Power source of traditional emergency fire pump works for emergent fire protection supported by lead-acid battery or diesel engine. Because lead-acid battery has low energy density, heavy weight, low rate discharging efficiency and non-environmental performance, and diesel engine has loud noise and non-environmental performance, neither lead-acid battery nor diesel engine can meet the requirements of modern portable emergency power source. On the contrary, lithium ion battery has advantages of high specific energy, light weight, small size, long cycle life, good security, high rate, etc. It has been the first choice to replace lead-acid and diesel in many emergency power source area.
48V/6Ah power battery of fire pump is a lithium ion battery using ternary as anode material with good safety performance. Its main function is providing power source for fire pump. The battery of fire pump has advantages of high rate discharging, large discharging current, long charging and discharging cycle life, low discharging rate, long cycle life, good deep-discharging capability, high charging efficiency, seldom or no maintenance demand and IV ESD.
1）Design requirement of lithium ion battery type: 18650-13S3P/6Ah/48V
2）Design requirements of electric circuit:
• Over-charged protection voltage of single battery: 4.3±0.25V
• Over-charged recovery voltage of single battery: 4.15±0.50V
• Over-discharged protection voltage of single battery: 2.80±0.08V
• Over-discharged recovery voltage of single battery: 3.00±0.10V
• Over-discharge cut-off current of battery pack: 120A
• Continuous discharging current: Less than or equal to 60A
• Temperature protective value of battery (restorable): 70±5℃
• The finished product has protective function of short circuit and reverse-charging.
3）Design requirement of battery cycle life: 500~1000 times (national charging and discharging standard)
4）Design requirement of battery dimension: 310*210*120mm PVC package
II. Power battery design scheme of emergency fire pump
1）Guard plate (PCM): It is protective circuit of rechargeable lithium ion battery pack. Because of the chemical characteristics of lithium ion battery, it needs protective function of overcharging, over-discharging, short circuit, overcurrent, over temperature, etc. so as to avoid combustion, explosion, etc.
2）Protection IC: It is the chip has main protective function in the design scheme. The chip monitors the cell on the functions of overcharging, over-discharging, overcurrent, short circuit, etc. at any time, which helps the battery works under safe, stable and efficient circumstance.
3）Temperature switch: It is designed for temperature protection. When the battery is heated up to 75℃ due to any issues, the temperature switch opens to protect the battery. When the temperature is decreasing, it will recover automatically.
4）18650 lithium ion battery/18650/2000mAh/3.7V 10C (SANYO high rate battery with long cycle life)
5）MOSFET: It works as the switch in protective circuit to make sure that the voltages of two ends won’t be up and down, so that the voltage will be stable.
III. Main features:
1. The battery pack has good security, high temperature resistance and long cycle life.
2. The battery pack has long cycle life that meets the principle of low carbon, energy conservation and environmental protection.
3. The battery has BMS system inside with multiple protective functions. Protective system (PCM/BMS) uses Japan and American advanced chip and MOS with equilibrium.
4. Battery materials include LiMn2O4 (lithium manganite), Li-Ni-Co-Mn-O (ternary material), LiFePO4 (lithium ion phosphate).
5. Imported SANYO, Sony, Panasonic, Samsung, LG original batteries and domestic popular battery are available to be assembly unit and make sure the consistency, stability and security of the battery pack.
6. There are battery modular design and combination of batteries connected in parallel and series.