Kokam is one of the world's leading battery manufacturers and solution suppliers. The company designs and manufactures lithium-ion batteries, and they have developed the world's first high-capacity lithium battery. The modern battery solutions are used in aviation, the military, marine, industry, electric vehicles and energy storage systems, all over the world. Since its founding in 1989, the company has specialized in lithium batteries and processing machines.
Kokam has developed water-cooled lithium-ion batteries that are adapted to marine applications with safety measures for in harsh conditions. The batteries are also used in vehicles such as trailers, buses, excavators, and trams, all of which are machines that require high maneuverability, as well as an absorbency so that the batteries can be regenerated. The battery module comes with different types of cells, properties, and chemistry.
Kokam KOL Battery Module
The module consists of cells, BMS monitoring cards, and connectors for electrical connection. In addition, there is support for liquid cooling. The coolant passes through envelopes that are placed between the battery cells and provide optimal cooling on the entire surface of the bag cells. The module can be supplied with two types of cells; 85Ah (High Power Type) and 100Ah (High Energy Type). 12.5 kWh and 15 kWh, respectively.
To achieve 73.6V nominal module voltage, two cells are connected in parallel to form a cell block, and 20 sets of these pairs are connected in series. The total weight of this module is only 125 kg.
A circuit board measures the voltage and temperature of the cells and transmits this information to the BMS system. The module's BMS collects data from 20 voltage channels and 12 temperature channels. This data forms the basis of battery management and protection.
Battery Protection Unit (BPU)
Kokam's battery protection unit (BPU) is installed on each string to ensure safe and reliable operation of the battery system. The BPU is equipped with various safety devices, including string BMS, contactors, fuses and a pre-charge to guarantee safe use.
KOL BPU is the battery protection device that controls and protects the batteries. The main function is to check the connections to the batteries, monitor the status and detect any abnormal conditions,
KOL BPU controls and protects the batteries through the following control, monitoring and safety mechanism:
The main relay controls the main circuit
Two switches cut the main circuit when needed
The pre-charge circuit balances the correct voltage on both sides of the switch before closing it. This feature is very important to avoid damage to the battery system.
A current meter continuously monitors the main current
Strengen's BMS monitors the status of the COPD modules and communicates with an overall energy management system
High performance, 3C continuous charging and discharging on "high-power" KOL
High energy density, 100Wh / kg
High battery life. Minimum 6000 cycles @ 80% DoD, 1C charge / discharge, 70% EOL
Low impedance and thus low heat generation
Low self-discharge speed
High Energy NMC (Nikkel, magnesium, kobolt)
High energy density of the cells (ESS: ~ 203Wh / kg, UHE NMC: ~ 248Wh / kg)
More than 96% efficiency at 0.5C charge / discharge
NMC cells have an optimal balance when it comes to price, performance, reliability and security.
The battery system can be easily installed by connecting the power cables from the BCU directly to an AC / DC or DC / DC converter. It can also be connected directly to a DC bus. If there are several strings so that you need more PDUs (BCUs), you connect these in parallel and to a common bus.
The communication is handled by the Master BMS (MBMS) component which ensures that all strings talk to each other and to the rest of the system. MBMS communicates with the external system via a CAN bus.