When the battery is charged, the internal gas recombination itself is an exothermic reaction, which increases the temperature of the battery, increases the floating charge current, and increases the gas evolution, which promotes the battery temperature to rise higher. The battery itself is "lean" and is tightly assembled. It is difficult to dissipate heat. If the heat is not removed in time, it will cause thermal runaway. If the voltage at the end of floating charge is too high and the ambient temperature around the battery rises, the thermal runaway of the battery will be aggravated.
Every time the temperature rises by 1°C, the battery voltage drops by about 3mV/cell, which causes the float charge current to rise and the temperature further rises. Temperatures higher than 50°C will deform the battery compartment. When the temperature is lower than -40℃, the valve-regulated lead-acid battery can still work normally, but the battery capacity will be reduced.
Valve-regulated lead-acid batteries have high temperature requirements due to structural problems. Everyone has noticed this. For this reason, temperature compensation measures are considered when designing charging equipment, but the selection of temperature sampling points is very important, and it is directly related to The effect of compensation. There are three temperature sampling points, namely, the air temperature near the battery, the surface temperature of the battery shell, and the temperature of the electrolyte inside the battery. The first place is the easiest, basically all use this method, but this method is very inaccurate, because the temperature of the battery rises for some reason, but the rise of the battery temperature will hardly cause the temperature of the air near the battery to rise, so This kind of compensation measure is basically useless; the third place can best reflect the actual situation of the battery, but it is more difficult to achieve; the second place is the most practical and easier to implement. Some companies design temperature compensation units based on the second sampling.