What is a battery management system?
A battery management system is an essential component in a lithium-ion battery system. Many of EcoFlow’s products feature the best-in-the-business choice of LFP (or LiFePO4) batteries — a newer subset of lithium-ion batteries.
LFP batteries are unparalleled in performance, but a BMS (Battery Management System) is essential to making it all work.
Think of the BMS as your battery’s brain.
A BMS uses software and hardware to manage and monitor every aspect of your battery’s performance. One of its most crucial functions is to protect the LiFePO4 battery cells so they function at the optimal temperature, current, and voltage. Keeping your battery operating within its operating safety parameters is the essential job of the BMS.
Additionally, your BMS calculates the battery’s remaining charge, monitors the health and safety of the battery by checking for internal shorts and loose connections, and tracks the battery’s operating temperature. In addition, it balances the electrical charge across the cells, optimising each cell’s performance.
If unsafe conditions are detected that the BMS can’t address, it shuts the battery to protect the portable power station and its users.
In short, a BMS is a combination of hardware and software components that function as your battery’s “brain” and protect the longevity and health of your battery.
Most importantly, if a severe fault or condition occurs, the BMS will shut down the device to ensure safety and prevent any possibility of fire.
What is a BMS and Why is It Necessary in Portable Power Stations?
There are many different battery chemistries you might opt for in a portable power station. But there are many reasons why lithium-ion batteries — specifically LiFePO4 batteries — are an industry favourite.
Portable power stations equipped with a lithium-ion or LFP battery require a BMS for numerous reasons. The most crucial are:
- Optimising operating efficiency
- Calculating charge level
- Staying within safe operating parameters
- Extending the cycle life of the battery
- Acting as a fail-safe if a system failure or unsafe conditions arise
How Does a BMS Improve the Performance and Longevity of Portable Power Station Batteries?
Battery management systems are designed to monitor and optimise many aspects of your battery’s operation. BMSs do not follow a standard set of functions across manufacturers.
Generally, a BMS optimises performance and protects your battery from damage to maximise its longevity and efficiency.
A BMS monitors the individual cells within your battery pack and calculates how much current can enter safely (charge) and flow out (discharge) without damaging the battery.
Doing so prevents the power source (battery charger) and load (from an inverter) from overcharging or overextending the battery. This protects your battery from over and undercharging and helps to extend its lifespan.
Thermal management — regulating the battery’s temperature — is another essential function of most BMS. Overall, battery capacity is reduced in low temperatures due to chemical reaction rates slowing down considerably. Charging below 32 °F (0 °C) is physically problematic as the anode can experience the phenomenon of lithium plating during charging.
Lithium plating causes permanent damage that reduces battery storage capacity and leaves cells more susceptible to failure if subjected to stressful conditions like vibration. If your BMS uses heating and cooling to control the battery pack’s operating temperature, it will keep the battery healthy and lasting longer.
The features of a BMS vary between models. The essential function of a BMS is safety. However, maximising performance and longevity comes a close second.
A BMS helps you get the most out of your portable power station or solar generator by monitoring the battery and making system adjustments to optimise performance.
The Role of a BMS in Ensuring Safety in Portable Power Stations and Solar Generators
A smart BMS comes with numerous benefits, but the primary responsibility of any Battery Management System — regardless of model or manufacturer — is the safety of you, your family, and the device.
The liquid electrolyte contained in lithium-ion batteries is highly flammable. To prevent fires, a BMS performs multiple functions to ensure the battery operates optimally within its limits at all times to prevent a fire from occurring.
During both charging and discharging, it’s critical that the temperature, current, and voltage of any monitored component or battery cell do not exceed the defined SOA (safe operating area) limits.
If these limits are exceeded briefly, your battery could be damaged. But more crucially, extended operation outside of SOA can lead to the dangerous effect of thermal runaway.
Thermal runaway in Li-ion batteries is a positive temperature feedback effect that occurs when more heat is generated than there is cooling or insulation capacity to manage it. Thermal runaway should be avoided at all costs and carries the risk of fire or even explosion.
A quality BMS from a reputable portable power station or solar generator will help ensure that a thermal runaway event never happens.
Types of Battery Management Systems in Portable Power Stations
Clearly, having a battery management system in a portable power station or solar generator is essential.
But what different types are out there?
Let’s go through some of the different types of BMS on the market and help you decide which option is right for you.
Passive BMS vs Active BMS
Cell Balancing
In a battery pack “stack,” the performance of cells is not equal. There will be variations in self-discharge rates between cells. The cells may have been equally matched when new. But, with time and use, numerous factors cause individual cells’ discharge rate and performance metrics to diverge.
You can’t “overcharge” a lithium-ion cell. Additional power input into a Li-ion battery after it’s fully charged becomes heat. Once a battery heats up to the point that it’s operating outside its SOA, fast-rising voltage and a possibly dangerous situation (such as a fire) can arise. Overheating can also permanently damage the cells.
A mismatch between adjacent cells can be problematic when charging your stack. If cells charge up equally, they’ll reach their operating threshold together. However, if cells are unbalanced, one cell will reach its capacity first. The input current must be cut off before the rest of the cells reach their total charge capacity.
The solution?
A BMS, of course. A BMS can manage this in two ways.
Passive balancing is easier to implement. It artificially lowers every cell in a stack’s full capacity to match the charge capacity of the weakest cell in the array. With a relatively low current, a small amount of energy is shuttled from cells with a high state of charge while charging, so all cells charge to the max state of charge.
By contrast, active balancing redistributes charge rather than simply dissipating it. As a result, your system run-time is increased, and your charging efficiency should also increase.
Temperature Control
Like cell balancing, temperature control can be achieved through passive or active methods — or a combination of the two.
With passive cooling, airflow cools the battery. This can be more sophisticated than it sounds. Airspeed sensors may be integrated, strategically auto-adjusting deflective air dams and maximising airflow.
Active temperature-controlled fans can also kick in, but the best this can do is equalise the battery with the ambient temperature surrounding it. If it’s sweltering outside, fans could even increase the temperature of the battery cells.
Thermal hydraulic active cooling can also be used, circulating an ethylene-glycol coolant in a specific ratio through specific components against the battery pack assembly. The battery management system monitors the temperature throughout the pack and closes and opens valves to maintain an ideal temperature range for peak battery performance.
Real-World Applications of Battery Management Systems
No matter what portable power station or solar generator you choose, a BMS serves the essential functions of keeping your battery system at operating peak performance, maximising longevity, and, most crucially, keeping the battery running within its safety parameters.
Here are some situations where a BMS is invaluable in the real world:
BMS in Residential Off-Grid Power Systems
If you want to eliminate your reliance on the ageing utility grid or fossil fuels and achieve energy independence, you’re probably considering off-grid solar power solutions for your electricity needs.
Solar is really the only clean, renewable energy source that makes sense for most residential use cases. Wind and hydropower are incredible large-scale clean energy sources, but making them work for a single home is challenging.
Fortunately, residential solar tech has shot up in quality and plummeted in price in recent years.
Plus, there’s a BUNCH of government incentives for switching your home to solar.
The sticker price can be a shocker, but it’s worth the investment over the long term. Once your solar payback period is over, all that money you save on electricity bills goes straight into your pocket.
EcoFlow is a leading manufacturer of off-grid residential power solutions. Whether you’re looking to reduce your electricity bills — or eliminate them altogether — EcoFlow probably has the solution for you.
If you want to generate electricity for your family home, a whole home generator solution could be the answer. Maxing out at 7200W starting watts of AC output and 14,400W of running watts (surge power) with X-Boost, this system can run just about any number of household appliances and HVAC systems simultaneously.
With enough solar panels (up to 8 x 400W rigid PV panels) for electricity generation and battery storage capacity (up to 25kWh max), it can also operate indefinitely.
If you’re looking to live off-grid AND on the road, the full-time motorhome life offers unparalleled freedom — especially if you’re not reliant on shore power and motorhome campsites with electricity hookups.
EcoFlow’s Power Kits are tailor-made for electricity generation on the move. With a compact, modular build that works for a standard van as well as it does for a large motorhome, there’s a Power Kit option that’s right for you.
With battery storage options ranging from 2kWh to 15kWh, you have plenty of options to choose from. Check out the online calculator to see which is right for you.
EcoFlow’s current line of portable power stations, solar generators, and off-grid power solutions feature state-of-the-art LifePO4 (LFP) battery chemistry.
EcoFlow’s LFP batteries charge faster and last longer than any competitors on the market. EcoFlow’s proprietary Advanced Battery Management System (BMS) is a big part of the reason for that.
A dedicated smart BMS is built into all of EcoFlow’s portable power stations, power kits, and solar generators: from the tiny RIVER 2 to the mighty DELTA Pro.
The advanced BMS regulates your EcoFlow products’ vitals, including voltage, current, and temperature, to ensure it’s operating safely and optimally at all times. Thanks to LFP battery chemistry and Advanced BMS, you’ll enjoy off-grid electricity for years (or decades) to come — maintenance-free.
BMS in Portable Power Stations for Camping and Outdoor Adventures
Who doesn’t love an outdoor adventure? If you love spending time in nature without forgoing the comforts of home, the RIVER 2 PRO is your perfect companion.
When you’re on the go, battery storage capacity is critical. EcoFlow’s built-in BMS helps make RIVER 2 Pro go for as long as possible between charges. It also enables the RIVER 2 Pro to cycle (fully/discharge) 3,000 times without any noticeable drop in performance.
That’s a lot of camping trips!
Final Thoughts
A Battery Management System (BMS) is essential to any lithium-ion or lithium iron phosphate (LiFePO4) battery-powered device.
A well-designed BMS protects your battery, optimises its performance, extends its cycle life, and, most crucially, keeps the people using it safe.
At EcoFlow, all of our Li-ion and LiFePO4-powered products offer advanced BMS protection — built in.
That means faster recharging, longer cycle life, peak performance — and protection if anything ever goes wrong with your battery.
FAQs
Does BMS Prevent Overcharging?
Yes, a battery management system (BMS) protects your battery in many ways, including preventing it from overcharging – which with Li-ion batteries actually means overheating. It also protects it from undercharging, unsafe temperature fluctuations, imbalances between battery cells, and much more.
Does a BMS Handle Charging?
An external power source charges your Li-ion or LiFePO4 battery. Typically, that’s an AC wall outlet, solar panel, car adapter, or another energy source. A charge controller (typically MPPT or PWM) does most of the heavy lifting when it comes to managing your battery’s external power source and charging. However, the BMS conducts many functions to help ensure your battery’s longevity, health, and safety.
Will My Battery Work Without the BMS?
Technically, a Li-ion or LiFePO4 could operate without a BMS. But it might explode. You should never use a lithium-ion or LiFePO4 battery without a BMS. Not only does a BMS ensure the safety of the device and people who use it, but it also protects the health and lifespan of your battery.