Batteries with sealed jars are generally shipped completely assembled and filled with electrolyte, and need only a freshening charge before being put into service, just as automobile batteries which are shipped "wet" are in a fully charged condition when they leave the factory and need only a charge before being installed on the car.
Jars that are not sealed are set in separate glass trays filled with sand, or sometimes the entire battery is set in a shallow wooden box or tray filled with sand. This is necessary because the absence of a sealed cover allows acid spray to run down the outside of the jar and this acid would, of course, attack the wooden shelf and make a dirty, sloppy battery. Batteries using jars without sealed covers cannot be shipped assembled and charged, and hence they require a considerable amount of work and along initial charge to put them in a serviceable condition.
Farm lighting battery jars are less liable to become cracked than those of automobile batteries because they are set in one place and remain there, and are not jolted about as automobile batteries are. Cracked jars in farm lighting batteries are more easily detected as the jar will be wet on the outside and the acid will wet the shelf or sand tray on which the jar rests.
Batteries with sealed rubber jars are normally assembled four cells in a case or tray, with a nameplate on each tray which gives the type and size of cell. The cells are connected together with lead links which are bolted to the cell posts by means of lead covered bolt connectors.
Plates. Since farm lighting batteries are not required to deliver very heavy currents at any time, the plates are made thicker than in starting batteries, this giving a stronger plate which has a longer life than the starting battery plate.
All makes of starting batteries use the Fauré, or pasted plate. This type of plate is also used in many farm lighting batteries, but the Plante plate (see page 27) may also be used. The Exide "Chloride Accumulator" cell, Fig. 323 uses a type of positive plate called the "Manchester" positive as described on page 497.