First, the choice of battery capacity The standard calculation for UPS battery capacity is as follows: Calculate the maximum discharge current value of the battery : Imax = Pcosф / (η * E critical * N) Note: P→ nominal output power of UPS power supply Cosф→output power factor of UPS power supply (UPS is generally 0.8) The efficiency of η→UPS inverter is generally 0.88~0.94 (0.9 can be taken in actual calculation) E critical → critical discharge voltage of the battery pack (12V battery is about 10.5V, 2V battery is about 1.7V) N→The number of batteries in each group is based on the backup time of the selected battery pack, and the required discharge rate value C of the battery pack is found, and then according to: The nominal capacity of the battery pack = I maximum / C time and discharge rate C Second, the power supply time calculation Battery power supply time is mainly affected by factors such as load size, battery capacity, ambient temperature, and battery discharge cutoff voltage. Generally calculate the UPS power supply time, you can calculate the battery discharge current, and then find the discharge time according to the battery discharge curve. The battery discharge current can be calculated according to the following empirical formula: Discharge current = UPS capacity (VA) × power factor / battery discharge average voltage × efficiency To calculate the actual load discharge time, simply change the UPS capacity to the actual load capacity. From the above formula 780/0.6=1300W=1.3KVA, the mountain C3KS is 3KVA capacity should be able to maintain 2 hours of power, if you are afraid of not enough, you can choose the capacity of 5KVA, of course, the price is more expensive than 3KVA. If you are a little complicated about the above calculations, there is an easy way: if you want to calculate, you need to convert the actual load W to VA. The general power factor of the device such as server is 0.8 (or 8000/0.8=10000VA if it is 8000W). The selection of battery packs, now the mainstream battery is 12V, the difference is "AH number", but also the "Amp number", the battery requirements of the general UPS are all multiples of 12. Speaking of this, I don't know if you understand it. For example, if the battery pack is 24V, then you should use two sets of 12V parallel (so you should be clear?) Another AH number is the battery standard, there are many. Then we even count the number of batteries in each battery, a very simple algorithm, but not very accurate (battery pack voltage * AH * number of batteries = load power * delay time) according to this you calculate the number of batteries can be It is. When designing the UPS power supply system of the communication equipment room, the management personnel must not only meet the requirements of the UPS brand and model, but also know how to maintain the UPS continuous work on the key, thus saving investment and realizing the reliability and flexibility of the system. Equipment and computer load provide effective protection. Plastic Leveling Ramp,Adjustable Plastic Leveling Feet,Folding Ruler Wood Kacy Tools Co., Ltd. , http://www.jhspiritlevel.com