What is the advantage of the BMS – Battery Management System?

BMS – everything is under warranty

Our lithium-ion batteries consist of two parts: the hardware (the battery pack) and the software (BMS). We have opted to only sell complete batteries which include the cell pack and the BMS software. This means we can provide a warranty on the entire package.

Manufacturers of battery cells cannot guarantee cell reliability, as they do not know how the individual cell will be protected from use which is not within its safe operating range. And of course the BMS system must be adapted to the battery pack if the manufacturer is to be able to provide a warranty on this component. What you buy from us is a battery pack with a positive and negative pole plus a communication bus.

We provide the entire product and the warranty for it. A safe solution for you!

The hardware

The hardware consists of the battery pack proper, which is built up from the battery cells connected in series or in parallel so as to deliver the desired voltage and capacity. During the operating period, the cells discharge. In an ideal scenario, the remaining charge in the battery cells is uniform throughout the entire period, so that they all become exhausted at the same time.

 

However, it can happen that discharge occurs in a non-uniform manner. It may then look like this:

 

The cells carry on being discharged for as long as one of them contains a charge. If one cell continues to discharge when it is empty it can get damaged.

The software

This is where the software comes in. It is called BMS, or Battery Management System. The BMS function balances the cells in one of the following two ways:

  • Passive regulators: Emptying those cells which have most charge left in them
  • Balancers: Redistribution of energy from the cells with the most charge in them to those which are most empty.

This may be illustrated as follows:

 

A BMS system is particularly valuable when it comes to larger battery systems such as in vehicles. It ensures the battery only operates within its safe operating range. This means it is protected against:

  • Too high a current
  • Too high a voltage (during charging and use)
  • Too low a voltage (during discharge/use)
  • Operation at too high a temperature
  • Operation at too low a temperature

The fully configurable BMS system means we can incorporate software to enable the battery to communicate with the overall product. So, for a vehicle for example:

  • Charge status
  • Remaining driving time
  • Temperature
  • Error codes
  • Energy saving mode at low levels of charge

The battery solution is supplied with an interface where the user can ask questions and obtain answers. The communication bus is compatible with all available versions.

BMS is the function which creates customer added value in a market where all the hardware is pretty much identical. So the question you should be asking is this: Which BMS functions would enhance the value for my customers?

BMS can disable activity outside of the battery’s safe operating range in three ways:

  1. An internal cut-off switch is activated.
  2. The equipment the battery is connected to reduces or terminates its use of the battery.
  3. Transition to safety mode if the ambient environment control equipment, e.g. heater, fans, air conditioning or fluid cooling stop functioning correctly.