CR1220 battery

What should be paid attention to during the discharge process of CR1220 battery

Valve-regulated CR1220 battery are also called maintenance-free batteries. Their basic characteristics are that they do not need to be maintained by adding acid or water during use. The battery is a sealed structure, will not leak acid, and will not discharge acid mist. A one-way exhaust valve (also called a safety valve) is installed on the battery cover. Here are some things to pay attention to during the discharge process of CR1220 battery

1. In order to fully charge the battery, the battery pack should be charged in advance before the discharge point. Generally, it is charged at 2.35V/cell for 12 hours and left to stand for 12-24 hours.

2. It is necessary to check the tightening status of all screws, as well as the total floating charge voltage of the battery pack, the floating charge voltage of the cell, the load current, the ambient temperature, and other setting parameters of the rectifier (or switching power supply).

3. Combined with the actual situation of the base station/exchange, disconnect the connection between the battery pack and the switching power supply, confirm that the dummy load is in the no-load state, and correctly connect the dummy load to the positive and negative poles of the battery pack. After 15 minutes, record the open circuit voltage of the battery.

4. Determine the discharge rate of the battery pack according to the situation. Generally, discharge at a 3-hour rate or a 10-hour rate (the discharge current at a 3-hour rate is 0.25C10, and the discharge current at a 10-hour rate is 0.10 C10). Select a matching load on the dummy load to discharge the battery pack.

5. During the discharge process, considering that the current meter display on the dummy load is not accurate enough, a clamp ammeter is required to detect the discharge current. According to the actual display of the clamp meter, adjust the dummy load to make the discharge current of the battery pack reach the required discharge current. After discharging for about 5 minutes, start recording the total voltage, single cell voltage, discharge current, ambient temperature, and temperature of the connecting strip of the battery pack.

6. If you choose to discharge at a 10-hour rate, measure the total discharge voltage, single cell voltage, discharge current, etc. of the battery every 1 hour (every 30 minutes for 3-hour rate discharge): the frequency of measurement should be increased in the later stage of discharge. The 10-hour rate is measured every 30 minutes after 9 hours; the 3-hour rate is measured every 15 minutes after 2 hours. During the discharge process, the ambient temperature, the temperature of the battery cells and the connecting strips should be monitored to see if there are any abnormal conditions, and the battery cell with the lowest discharge voltage in the battery pack.

7. For newly installed battery packs, the discharge end condition is that the battery pack discharge capacity reaches the rated capacity requirement or one of the cells in the battery pack reaches 1.80V, while for battery packs that have been used online, the discharge ends when the total voltage reaches 43.2V (48V battery system).

8. For the situation during the discharge process, if the capacity discharged by the battery pack does not reach the specified rated capacity after calculation at the end of the discharge, there may be a problem with the factory capacity of the battery pack, and the relevant manufacturer should be contacted in time for processing.

9. After the discharge is completed, let the dummy load unloaded first, then disconnect the battery pack from the dummy load, and connect the battery to the switching power supply. At this time, it should be noted that the voltage difference between the discharged battery pack and the rectifier is large, and sparks may occur during connection. It is best to first lower the floating charge voltage value of the switching power supply so that the floating charge voltage value of the switching power supply is as close to the open circuit voltage of the battery pack as possible to reduce sparks.

10. If the discharge is normal, observe and record the start of charging. If the discharge is abnormal, monitor the charging of the battery pack to ensure normal charging of the battery.

11. Tools: dummy load, connecting cable, loading and unloading tools, clamp ammeter, multimeter, etc.

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