Starter batteries

1 Volume energy or mass energy the ratio of the energy stored to the volume or mass (see section 2.4.9). 

2 Here we choose to work with receiver convention, meaning that the current entering at the positive terminal of the battery, i.e. the current that recharges the battery, is counted positively. 

3 For motorcycles, we find 6 V and 12 V batteries. The capacities range from a few Ah to over 30 Ah. 

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The demand for electrically operated tools or devices that can be handled independently of stationary power sources led to a variety of different battery systems which are chosen depending on the field of application. In the case of rare usage, e.g., for household electric torches or for long-term applications with low current consumption, such as watches or heart pacemakers, primary cells (zinc-carbon, alkaline-manganese or lithium-iodide cells) are chosen. For many applications such as starter batteries in cars, only rechargeable battery systems, e.g., lead accumulators, are reasonable with regard to costs and the environment. 

The historical development of the separator and of the lead-acid storage battery are inseparably tied together. When referring to lead-acid batteries today one primarily thinks of starter batteries or forklift traction batteries, but the original applications were quite different. 

The microporous polyethylene pocket has succeeded worldwide more than 70 percent of all starter batteries use this form of separation. Whereas in the USA and Western Europe the transition is essentially complete, a similar development in the Asia-Pacific area and Latin America, and in the medium term also in Russia and China, is expected [3],... 

In the second half of the 1960s, at the same time but independently, three basically different plastic separators were developed. One was the polyethylene separator [16] already referred to in starter batteries, used only rarely in stationary batteries, but successful in traction batteries. The others were the microporous phenolic resin separator (DARAK) [18] and a microporous PVC separator [19], both of which became accepted as the standard separation for stationary batteries. They distinguish themselves by high porosity (about 70 percent) and thus very low electrical resistance and very low acid displacement, both important criteria for stationary batteries. 

Filled polyethylene separators are the only pocket material that has been able to meet all requirements of a starter battery reliably [39-48]. It is flexible and weldable into three-sided closed pockets, making the previously usual mud room at the bottom... 

Figure 10. Starter battery with pocketed plates )...

The term leaf separator characterizes the customary stiff version of a starter battery separator that can be inserted individually between the electrodes on automatic stackers, in contrast to pocket separators. This processing requires considerably higher bending stiffness than for pocket separators, calling for thicker backwebs, typically 0.4-0.6 mm (Fig. 18 and 19). 

The production process is comparatively simple, even though — of course — the respective know-how is also decisive. The equipment for the production of sintered PVC separators is suitable in size and production capacity to be operated on its own by individual, medium-sized, starter battery plants, in contrast to the far larger units required for the production of polyethylene pocket material. 

Typical pore size distributions result in mean pore diameters of around 15 //m. Even long and intensive efforts did not succeed in decreasing this value decisively in order to enable production of micropo-rous pocketing material resistant to penetration [65, 66], In practice PVC separators prove themselves in starter batteries in climatically warmer areas, where the battery life is however noticeably reduced because of increased corrosion rates at elevated temperature and vibration due to the road condition. The failure modes are similar for all leaf separator versions shedding of positive active mass fills the mud room at the bottom of the container and leads to bottom shorts there, unless — which is the normal case — the grids of the positive electrodes are totally corroded beforehand. 

In many countries starter batteries are almost 100 percent recycled PVC separators can cause some problems here [67]. A prior separation of PVC from other battery components, which is quite tedious, would be desirable, because a PVC content decreases the recycling purity of the container polypropylene and makes further processing of this plastic more difficult. Also, any chlorine compounds liberated can form environmentally hazardous products with other substances the usual remedy is to install costly filter stations, with the residues representing possibly toxic wastes requiring special disposal methods. 

The closest relative to the wood veneer surprisingly has retained some of its properties, which differentiate these separators from pure synthetic ones primarily, a positive effect in reducing the water loss in starter batteries [39, 70-72], This impact tends to decrease as the antimony content in the alloys is lowered, but it still represents an advantage over other leaf separators, unless a microporous pocket is required by the alloy anyway. 

The development of the starter battery in Japan has taken an independent course (see Sec. 9.2.1.2), visibly expressed by the separator s thick glass mat and its lack of spacing ribs (cf. Fig. 19). The cellulosic backweb impregnated with phenolic resin, generally in use until around 1980 and largely identical to the separator of the same type already mentioned has been completely replaced by thin ( 0.3 mm) fleece materials made of organic fibers. 

Even though this separation system has not yet entered the starter battery field, it should be discussed here as a possible option for the future. 

The individual starter battery separator systems have been described here they are evaluated comparatively. There are no standards for evaluating separators Therefore the comparison will be concentrated primarily on the effects on the performance of the starter battery, with other decisive criteria such as cost structure and effects on productivity indicated. 

Cold crank performance, battery life expectancy, and freedom from maintenance are generally co-affected by the separators, whereas ampere-hour capacity remains largely unaffected at a given separator thickness. The properties of the different leaf and pocket separators are compared in Table 10. These typical separator properties (lines 1-4) are reflected in the electrical results of battery tests (lines 5-8). The data presented here are based on the 12 V starter battery standard DIN 43 539-02 tests based on other standards lead to similar results. 

The life expectancy of a starter battery, according to DIN 43 539-02, is not affected by the separator. Experience has... 

Table 10. Comparative evaluation of starter battery separators...

Surprisingly the water consumption of a starter battery, provided it contains anti-monial alloys, is affected by the separator. Some cellulosic separators as well as specially developed polyethylene separators (e.g., DARAMIC V [76]) are able to decrease the water consumption significantly. The electrochemical processes involved are rather complex and a detailed description is beyond the scope of this chapter. Briefly, the basic principle behind the reduction of water loss by separators is their continuous release of specific organic molecules, e.g., aromatic aldehydes, which... 

The above comparative evaluation of starter battery separators refers to moderate ambient temperatures the standard battery tests arc performed at 40 or 50 °C. What happens, however, on going to significantly higher temperatures, such as 60 or 75 °C This question cannot be answered without considering the alloys used batteries with antimonial alloys show a water consumption that rises steeply with increasing temperature [40], leaving as the only possibilities for such applications either the hybrid construction, i.c., positive electrode with low-antimony alloy, negative electrode lead-calcium, or even both... 

Without any doubt the microporous polyethylene pocket will meet all requirements of modern starter batteries for the foreseeable future. Whether and to what extent other constructions, such as valve-regulated lead-acid batteries, other battery systems, or even supercapacitors, will find acceptance, depends — besides the technical aspects — on the emphasis which is placed on the ecological or economical factors. 

It can be stated generally that requirements for traction battery separators in respect to mechanical properties and chemical stability are considerably higher than for starter battery separators. This is due to the fact that a forklift battery is typically... 

Sintered PVC separators for open stationary batteries are produced in the same way as the corresponding starter battery version (Sec. 9.2.2.2). Their brittleness and thus difficult processability are disadvantages, as is their relatively low porosity the concerns about release of chloride ions and subsequent increased corrosion are to be considered here as well. On the other hand,... 

Mn02 in KOH 118 standard profiles, separators 262 starter battery separators 252 f, 258 f starter light ignition (SLI) batteries 2 stationary battery separators 254... 

Example with nigrosine paste and silver electrodes, a storage of 1.5 mAh/cm3 and, at a mean voltage of 0.9 V with a discharge time of about 11 min, a volumetric storage capacity of 1.3 mWh/cm3 were measured. The corresponding capacity of a lead starter battery is 11 mAh/cm3 or 15 mWh/cm3. 

Since 1803, when Ritter invented the voltaic pile, rechargeable batteries have been known to exist [5]. The big breakthrough came in 1859, when Plante introduced the lead-acid battery [6]. Until today, this kind of secondary battery has been the most well-known electrochemical device. It is omnipresent in every car as a starter battery and also plays an important role in stationary energy storage (e.g. for uninterruptable power supplies). 

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