Lithium Battery Management System

How a Lithium Battery BMS Works

Ionic’s battery management system consists of a circuit board that monitors each cell in the battery pack. It gauges how much current is safe for the battery to accept, as well as how much can be discharged from it. It sends this information to the battery charger to ensure the battery won’t be overcharged or overdrawn. This is one way that the BMS protects the battery from damage and increases its longevity.

A lithium battery BMS also measures how much energy comes in and out of the battery. This is how it can provide information about the state of charge, or how much energy is left in the battery pack at a given time. When the battery is drained too much, it will shut the battery down to prevent damage.

All LithiumHub batteries have a built-in battery management system. Lead acid batteries generally do not have a battery management system.

Battery Management System Functions

Why a lithium battery BMS is important:

• Keeps battery working in optimal condition
• Prevents thermal runaway and fires
• Makes your lithium LiFePO4 batteries safe for operation
• Shuts your battery off when a problem occurs to prevent damage

Protection from Overcharging and Overdrawing

When you exceed the cell voltage that your battery can handle, it “overcharges”. This can cause irreparable damage. Overdrawing, or over-discharging a battery is when you overdrain it, causing the cell voltage to get too low. The battery management system prevents both of these problems from occurring.

To prevent overcharging, the BMS calculates current limits and sends that information to your battery charger so that it won’t overcharge your battery. When discharging, it measures how much energy can safely leave your battery and sends that information to your load (such as your power inverter or device controller).

Temperature Regulation

Lithium batteries can withstand colder and hotter temperatures than most traditional batteries. But even these high-tech batteries have their limits. That’s why a lithium battery BMS controls and monitors a built-in fan that’s responsible for cooling the battery off when needed.

The temperature regulation function detects extreme temperatures. It shuts down the battery pack when conditions are unsafe.

Problem Detection and Prevention

The battery management system detects the following problems:

• Loose connections
• Short circuiting
• Defective battery cells
• Wire insulation breakdown
• Defective battery fan

These issues don’t occur often. But in case they do, your lithium battery BMS is ready to handle them. The BMS will diagnose the issue and store error codes so that you can make repairs or replace a faulty battery.

Cell Balancing

Another crucial function of the battery management system is cell balancing. A battery is made up of individual cells. Ideally, all these cells should have the same or nearly the same voltage. Your lithium battery BMS balances them by distributing energy from cells that are charged more to those that are charged less.

Here’s why that’s important: a lithium battery will shut off when the cell with the least energy reaches its discharge limit. Cells that still have energy will be left unused. Without a BMS, you would have to charge your battery pack constantly. It will wear it out faster. The BMS ensures the longevity and optimum performance of your battery by keeping the cells in balance. That way, all cells can be fully charged and discharged, and you can harness your battery’s full energy potential.

Other Smart Functions of Lithium Batteries

• Bluetooth Capable
• Built-in heater for extremely cold temperatures (certain models only)
• Fast charging (especially when paired with a lithium smart charger)
• Efficient energy use
• Low self-discharge rate (Only 2% per month).