What Are The Effects Of Temperature On Lead-Acid Batteries?

News 2023年4月20日 69

1. Temperature has an impact on battery capacity

At different temperatures, the viscosity of sulfuric acid solution in the battery will be inconsistent, for example, when the battery is below 0℃ temperature, with the decrease of temperature, sulfuric acid solution resistance will continue to increase, directly aggravate the effect of electrode polarization, thereby reducing the capacity of the battery;

2, temperature will affect the charge and discharge

At the beginning, the battery temperature is not high in the repeated discharge and low-voltage constant-voltage charging cycle, because the battery has heat conduction, but if the repeated charging and discharging cycle continues, the electrolyte temperature will rise. When charging at low temperature, the diffusion current density will decrease, while the exchange current density will not decrease much, which will cause the intensification of concentration polarization, thus making the battery charging efficiency low.

3. Temperature has an effect on battery life

If the temperature is too high, it will have a direct impact on the inside of the battery. When the ambient temperature exceeds 45℃, the chemical balance in the battery will be greatly broken, resulting in side reactions. In addition, charging at high temperatures can lead to degradation of battery performance, which reduces battery life.

The ambient temperature not only affects the capacity of the battery, but also affects the life and storage life of the battery in the floating charging state. In the floating charging state, the ambient temperature is particularly important, and the floating charging flow increases with the increase of temperature.

In the process of charging/discharging a battery, the chemical reaction is sometimes too strong/gentle, so that the battery can not work properly.

lead-acid batteries
lead-acid batteries

When the ambient temperature is high:

The high temperature operating environment of battery is the main reason that the actual life of battery cannot reach the designed life. As the temperature of the battery increases, the accepted amount of charging current under constant voltage will increase, and the life of the battery will be shortened due to the increase of the total accumulated energy of overcharging.

At high temperature, the increase of floating charging flow accelerates the accumulation of overcharge, and also accelerates the corrosion rate of grid and the formation and precipitation of gas, thus shortening the battery life. When the battery temperature increases by 10℃, the battery life is shortened by 50% under constant floating charging pressure. High temperature will aggravate internal chemical reactions, resulting in water loss and increased grid corrosion. When the ambient temperature is too high, the discharge capacity of the battery is higher than the actual capacity and the discharge depth also increases. In this case, the storage temperature is too high, resulting in large self-discharge and short storage life.

When the ambient temperature is low:

Battery capacity, charging reception, and charge-discharge cycle life are reduced in a low-temperature environment. The actual discharge capacity of the battery will become smaller. This is why all lead-acid batteries are less than ideal for winter use. In addition, winter temperature can not be too low discharge, otherwise with the decrease of electrolyte density will cause battery icing, causing battery plate expansion, crushing, battery case bulge and other irreparable damage. When the ambient temperature of the battery is low, the discharge performance of the battery is weakened and the capacity of the battery is reduced. Under storage conditions, low temperature, small self-discharge, long storage life.

By adjusting the “floating charging voltage”, the function of ensuring the normal energy conversion of the battery is “temperature compensation”. The reasonable implementation of “temperature compensation” can effectively prolong the service life of the battery and improve the service efficiency of the battery.

lead-acid batteries
lead-acid batteries

How to achieve temperature compensation?

Taking the communication DC switching power supply as an example, to realize temperature compensation, it is necessary that the communication DC switching power supply can monitor the temperature of the battery in real time, and can timely adjust the floating charging voltage of the battery according to the measured temperature. The monitoring unit in the communication DC switching power supply has the ability to monitor the temperature and adjust the floating charging voltage.

For a communication DC switching power supply using a 48 V battery bank, the temperature compensation is usually based on 25 ℃, the floating charging voltage is based on 53.5V, and the adjustment is made at 3 mV/℃ per (2 V) battery.

For example, if the temperature of the 48 V battery is 10 ° C, the floating charge voltage can be calculated as follows:

V floating charge = 53.5V +(10°C-25°C) x (-3 mV) x 24= 54.58V

For the communication power supply, the floating charging voltage of the battery is higher than 53.5V in winter and lower than 53.5V in summer. This is the result of temperature compensation, which is conducive to better management and protection of the battery.

The influence range of temperature compensation is :

Temperature compensation function is to minimize the effect of temperature on the battery, but it is not to say that with the adjustment factor of charging voltage, the battery can be used in any ambient temperature. Because, the temperature compensation function only compensates the chemical reactivity of the battery at different temperatures.

When the ambient temperature is low, the increase of floating charging voltage will also lead to the increase of floating charging flow, acceleration of grid corrosion and a series of problems. When the ambient temperature is high, the floating charge reduction is small, and a series of problems such as insufficient battery charging will be formed. Especially for the station where the ambient temperature changes greatly, it has a great influence on the chemical reaction speed inside the battery.

Therefore, it is necessary to use indoor air conditioning, fresh air system and other equipment to maintain the battery at the best working temperature of 20 ℃-25 ℃, so as to maximize the use of the capacity of the battery, while not damaging the battery.

Caloong adopts advanced production technology and strict quality control system to ensure stable battery quality and reliable performance. Voltage, capacity and seal are 100% checked on line.