Testing Dry Batteries

Radio Record, Volume II, Issue 53, 19 July 1929, Page 37

Testing Dry Batteries

jt is frequently stated that a battery ' should not be allowed to-drop more than one quarter of its rate of voltage -that is to say, a battery registering 45 yolts.should be discarded at 38 volts. At this voltage artificial static appears, A voltmeter should be kept by every radio enthusiast who requires the best from his set, and the batteries ta be constantly tested, but they must be tested under working conditions. Dry batteries are composed of a large number of Leelanche cells, which have the power of recuperating to a great extent, when not working. This means that if a battery which has been working: is left for several hours, the yoltage will rise, but during the next ten minutes or so of operation, it will rapidly drop, so that the only true test of battery yoltage ean be made after the set has been working some time. a The battery may be tested either by placing the tester direetly across the battery or by testing the voltages on each valve, Place the nositive of the volt. meter on the B. terminal of the transformer adjacent toa the valve to be tested, and the negative on B minus. The reading should be approximately that required by the valve, slightly higher, if anything, to allow for the drep across the trans-

former. This should be compared with the reading, directly across the battery, as ‘it. will reveal any defects in batterywinding.