Why BMS is very important for CCTV Outdoor Cabinet
Table of Contents
Why BMS is very important for CCTV Outdoor Cabinet?
CCTV outdoor cabinet is widely used in CCTV outdoor deployment. It is generally integrated with UPS, battery, POE switch, monitoring and management units. However, the monitoring and management of battery units is often neglected. Because the number of battery cycles is limited, a large number of site batteries that are not monitored and managed will cause various problems for battery replacement and debugging, thereby increasing the operation and maintenance costs of the entire network. Therefore, BMS is a very important functional unit for CCTV outdoor cabinet.
Battery Charge Cycles Are Limited
The battery life is not infinite, and the battery charge cycles of different batteries are different.A charge cycle is the process of charging a rechargeable battery and discharging it as required into a load. The term is typically used to specify a battery’s expected life, as the number of charge cycles affects life more than the mere passage of time. Discharging the battery fully before recharging may be called “deep discharge”; partially discharging then recharging may be called “shallow discharge”.
The battery charge cycles of mainstream battery types on the market are as follows:
- Lead Acid Battery 600-700 cycles
- NMC Lithium-ion Battery/Ternary Lithium Battery 1000-1500 cycles
- LFP/LiFePO4 Lithium Battery 3000-5000 cycles
When the battery charge cycles are exhausted, it is often necessary to replace the battery. LFP batteries have a longer life span and often do not need to be replaced during the entire life cycle of the CCTV outdoor cabinet, but BMS is still necessary because in addition to battery life issues, there are also battery debugging issues that will be introduced in the subsequent chapters of this article.
When the number of sites is large, battery charge cycle affects OPEX
After a CCTV network is deployed on a large scale, the battery usage of CCTV outdoor cabinets in different areas and sites is not balanced. Some sites have more battery cycles, while others have fewer. After the sites have been running for many years, the batteries of some sites need to be replaced. However, the difference in battery cycles at these sites creates problems. There are two strategies:
- Replace all batteries in CCTV outdoor cabinets deployed at the same time in one project
This approach is more common, but it is actually quite wasteful. According to our experience, due to the uneven frequency and time of CCTV outdoor cabinet power grid offline, at least half of the batteries in a phase of a project do not need to be replaced. However, because it is impossible to figure out which sites still have batteries available and which need to be replaced, they have to be replaced uniformly. This actually causes a huge waste.
- Conduct site surveys at each site, determine the list of sites to be replaced, and then replace them.
This site survey method is actually very difficult. Because most CCTV outdoor cabinets are hung high on poles, it is not easy for engineers to complete this task. As the number of sites increases, it takes a lot of man-hours and the cost is very high.
Battery Problem Debug
There are many situations that may cause CCTV outdoor cabinet system offline, such as the three situations shown in the figure above:
- Battery Run Off Cycles
- Battery Cell Unbalance
- Low Battery
Among these three situations, the low battery situation is normal, while the first two are abnormal phenomena. However, if the battery is not equipped with BMS (battery management system), we cannot know whether there is a problem with the site. If you are building a CCTV network for the government or other security departments, when customers complain that there is a problem with the site, you do not have clear information to prove whether the power grid is offline for too long and the battery is exhausted or the battery itself has a problem. Many times, under pressure, you have to go to the site for debugging, which greatly increases the operating cost.
Battery Management System for Outdoor CCTV Cabinet
Therefore, when CCTV outdoor cabinet is equipped with BMS (Battery Management System), it can manage the battery voltage, current, capacity, cell balance and other parameters in detail, and then report the detailed information of the battery to the central software platform. In this way, it is easy to identify the problem of the site battery.
