Lead: (key words: communication power supply UPS backup power supply mobile phone battery for mobile communications) today has become the most commonly used tools, wireless communications network throughout every corner, these are all through the towers transit connect to microwave signals, to people's life and work bring very big convenient, people also more and more inseparable from it. If the communication base station outages due to different reasons, it will bring great inconvenience or cause great loss and influence. In order to ensure the power supply of the base station, UPS power supply is often required.

1. Communication base station backup power requirements:

The early backup power supply mostly used lead-acid battery as the backup power supply. Due to lead acid is not environmental protection, and low energy ratio, large volume, short life and other shortcomings, now the new or upgraded base station gradually began to use lithium ion battery as the base station backup power supply system. Based on the above problems, our customer requires lithium battery as the main power supply. The backup power supply system can support the whole launch system to work for more than two hours after power failure, and can meet the requirements of long-term operation of the system in the field.

According to the power consumption and conversion efficiency of the whole transmission system, we calculate that the battery pack needs 48V 65Ah to meet the customer's working time requirements. Due to the high voltage of the whole battery group, the overall battery capacity is relatively large, the environment temperature is relatively high, and in order to ensure the stability of the whole system, in terms of lithium battery cell, we use Japan imported lithium battery cell, the overall consistency of the cell is high, each cell is built-in multiple protection, including explosion-proof valve, PTC and so on.

The PCM protection system unit of the power supply system includes: 1. 2 the whole battery temperature protection, over current protection, short circuit protection; 3. Balance system between single series batteries;

Battery power detection includes detection system and display system. The detection adopts the method of current and voltage calculation, the display and detection accuracy is very high, with THE LCD screen dynamic intuitive detection of the whole battery charge and discharge state.

Second, communication base station backup power design scheme:

1) Battery pack design parameters: We calculated the voltage and capacity of the battery as 12.8V/150Ah according to the UPS conversion efficiency and matching voltage, and selected the lithium iron phosphate battery scheme ICR26650/3.2V/3000mAh.

2) Protection plate (PCM) design parameters: single section overcharge, overdischarge, temperature, overcurrent, short circuit protection, voltage balance and so on. Specific protection parameters are as follows:

1, single overcharge protection voltage: 3.75±0.025V

2, single overcharge recovery voltage: 3.6±0.050V

3, single section overdischarge protection voltage: 2.00±0.10V

4, single over-discharge recovery voltage: 2.4±0.10V

5, combined battery overcurrent protection value (10ms) : 60A

6, charging balance current: 50±10mA

7, charging balance voltage: 3.65±25mV

8, battery temperature protection range (recoverable) : -20~60 degrees

9, the finished battery also has short circuit protection

3) battery monitoring system (PCM) design features: adopts intelligent dedicated chip, with LCD display, can use in real time through the buttons to set the display parameters, display part contains: the battery percentage of current capacity, the current capacity, the current battery voltage, charging current, discharge current, discharge time, remaining battery charged state of (SOC).



4) Overall structure design requirements of the battery: as the base station is widely distributed and placed in the field, besides the insulation of the battery, moisture resistance and aging resistance should also be considered, so the glass fiber board is adopted as the main body of the shell structure. Due to the large number of battery cell combinations, isolation and heat dissipation problems need to be considered. We adopt the engineering plastic bracket for battery as the main body of lithium battery pack fixation and isolation.

5) Secondary protection: the whole battery group is equipped with abnormal overcurrent short circuit protection fuse to prevent excessive current caused by abnormal battery and protection plate failure. If the PCM system is abnormal and generates excessive current, the fuse will cut off the output loop of the battery string and cannot be recovered.

6) Lithium battery cell: imported from Japan, 18650 lithium battery cell / 18650/2500mah /3.7V, the cell has good safety and consistency, so as to ensure the reliability of the whole battery pack.