Brill Power’s Intelligent BMS Hopes to “Revolutionize” Energy Storage Systems
Brill believes its new technique in battery balancing can help significantly increase battery life and capacity.
One electronic component that has received the most attention and research in the past decade is the battery, and, even more specifically, battery management systems (BMS). From electric vehicles to renewable energy, many fields and applications are hindered by a lack of storage capacity and battery lifetime.
An example of a general BMS. Image used courtesy of Toradex
Recently, Brill Power, an Oxford University spinoff, has announced a new type of BMS that it claims can boost capacities by over 100% while increasing lifetimes by over 60%.
In this article, let's dive into the challenges facing current BMS and how Brill's approach claims to be "revolutionary."
Why We Need Battery Balancing
In many cases, a lithium-ion (Li-ion) battery pack can consist of several individual battery cells connected in series to achieve the desired voltage.
However, one big challenge that comes from this type of configuration is battery imbalance. Due to variations in manufacturing, temperature, discharge rates, and other factors, each individual cell may degrade at different rates, have slightly different capacities, and have different charge levels relative to its capacity (known as the state of charge).
The current flow of a conventional battery management system. Image used courtesy of Brill Power
The result is that the battery may never achieve its full capacity or undergo deep discharging or overcharging, resulting in decreased battery life.
The battery as a whole is then limited by the weakest cell in the pack. Hence, it's necessary to incorporate a BMS into a system to ensure the cells don't get damaged by overcharging or undercharging due to an unbalanced battery.
Before delving into Brill's specific BMS, it's also essential to understand the two types of battery balancing.
Passive and Active Balancing
In general, there are two main techniques to balance batteries: passive balancing and active balancing.
Passive balancing works by making the stack of cells have the same capacity as the weakest cell. Using a small current, a BMS will drain a small amount of charge from the cells with the highest relative charge during the charging cycle such that all cells contain their overall relative charge.
This balancing is achieved by using a switch and "bleed resistor" parallel with each battery cell. This method is simple but minimizes overall capacity and wastes additional energy in the act of balancing.
Passive balancing circuit scheme. Image used courtesy of Analog Devices
On the other hand, active balancing is a more complicated scheme that works to redistribute charge from battery cells during the charge and discharge cycles.
Example diagram of a 12-cell battery stack using active balancing. Image used courtesy of Analog Devices
In this scheme, system runtime is increased by increasing the total usable charge in the cell stack. Active balancing is more power-efficient and decreases charge time compared to passive balancing, but it comes with a higher circuit and cost overhead.
Now that BMS balancing is a bit more understood let's finally look into Brill's latest BMS.
New BMS from Brill Power
Recently, Brill Power announced its new BMS system, the BrillMS B62 Premium Gen 1, which claims to achieve higher battery capacity and lifetime by optimizing cell balancing schemes.
According to Brill, its new BMS uses distributed control and manages cell currents in proportion to cell health. Using proprietary in-house hardware and software, the BMS implements algorithms to determine every cell block's health and power capability in the battery and follows with specialized control circuitry, which regulates the current accordingly.
Stronger cells are exposed to higher currents and weaker ones to lower currents, ensuring that the system can extract all energy from each individual cell during every discharge cycle.
The new BMS scheme can increase storage by 129% and lifetime by 60%. Image used courtesy of Brill Power
The result of this system is that no single cell limits the energy storage capacity, power capability, or lifetime of the battery system. Overall, Brill has found that its BMS could increase battery lifetime by up to 60% and battery capacity by 129%. On top of this, it increases battery reliability and uptime.
A Revolutionary Discovery?
Overall, Brill believes that its new BMS represents a step-change in improvement compared to active or passive balancing solutions. If its claims are true, and capacity and lifetime can be increased significantly simply with the addition of its new BMS, the implications could be huge. It will be interesting to see where Brill's BMS technology heads to in the future, and what other companies create to keep battery management evolving.
Interested in learning more about other battery management innovations? Read on in the articles down below.