Why don't UPS batteries use lithium batteries?
2021 01/12
Lithium battery has many advantages, but it can not be used in UPS power supply battery for a long time. Why? The main reason is the high cost design threshold of lithium battery, which makes it difficult for ordinary manufacturers to replace lithium battery.
Due to the different characteristics of lithium battery and lead-acid battery, the charging curve and circuit are different, and the charging equipment varies with the UPS power supply of different brands and specifications. Therefore, it is almost impossible to directly replace the lead-acid battery with lithium battery when the old UPS battery client replaces the battery every year. What's more difficult is that the lead-acid battery specifications are 12V, and the capacitance ranges from 7Ah to 70ah. To 500ah or higher, the lead-acid batteries are stacked in series and parallel according to the demand.
However, UPS lithium battery pack has a protection board BMS to control overshoot and overdischarge. Therefore, if the current lithium batteries are stored in a unit (assuming 48V, 30ah) with a voltage and capacitance in the form of lead-acid batteries, and then stacked in parallel according to the power demand of each computer room, there will be a problem between BMS of each lithium battery pack. Because the existing voltage and power of each battery pack are different, it will produce a protection condition when charging or discharging and cannot be used.
UPS power supply battery does not need lithium battery, UPS is mainly a price problem, and its application scope is not wide. At this stage, most of the lithium battery ups are still used in some special projects with relatively high requirements, but the mainstream is lead-acid battery UPS, after all, the price can not be compared. Lithium batteries are two to three times more expensive than traditional lead-acid batteries.
Does UPS still use batteries instead of lithium batteries?
The price of traditional lead-acid battery UPS is low, and its service life is as long as five years. However, the price of lithium-acid battery UPS is high, which can meet the situation that lead-acid can not meet, such as volume, use environment, etc. in general, there are no special requirements for data center, special vehicle, modified vehicle, etc., so as to save costs. The main problem is the cost. Although it is better than lead-acid battery in volume, weight and safety, if users do not have the rigid requirements in these aspects, they will basically give priority to lead-acid battery. After all, lithium battery UPS is still in the promotion stage.
Most manufacturers still don't support lithium-ion batteries. Moreover, the market share of lithium-ion battery UPS accounts for a very small proportion of the whole UPS market, and many manufacturers are not willing to spend too much manpower and material resources to promote this one. This leads to the reason why the ups battery power supply in the market uses lead-acid batteries rather than lithium batteries.
Is it better to use lithium battery or lead acid battery for UPS power supply?
Advantages of lithium battery:
The ups battery uses lithium battery with smaller volume and lighter weight. The volume of lithium battery is 2 / 3 of that of lead-acid battery, and its weight is about 1 / 3 of that of lead-acid battery. Lithium batteries of the same volume have higher capacity than lead-acid batteries.
Long life: LiFePO4 battery pack has a longer service life under the same conditions, and the general service life is about 4 to 5 years.
Excellent high temperature performance: the thermal peak value of LiFePO4 battery can reach 350 ~ 500 ℃.
Fast charging: high current 2C fast charging and discharging, the battery can be fully charged within 40 minutes under 1.5C charging with special charger.
Safe and reliable: LiFePO4 has passed strict safety test, and it will not explode even in severe collision.
Green environmental protection: in line with European ROHS regulations, it is a green environmental protection battery.
No memory effect: it can be used at any time without discharging completely before charging.
Good performance: powerful, fast charging and discharging.
Advantages of lead-acid battery:
The price is cheap, and a considerable number of manufacturers choose to use lead-acid batteries in order to apply the cost to other structures of electric vehicles;
The concept of repairable, battery repair can extend the service life has been recognized and accepted by the majority of customers, and the old can be replaced if it is damaged within the scope of warranty;
Very high impact strength, strong ability to "fight", will not cause damage to the battery due to some bumps at ordinary times;
ABS resin in lead-acid battery has excellent thermal performance.
Compared with the performance advantages of the two, the use of lithium battery in UPS power supply is better. The use of lithium battery perfectly avoids all the effects of lead-acid battery. The advantages of high energy density, small volume, light weight, long service life and wide range of service temperature make the market "dump" on it. The advantage of using lithium battery as UPS battery power is more and more obvious, and the lithium battery construction scheme is also adopted by more and more enterprises. We also see that lithium battery is becoming an indispensable new friend of data center room step by step.
With the wide adoption of China's communication operators and data centers, as well as the maturity of technology and the reduction of material cost, it should be a trend for UPS power batteries to use lithium batteries as energy storage devices.