The Automobile Storage Battery Part 76

Definitions and Descriptions of Terms and Parts ----

Acid. As used in this book refers to sulphuric acid (H2SO4), the active component of the electrolyte, or a mixture of sulphuric acid and water.

Active Material. The active portion of the battery plates; peroxide of lead on the positives and spongy metallic lead on the negatives.

Alloy. As used in battery practice, a h.o.m.ogeneous combination of lead and antimony.

Alternating Current. Electric current which does not flow in one direction only, like direct current, but rapidly reverses its direction or "alternates" in polarity so that it will not charge a battery.

Ampere. The unit of measure of the rate of flow of electric current.

Ampere Hour. The product resulting from multiplication of amperes flowing by time of flow in hours, e.g., a battery supplying 10 amperes for 8 hours gives 80 ampere hours. See note under "Volt?" for more complete explanation of current flow.

Battery. Two or more electrical cells, electrically connected so that combination furnishes current as a unit.

Battery Terminals. Devices attached to the positive post of one end cell and the negative of the other, by means of which the battery is connected to the car circuit.

Bridge (or Rib). Wedge-shaped vertical projection from bottom of rubber jar on which plates rest and by which they are supported.

Buckling. Warping or bending of the battery plates.

Burning. A term used to describe the operation of joining two pieces of lead by melting them at practically the same instant so they may run together as one continuous piece. Usually done with mixture of oxygen and hydrogen or acetylene gases, hydrogen and compressed air, or oxygen and illuminating gas.

Burning Strip. A convenient form of lead, in strips, for filling up the joint in making burned connections.

Cadmium. A metal used in about the shape of a pencil for obtaining voltage of positive or negative plates. It is dipped in the electrolyte but not allowed to come in contact with plates.

Capacity. The number of ampere hours a battery can supply at a given rate of current flow after being fully charged, e.g., a battery may be capable of supplying 10 amperes of current for 8 hours before it is exhausted. Its capacity is 80 ampere hours at the 8 hours rate of current flow. It is necessary to state the rate of flow, since same battery if discharged at 20 amperes would not last for 4 hours but for a shorter period, say 3 hours. Hence, its capacity at the 3 hour rate would be 3x2O=60 ampere hours.

Case. The containing box which holds the battery cells.

Cell. The battery unit, consisting of an element complete with electrolyte, in its jar with cover.

Charge. Pa.s.sing direct current through a battery in the direction opposite to that of discharge, in order to put back the energy used on discharge.

Charge Rate. The proper rate of current to use in charging a battery from an outside source. It is expressed in amperes and varies for different sized cells.

Corrosion. The attack of metal parts by acid from the electrolyte; it is the result of lack of cleanliness.

Cover. The rubber cover which closes each individual cell; it is f.l.a.n.g.ed for sealing compound to insure an effective seal.

Cycle. One charge and discharge.

Density. Specific gravity.

Developing. The first cycle or cycles of a new or rebuilt battery to bring about proper electrochemical conditions to give rated capacity.

Diffusion. Pertaining to movement of acid within the pores of plates.

(See Equalization.)

Discharge. The flow of current from a battery through a circuit, opposite of "charge."

Dry. Term frequently applied to cell containing insufficient electrolyte. Also applied to certain conditions of s.h.i.+pment of batteries.

Electrolyte. The conducting fluid of electro-chemical devices; for lead-acid storage batteries it consists of about two parts of water to one of chemically pure sulphuric acid, by weight.

Element. Positive group, negative group and separators.

Equalization. The result of circulation and diffusion within the cell which accompanies charge and discharge. Difference in capacity at various rates is caused by the time required for this feature.

Equalizing. Term used to describe the making uniform of varying specific gravities in different cells of the same battery, by adding or removing water or electrolyte.

Evaporation. Loss of water from electrolyte from heat or charging.

Filling Plug. The plug which fits in and closes the orifice of the filling tube in the cell cover.

Finis.h.i.+ng Rate. The current in amperes at which a battery may be charged for twenty-four hours or more. Also the charging rate used near the end of a charge when cells begin to gas.

Flooding. Overflowing through the filling tube.

Forming. Electro-chemical process of making pasted grid or other plate, types into storage battery plates. (Often confused with Developing.)

Foreign Material. Objectionable substances.

Freshening Charge. A charge given to a battery which has been standing idle, to keep it fully charged.

Ga.s.sing. The giving off of oxygen gas at positive plates and hydrogen at negatives, which begins when charge is something more than half completed-depending on the rate.

Generator System. An equipment including a generator for automatically recharging the battery, in contradistinction to a straight storage system where the battery has to be removed to be recharged.

Gravity. A contraction of the term "specific gravity," which means the density compared to water as a standard.

Grid. The metal framework of a plate, supporting the active material and provided with a lug for conducting the current and for attachment to the strap.

Group. A set of plates, either positive or negative, joined to a strap. Groups do not include separators.

Hold-Down. Device for keeping separators from floating or working up.

Hold-Down Clips. Brackets for the attachment of bolts for holding the battery securely in position on the car.

Hydrogen Flame. A very hot and clean flame of hydrogen gas and oxygen, acetylene, or compressed air used for making burned connections.

Hydrogen Generator. An apparatus for generating hydrogen gas for lead burning.

Hydrometer. An instrument for measuring the specific gravity of the electrolyte.

Hydrometer Syringe. A gla.s.s barrel enclosing a hydrometer and provided with a rubber bulb for drawing up electrolyte.