combination of both. Separators are generally corrugated or ribbed to insure proper distance between plates and to avoid too great displacement of electrolyte.
Short Circuit. A metallic connection between the positive and negative plates within a cell. The plates may be in actual contact or material may lodge and bridge across. If the separators are in good condition, a short circuit is unlikely to occur.
Spacers. Wood strips used in some types to separate the cells in the case, and divided to provide a space for the tie bolts.
Specific Gravity. The density of the electrolyte compared to water as a standard. It indicates the strength and is measured by the hydrometer.
Spray. Fine particles of electrolyte carried up from the surface by gas bubbles. (See Gassing.)
Starting Rate. A specified current in amperes at which a discharged battery may be charged at the beginning of a charge. The starting rate is reduced to the finishing rate when the cells begin to gas. It is also reduced at any time during the charge if the temperature of the electrolyte rises to or above 110° Fahrenheit.
Starvation. The result of giving insufficient charge in relation to the amount of discharge, resulting in poor service and injury to the battery.
Strap. The leaden casting to which the plates of a group are joined.