Thus, a 100 ampere hour battery, charged from a 110 volt circuit at the rate of ten amperes per hour, would require ten hours to charge, and would consume in that time an amount of electrical energy represented by the product of 110 (voltage) by 10 (amperes) which would give 1,100 watts, or 11/10 kw.
Fig. 1,118.—Diagram illustrating method of charging storage battery of stationary gas engine ignition system; the system is simple to install and will give satisfactory results. Two storage batteries are used, one being charged while the other is operating the sparking coil. Where charging current is available at the point where the batteries are used, the following diagram shows the system of connections, which can be easily followed, A represents the source of charging current and B the bank of lamps (or other resistance, such as an ordinary rheostat) sufficient to cut down the charging voltage to that required by the battery. C and D are two double pole double throw knife switches connected at their hinges to two batteries, E and F, each consisting of a group of cells. G represents the leads to the sparking coil terminals. From the diagram, it will readily be seen that by throwing the switches in opposite directions one battery will be charging while the other battery is discharging to the engine, thus giving a constant source of supply, and insuring that the spare battery will be full and ready for service by the time the other is discharged. The method of determining the necessary resistance for cutting down the line voltage for charging the battery is illustrated by the following example: If a battery require about 3 amperes for charging, how is this current obtained from a 110 volt circuit? Each 16 candle power carbon filament lamp in the lamp bank would give approximately 1/3 ampere with the cells in series in the lamp circuit. Therefore, 3 x 3 or 9 lamps should be used in parallel to give 3 amperes.
Ques. If in charging a battery, one or more of the cells do not boil at the completion of the charge, or fail to show the proper voltage, what should be done?
Ans. The charging must be continued until the cadmium test shows the required voltage, but if the prolonging of the charge be liable to damage the plates in the other cells, the defective cell or cells should be cut out of circuit when the battery discharges and then placed in circuit again when the battery is recharged. If the desired result cannot be attained by this method, the plates which require additional charging may be charged in a separate cell.
Figs. 1,119 and 1,120.—Emergency connections for weak ignition battery. It sometimes occurs through carelessness or neglect, that the storage battery is discharged so low that the engine explosion will not take place, and it is necessary to run somehow or other for a short time. In such cases the following suggestion may be followed: If there be two storage batteries, connect them in series. If there be one storage battery and a set of dry cells, connect the positive terminal of the storage battery to the negative or outside terminal of the dry cell; set and connect to the coil leads as if they were one battery. The above suggestions should only be followed in emergency, for it may injure the coils, and is harmful to the battery.