What is the advantage of BMS – Battery Management System?

BMS – a guarantee for the complete solution

Our lithium-ion batteries consist of two parts: the hardware (the battery pack) and the software (BMS). We have decided to only sell the complete batteries including both cell pack and the BMS software. That way, we can provide a guarantee for the complete package.

Battery cell manufacturers cannot guarantee the operational reliability of a cell as they don’t know if the individual cell is protected from operating outside its safe operating area. The BMS system must obviously also be compatible with the battery pack.

Battery packs bought from us have a plus and a minus pole and a communications bus.

We provide a complete solution – we provide the guarantee. A safe solution for you!

The hardware

The hardware is the battery pack itself, which is built from battery cells by series or parallel connections to deliver the desired voltage and capacity. During the operating time, the cells are discharged. Ideally, all the battery cells have the same remaining charge at any given time and become empty at the same time.


The cells may discharge unevenly however, which may look like this:


The cells discharge as long as any of them are still charged. Discharging of an empty cell may destroy the cell.

The software

The software is called BMS, or Battery Management System. The BMS feature balances the cells in one of the following two ways:

  • Passive regulators: Discharging the cells that have the highest remaining charge

  • Balancers: Redistribution of energy from the most charged cells to the most discharged cells.

It can be illustrated like this:


BMS systems are very beneficial in large battery systems such as in vehicles. The BMS ensures that the battery only operates within its safe operating area. This means protection from:

  • Too high current

  • Too high voltage (during charge)

  • Too low voltage (during discharge / usage)

  • Operation at too high temperature

  • Operation at too low temperature

With the fully configurable BMS system, the software can be integrated to allow the battery to communicate with the product, for example a vehicle:

  • State of charge

  • State of power

  • Temperature

  • Error codes

  • Power saving mode at low charge levels

The battery solution is delivered with an interface where the user can ask questions and get answers. The communications bus is compatible with all existing options.

BMS is the feature that creates value-add for the customer on a market where the hardware is more or less identical. Therefore, the question is: What BMS functionality would add value to my customers?

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

  • An internal power switch is activated.

  • The equipment the battery is connected to reduce or disconnect the use of the battery.

  • Changeover to safety mode if surrounding equipment, for example heaters, fans, air conditioners or coolants stop working properly.



2019-02-22 Year-end report Jan-Dec 2018

In the course of the fourth quarter our net turnover and order bookings continued to increase compared with the same quarter in the previous year (+31.6 and +11.3 per cent respectively) while profit on both group and parent company levels showed weak growth above all due to increased competition and increased cost inflation. The greater and greater need to adapt to a more sustainable use of energy makes the market for Alelion’s products in lithium-ion technology and systems for smart energy management one of the absolutely most promising and interesting.


2019-02-18 Alelion takes a loan of 50 MSEK from majority shareholders

Alelion Energy Systems AB (“Alelion” or “the Company”) has received short term shareholder loans of 50 MSEK (“Bridge Loans”) from majority shareholders Fouriertransform AB, Pegroco AB and Sammaj AB (“the Majority Shareholders”}. Today Alelion’s board also publish summons to an extraordinary general meeting on 2 April 2019. It is proposed that the general meeting decide to authorize the board amongst other things to make an equity issuance of shares for at most 135 MSEK (“the Equity Issuance”).


2018-09-03 Ministerial visit to Alelion's new factory powers up a shared green vision

Energy Minister Ibrahim Baylan discussed electric mobility, innovation and green energy with the West Swedish Chamber of Commerce and Alelion, while touring their brand new Lithium-Ion battery factory - at the heart of Sweden's largest green energy mobility initiative.


2017-03-02 Alelion is looking for new employees

Alelion is growing and is hiring to extend the team.


2016-12-13 New recruitments

Alelion reinforces with five new recruitments


2016-09-09 Cooperation between Alelion and Crown on Lithium-Ion forklift batteries

At the IMHX exhibition, starting September 13th in Birmingham, a selected range of Alelion’s energy storage products, such as the 48-Volt Lithium-Ion forklift batteries, will be visible at the Crown stand 10J61.


2016-09-08 Alelion continues expansion

We are pleased to welcome to our team Åsa Nordström and Magnus Spjelkavik.


2016-09-06 Alelion gets its first order outside of Europe. A distribution centre in Australia chooses lithium-ion batteries for their forklifts.

The total order value for the project runs up to SEK 12 million and Alelion has received its first partial order of SEK 4.45 million. A newly built central warehouse has chosen to equip its complete fleet of forklifts with lithium-ion-batteries from Alelion.


2016-09-05 Alelion undergoes ISO-audit without any remark

In September a current audit concerning ISO-9001 and ISO-14001 was performed without any remark


2016-06-21 Trading begins in Alelion on Nasdaq First North today June 21

Alelion Energy Systems AB (publ), a leading supplier of environmentally friendly lithium-ion energy storage systems for industrial trucks, implements listing of shares and warrants on the Nasdaq First North after passing the listing application. The first trading of the shares will be today 21 June 2016 and for TO1 on 30 June.


2016-04-11 Alelion Batteries AB is looking for a Sales Engineer

We are looking for sales engineers that likes and feels at home in an international environment.