CTECHi Technology Co. Ltd

LiFePO4batteries and lead-acid batteries are used in base stations, mainly consideringthat different discharge rates have less influence on the discharge capacity ofsuch batteries, and that they can withstand a wide range of ambienttemperatures. The following will analyze the battery capacity selection basedon the power consumption and backup time of the base station.

BASESTATIONS CAN BE DIVIDED INTO THE FOLLOWING TWO TYPES:

(1)Macro base station and indoor distributed source station

Thepower of GSM macro base station can be calculated according to 3.5A / carrierfrequency, and it is divided into township (4/4/4) 46A, urban area (12/12/12)130A, and extremely dense urban area (15/15/15) 160A.

Thepower of TD macro base station is divided into single-band station (including 1BBU and 3 RRU) 1200W25A, dual-band station (1 BBU and 6 RRU) 2100W44A, of which1 BBU300W and 1 RRU300W.

Thepower of indoor distributed source stations is divided into single-bandstations (including 1 BBU and 5 RRU) 1000W21A, dual-band stations (1 BBU and 10RRU) 1400W29A, and tri-band stations (1 BBU and 15 RRU)

2100W44A,including one BBU600W and one RRUSOW.

Thebattery backup time for macro base stations and indoor distributed sourcestations is: 3h in urban areas, 5h in towns, and 7h in mountain areas.

(2)The indoor distributed RRU can include one or more RRUs. A single RRU consumes80W1.67A of power and requires 4 hours of battery backup time.

Accordingto calculations, the configuration of lead-acid batteries is as follows:

Wireless device configuration	Installation Location	Current (A)	Time (h)	Capacity (Ah)	Voltage (V)	Lead acid information
12 carrier frequencies(46A)	Town	50	5	423.91	48	500Ah*1 / 200Ah*2
12 carrier frequencies(46A)	Mountain	50	7	554.84	48	300Ah*2
36 carrier frequencies(130A)	Urban area	134	3	796.95	48	500Ah*2
36 carrier frequencies(130A)	Town	134	5	1133.71	48	600Ah*2
45 carrier frequencies(160A)	Urban area	164	3	975.15	48	500Ah*2
TD macro base station or source	Urban area	48	3	286.11	48	150Ah*2
TD macro base station or source	Town	48	5	407.01	48	200Ah*2
RRU*1	Urban area	1.66	5	14.08	48	50Ah*1
RRU*3	Urban area	5	5	42.25	48	50Ah*1

Limitedby the type of LiFePO4 battery products, the current mature ones are 50Ah,100Ah, 150Ah,

200Ah.Take 48V / 50A communication load for 5 hours as an example to conductselection and investment comparison.

Theconstant current discharge data of LiFePO4 battery is shown in the followingtable:

LiFePO4 Battery	Constant current discharge    Discharge time(h) and termination voltage(2.6V)
300Ah	Time(h)	11	4.30	1.95	1.05	0.33
	Current(A)	30	75	165	300	900
	Capacity(Ah)	330	323	321	316	296
	Discharge rate	0.10C	0.25C	0.55C	1C	3C
200Ah	Time(h)	12.65	4.94	2.18	1.15	0.33
	Current(A)	20	50	110	200	600

Theuse of LiFePO4 batteries in base stations has the following advantages:

1.Small capacity: The discharge capacity of the LiFePO4 battery is not as obviousas that of the lead-acid battery due to different discharge rates. Therefore, abattery with a smaller capacity can be selected to meet the power demand of thesame communication load.

2.Good high temperature performance: The existing base station air conditioner isset to 28 ° C. If it is raised to 35 ° C, a lead-acid battery needs to beequipped with a separate insulation box. Otherwise, every 10 ° C increase intemperature will reduce the battery life by half. The LiFePO4 battery canwithstand high temperatures of 55 ° C, and its life is not affected. Thetemperature setting value of the base station can be directly increased toachieve energy saving and emission reduction.

3.Small size and light weight: 3.2V / 200Ah LiFePO4 battery size (length * width* height) 360 * 55 * 250, weight 8.1kg; 3.2V / 300Ah LiFePO4 battery size(length * width * height) 360 * 55 * 306, weight

9.6kg;2V / 300Ah lead-acid battery size (length * width * height) 124 * 181 * 365,weight 19kg.

One48V / 200Ah LiFePO4 battery pack and one 48V / 300Ah lead-acid battery packhave the same installation mode. The former covers 59% of the area and theformer weighs 28% of the latter. If it is considered that under the sameload-bearing conditions of the computer room, the LiFePO4 battery can beinstalled in a double-layer dual-row, and the lead-acid battery needs to beinstalled in a single-layer dual-row, the former covers an area of 29% of thelatter. The same set of 48V / 300Ah LiFePO4 battery and lead-acid battery pack,under the same installation method, the former covers an area of 59% of thelatter, and the former weighs 34% of the latter.

4.Long cycle life: The LiFePO4 battery has more cycle life, and is especiallysuitable for use in four types of mains base stations with repeated poweroutages.

5.Investment is flat: the price of a group of 48V / 300Ah lead-acid batteries isabout 8640 yuan (collection price: 1.2 yuan)

/2V.Ah),a group of 48V / 200Ah LiFePO4 battery price is about 25600 yuan (market price:8 yuan

/3.2V.Ah),the price of a group of battery insulation boxes is about 100 million yuan, andthe price of a group of LiFePO4 batteries (without insulation boxes) is 1.37times that of a group of lead-acid batteries (including insulation boxes). Whenthe price of LiFePO4 battery drops to 6 yuan / 3.2V.Ah, the price of a group ofLiFePO4 battery (without insulation box) is 19,200 yuan, and the cost of thetwo is basically the same. In addition, the reduction of the area and weight ofthe equipment room can reduce the construction cost of the equipment room, thecycle life of the LiFePO4 battery is better, the battery replacement cycle canbe extended, and the high-temperature performance can save air-conditioningpower.

6.High resistance to environmental temperature: When the lead-acid battery isused in outdoor stations, it needs to be installed in a thermal insulationcabinet. In areas with particularly harsh climate conditions, it also needs tobe buried in the frozen soil layer, which brings great damage to installationand maintenance. inconvenient. The LiFePO4 battery is suitable for high ambienttemperature, charging ambient temperature is 0 ° C ~ 55 ° C, and dischargeambient temperature is -20 ° C ~ 60 ° C. It is suitable for outdoor stationswithout machine rooms, no air conditioning, and ambient temperature above zero.