JPH01137567A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To prevent the quick performance reduction of an end cell in which the electrolyte temperature is liable to rise and improve the life performance at a high temperature by setting the electrolyte specific gravity of the cell at one end lower than that of other cells. CONSTITUTION:The electrolyte specific gravity of a cell at least at one end of a mono-block type lead storage battery 1 is set lower than that of the other cells by the range of 0.010-0.030. When the electrolyte specific gravity of the end cell 1 in which the electrolyte temperature is liable to rise is set low, the deterioration of a negative electrode active material can be suppressed. The progress of its deterioration is improved at least to the same degree as the other cells, and the life performance of the battery is improved. When the battery is to be actually mounted on an automobile, it is considered that the sixth cell may be arranged near an engine 2, the electrolyte specific gravity of both the first cell and the sixth cell is preferably lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improvement of a monoblock lead acid battery, and provides a lead acid battery with excellent high temperature resistance.

Conventional technology It is said that the modern era is an age of light, thin, short and small size, and lead-acid batteries are no exception; there is a strong demand for smaller and lighter batteries, and diligent efforts are being made to make them lighter and smaller. on the other hand,
Cars, which are the main use for lead-acid batteries, have similarly become smaller and lighter, and with the demand for spacious and comfortable living spaces, the interior of the engine compartment, where lead-acid batteries are affected, has become more compact. It has become to.

Problems that the invention aims to solve As a result, the engine room becomes hot, and lead-acid batteries are placed closer to the engine than before, and lead-acid batteries tend to be exposed to higher temperatures than before. It has become to.

As a result of surveying several batteries that were actually installed in automobiles and had reached the end of their service life, we found that in lead-acid batteries with 6-cell blocks and 7-cell blocks, as shown in Figure 1, cells closer to the engine in the engine room, in other words, It was found that the cell, which is prone to high temperatures, deteriorated significantly and this cell deterioration led to the end of its service life. When this deterioration was further investigated, focusing on the negative electrode plate, it was found that the decrease in the surface area of the active material was greater than in other cells.

Means for Solving the Problems The present invention obviates the above-mentioned drawbacks by reducing the specific gravity of the electrolyte in at least one of the cells of the E-Nobron type 9 lead-acid battery to 0.030 to 0.030 compared to the remaining cells. It is characterized by being low in the range.

By lowering the specific gravity of the electrolyte in the end cells where the working electrolyte tends to reach high temperatures, it is possible to suppress the decrease in the surface area of the negative electrode active material.
The progress of deterioration is improved to at least the same extent as other cells, and the battery life performance is improved.

EXAMPLE An example of the lead-acid battery of the present invention will be described below. 1st
The figure is an explanatory diagram showing the positional relationship between a lead-acid battery and a heat source.
1 is a lead acid battery, and 2 is a heat source.

The lead-acid battery 1 consists of six cells, from the first cell closest to the heat source to the sixth cell farthest. Second! Adjust the specific gravity of the electrolyte from cell to cell 6 to 1.280 (conversion value at 20℃, the same applies hereinafter), and that of cell 1 as shown in Table 1, and place it in the position shown in Figure 1 relative to the heat source. The battery was placed in the
A truncated discharge was performed for 30 seconds at 3° C.), and the voltage change over 30 seconds was examined.

Discharge 25AX 4 minutes charge 14.8V (31 large 25A>

As is clear from FIG. 2, the products B, C, and D of the present invention were able to significantly improve the life performance compared to the conventional product F. Electric it with electrolyte specific gravity lowered by 0.005! l! In battery E, an improvement in life performance was observed, but it was small, while in battery A, in which the electrolyte specific gravity was lowered by 0.035, the improvement in life performance was small.Although not shown here, the initial improvement in life performance There was a significant decrease in discharge performance.

In addition, in this example, the case where only the first cell has a lower electrolyte specific gravity has been described, but when it is actually installed in a car, the sixth cell may be placed near the engine, so the first cell It is considered that it is better to lower the electrolyte specific gravity of both the cell and the sixth cell.

Effects of the Invention As described above, according to the present invention, it is possible to prevent sudden performance deterioration of the cells at the ends where the electrolyte temperature tends to rise, and to improve the life performance under high temperatures, which is of great industrial value.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the positional relationship between the lead-N battery and the heat generation source, and Figure 2 is 24OA (43℃) after every 500 or more charge/discharge cycles.
It is a figure showing the change in voltage for 30 seconds of discharge. 1...Lead-acid battery, 2...Heating source, 2nd battery, 2nd battery, 2nd battery.

Claims (1)

[Claims] 1. In monoblock lead-acid batteries, the electrolyte specific gravity of at least one end cell is at least 0 compared to other cells.
．． 1. A lead-acid battery characterized in that the battery has a low temperature in a range of 0.010 or more and 0.030 or less.