Battery Management System (BMS) is essential for maintaining the health and long life of the battery pack. However, if you ever tried to purchase one or replace an existing BMS, then you might have encountered several technical questions. The purpose of this guide is to help you get familiar with such technical terms related to BMS as well as to perform the required calculations that help in finalizing a BMS for your battery.
BMS Selection
Selecting a BMS suitable for your battery pack depends on some important aspects. You should consider the below points to select the right BMS:
- Series combination of the battery
- Total ampere-hours of the battery
- Cell type
- BMS Brand
Series combination of the battery
The series combination of the battery is calculated by dividing the total voltage of the battery pack by the nominal voltage of the cell. For instance, if the total voltage of the battery is 64 and the nominal voltage of the cell is 3.2 then the series combination of the battery will be the 20S. (64 / 3.2 = 20)
Meaning you will need to purchase a 20S BMS for that battery. When you use appropriate BMS, the battery performance improves dramatically. If you go for a lower value then you cannot use the total efficiency of your battery and if you choose a much higher value, you might overspend on unused resources.
Total ampere-hours of the battery
We calculate the total ampere-hour of the battery by multiplying the ampere-hour of the individual cell and parallel combination. For example, 5AH cell with a parallel combination of 4 then the total ampere-hour of the battery will be 20AH. (5 x 4 = 20)
It implies that you will require a BMS with a rating of 20A or above for it to guard your battery.
Cell Type
The nominal voltage of each cell depends on the cell type used in the battery. Hence it is important to note the chemistry of the cell before looking for a BMS. For instance, the nominal voltage of Li-ion Cells is 3.7, Lifepo4 Cells is 3.2, LTO Cells is 2.4, and so on.
Knowing the cell type helps in calculating the voltage range as the nominal voltage is different for different types of cells.
BMS Brand
Not all BMS are made equal despite having similar values. They differ in several ways from quality to their standards. Even branded BMS differ a lot in their performance. So, you must choose trusted and popular brands which are reliable and offer excellent performance to their users.
Brands such as DALY, JBD, ANT, and JK are popular among BMS. Among them, DALY, JBD, and ANT are passive BMS with passive cell balancer inside it whereas JK BMS is active BMS with an active cell balancer inside it.
All the DALY BMS are waterproof which makes them suitable for E-bikes, boats, and camping batteries. JBD, ANT, and JK BMS are good to use in household applications. So, based on your requirement and where you will be using the battery, you should choose the BMS to withstand the conditions it might be subjected to.
It is important to check if the brands follow safety norms and have proper approvals and certifications before you trust them.
Different types of battery BMS
We have two different types of battery BMS i.e., Passive BMS and Active BMS.
Passive BMS
It works by discharging the battery with a higher voltage until both the batteries have exactly the same voltage. Their setup is easy and they are inexpensive. Even the operation is simple. Every individual cell in the balancer is connected in parallel to a resistor to keep the cells balanced. The BMS activates the resistor whenever the cells are in an unbalanced state. This resistor connected to the high voltage cell drains the voltage of the cell until it becomes equal to the adjacent cells. Once the process is done the BMS switches off the resistor.
Active BMS
Unlike resistors in passive balancing, active balancing uses inductors or capacitors to balance the batteries. In this process, all the extra energy from the higher voltage cell is used to charge other batteries with lower voltage. This method has higher efficiency but is more expensive than a passive setup.
We at SRIKO batteries offer several high-quality BMS with various configurations that cover almost every BMS need of yours.
Please follow the link for BMS.
https://srikobatteries.com/?s=bms&product_cat=0&post_type=product
(I suggest this link instead of the below link)
Advances in BMS
There are many smart BMS systems with a lot more sophistication and features that help you perform various advanced actions. You can find Bluetooth connectable to programmable BMS, which offers cutting-edge technologies for your hi-tech projects.
They can connect to an electronic device for custom programming. Many smart BMS works with the Android interface. They communicate with your phone through an app using Bluetooth. Such BMS allows you to monitor the battery at a cell level.
Conclusion
Battery Management System (BMS) has numerous advantages when applied correctly. It not only saves your expensive battery from compromising but also optimizes your battery performance. BMS also keeps your battery fit in various thermal conditions by not letting it run into trouble when the temperature is not favorable.
Once you figure out the appropriate BMS for your battery, you can enjoy a safe and reliable battery. If you need any further assistance or have any concerns about BMS feel free to comment below. With so many options and several configurations, it seems like an overwhelming task to find the perfect BMS for a battery. We shall be happy to suggest a suitable BMS for your battery if you provide the specifications.
