page_310

< previous page | page_310 | next page >

Page 310

| 7. The condition of the cells or batteries may be checked by a hydrometer (Fig. 15-9), which measures the specific gravity of the electrolyte that indicates how much the electrolyte may be diluted. |

| 8. Batteries are charged by sending a direct-current through them in a direction opposite to the discharge current (Fig. 15-11). The dc is usually supplied from rectifiers connected to ac sources. Rates of charging must be such as to prevent gases being given off in lead batteries and overheating in alkaline batteries. |

| STUDY QUESTIONS |

| 1. What is a storage cell? What is a storage battery? How does it store energy? |

| 2. What are the principal component parts of a storage cell? |

| 3. Name two types of storage batteries in general use. What are the differences between them? What are the advantages and disadvantages of each? |

| 4. Describe what takes place in the cells while charging. |

| 5. Describe what takes place in the cells while discharging. |

| 6. What is meant by specific gravity? What is a hydrometer? What is the specific gravity of a fully charged cell? |

| 7. How is the capacity of a storage battery expressed? What does the expression mean? What determines the number of cells in a battery, and how are they connected? |

| 8. How are batteries charged? What indicates the completion of charging? What is meant by an equalizing charge? |

| 9. What are the effects of high and low temperatures on a cell? |

| 10. What factors should be taken into consideration and what precautions observed in the maintenance of storage batteries? |

< previous page | page_310 | next page >