Ques. Describe the electrolyte generally used.
Ans. It consists of a weak solution of sulphuric acid which permits ready conduction of the current from the primary battery, the greater the proportion of acid within certain limits, the smaller the resistance offered.
Fig. 1,054.—Elements of 6 volt 40 ampere hour "Aplco" portable (3 cell) storage battery. The grids are made from an alloy of lead and antimony; hard lead straps which are burned together, are used for joining the plates. Specially treated separators are used.
Ques. What is the effect of the current passing through the electrolyte?
Ans. It decomposes the water into oxygen and hydrogen; this is indicated by the formation of bubbles upon the exposed surfaces of both plates, these bubbles being formed by oxygen gas on the plate connected to the positive pole of the primary battery, and hydrogen on the plate connected to the negative pole.
Because, however, the oxygen is unable to attack either platinum or silver under such conditions, the capacity of such a device to act as an electrical accumulator is practically limited to the point at which both plates are covered with bubbles. After this point the gases will begin to escape into the atmosphere.
Ques. What is the prime condition for operation of a storage battery?
Ans. The resistance of the electrolyte should be as low as possible in order that the current may pass freely and with full effect between the electrodes. If the resistance of the electrolyte be too small, the intensity of the current will cause the water to boil rather than to occasion the electrolytic effects noted above.