Zinc-carbon batteries characteristics

Lead is sometimes still used in both battery systems. In zinc-carbon batteries it is employed chiefly as an alloying addition to improve the forming characteristics of the zinc can, and additionally acts as a corrosion inhibitor. In alkaline-manganese it has found use as a plating alloy on the brass nail to reduce gassing. In zinc-carbon cells, the lead content is in the order of 0.02% and in those alkaline-manganese batteries where lead is still used, the addition is at a level of a few parts per million. 

FIGURE 3.15 Discharge characteristics of a 9-volt battery subjected to a 100 ms pulse (smoke detector pulse tests) (a) zinc-carbon battery (b) and (c) zinc/alkaline/ manganese dioxide battery. 

Zinc-Carbon Battery. The Leclanche or zinc-carbon dry cell battery has existed for over 100 years and had been the most widely used of all the dry cell batteries because of its low cost, relatively good performance, and ready availability. Cells and batteries of many sizes and characteristics have been manufactured to meet the requirements of a wide variety of applications. Significant improvements in capacity and shelf life were made with this battery system in the period between 1945 and 1965 through the use of new materials (such as beneficiated manganese dioxide and zinc chloride electrolyte) and cell designs (such as the paper-lined cell). The low cost of the Leclanchd battery is a major attraction, but it has lost considerable market share, except in the developing countries, because of the newer primary batteries with superior performance characteristics. 

Carbon-Zinc Batteries, Tabie 1 Carbon-zinc system energy characteristics... 

The effect of temperature on the available capacity of zinc-carbon (Leclanch6 and zinc-chloride systems) batteries is shown graphically in Fig. 8.28 for both general-purpose (ammonium chloride electrolyte) and heavy-duty (zinc-chloride electrolyte) batteries. At — 20°C typical zinc-chloride electrolytes (25% to 30% zinc-chloride by weight) turn to slush. Below -25°C ice formation is likely. Under these conditions, it is not surprising that performance is dramatically reduced. These data represent performance at flashUght-type current drains (300 mA for a D-size cell). A lower current drain would result in a higher capacity than shown. Additional characteristics of this D-size battery at various temperatures are listed in Table 8.7. 

Table 1.12 Characteristics of Carbon-Zinc and Alkaline Batteries...

Carbon-Zinc Primary Low-Power Batteries and Their Characteristics... 

---