A battery must be protected against the effects of wear and tear and against electrical mishandling. It must also be kept in a safe working environment. In addition, a battery must be cared for and maintained properly to ensure long term performance. To do this, many different methods are employed.

Lithium-ion batteries have a lot of advantages over their lead-acid counterparts. They’re lighter, more efficient, charge faster, and have a longer lifespan. However, they’re susceptible to conditions that can damage the battery pack. Tapping into all of this potential requires lithium-ion batteries to be more complex and include components to help avoid these damaging conditions. In fact, this is the primary purpose of the battery management system.

What is a BMS?

A battery management system (BMS) is said to be the brain of a battery pack. The BMS is a set of electronics that monitors and manages all of the battery’s performance. Most importantly, it keeps the battery from operating outside of its safety margins.

One of the most common methods of batteries upkeep and management is through the management of the charge profile of the battery. Charge management basically means the management of the amount of current that flows into and out of the battery. When a battery is newly charged, it is very easy to allow the stored charge to far exceed the available current. This causes very dangerous chemical reactions within the battery. The end result is the destruction of the battery and complete failure.

Batteries require constant recharging if they are to remain functional over a long period of time. Recharging a battery depletes the available charge and causes it to become discharged, or what is commonly referred to as "dead". The reason a battery becomes dead is because the chemical bonds within the battery have been weakened over a period of time and it needs to be restored. By recharging a battery, much needed life is restored but recharging a battery too much can actually damage the battery beyond repair. The best way to restore a battery is through the use of what is called a battery regeneration system. 

When there is a surplus of battery packs in an array, it is important to make sure that they are not prematurely charged or discharged. This will result in excessive power drainage and can even lead to overheating and burn out of the array. This is where the function of a battery management system comes in. The system monitors the charge level of the batteries, detects when the maximum capacity of a particular battery is reached and shuts down the charging process if required.

Thus, the battery management system is critical to the battery’s safe operation, overall performance, and longevity. Moreover, it protects whatever the lithium battery is installed in (boat, RV, etc.) and the people who are using it.

What is the main function of a BMS?

The main function of a battery management system is to monitor the charging and discharging of lithium-ion batteries. It keeps track of the condition of the batteries, which in turn helps in determining the charging rate of the battery pack. Most of the systems come with user-friendly graphical interfaces that allow easy navigation. In addition to this, they are also easy to install and can be removed without any hassle.

The primary function of the BMS is to protect the battery cells from damage caused by being overcharged or over-discharged. Additionally, the BMS calculates the remaining charge, monitors the battery’s temperature, monitors the battery’s health and safety by checking for loose connections and internal shorts. The BMS also balances the charge across the cells to keep each cell functioning at maximum capacity. If it detects any unsafe conditions, the BMS shuts the battery down to protect the lithium-ion cells and the user.

The latest battery management systems are more affordable than ever and have helped in the reduction of the mounting maintenance costs of lithium-ion batteries and other energy storage devices.

How does a Battery Management System work?

The battery management system monitors individual cells in the battery pack. It then calculates how much current can safely go in (charge) and come out (discharge) without damaging the battery.

The current limits prevent the source (usually a battery charger) and the load (such as an inverter) from overdrawing or overcharging the battery. This protects the battery pack from cell voltages getting too high or low, which helps increase the battery’s longevity. The BMS also monitors the remaining charge in the battery. It continually tracks the amount of energy entering and exiting the battery pack and monitoring cell voltages.  It uses this data to know when the battery is drained and will shut it down. This is why lithium-ion batteries don’t show signs of dying like a lead-acid, but just shut off.   

One of the main components of the battery management system is the charger itself. Many chargers in the market already come with a battery management system, so if you are looking for one then all you need to do is purchase a compatible charger. However, before purchasing any product you must make sure that you are buying from a genuine manufacturer. 

Click the following link to find out more about Van der Leun’s battery solutions and partnership with one of the industry’s energy storage experts, Van Alfen.