For more than 15 years, GWL a.s. has been testing, researching and supplying only the highest quality LFP battery cells. Under the Amvolt brand, GWL has developed complete battery storage system in a wide range of sizes and applications. Available as final products or as production blueprints for localized assembly anywhere in the world.

AMVOLT BATTERY
CONTAINERS

(70 kWh – 1 MWh)

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Basic Description

The main principle of the Amvolt battery storage concept is technical openness, i.e. no vendor lock-in for our customers. This of course also applies to our containerised battery storages. Unlike smaller Amvolt Battery Packs for indoor use, Amvolt Battery Containers come with their own specially developed inverters. They are connected to a mains voltage of 3 x 400 V AC and inside the prismatic LFP cells are connected to a voltage of approximately 700 V. Our containers are made of 71,7 kWh standardized, modular battery boxes and there can be up to 14 of them in a 40-foot container, so 1000 kWh in total. All completely assembled in the Czech Republic.

In contrast to closed "shelf" storage solutions, Amvolt storage systems use prismatic LFP battery cells (easy to replaceable individually), to which we have a good strategic approach, and the electrical components (BMS, protection, etc.) are handled in the form of industry-standard modular devices.

Who are Amvolt Battery Containers suitable for?

Customers of Amvolt Battery Containers are owners/operators of LDS, large PV plants, MVE, industrial sites, etc.

Amvolt container storage systems are sold in consortium with carefully selected regional suppliers, including control system and monitoring (optional), installation and commissioning, usually as a complete PV plant service. Thanks to large-capacity storage, customers also get the possibility to participate in trading (VDT, DT) and SVR in the future (now also, but more difficult, depending on the region). We can also facilitate and help set up such services.

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Most Suitable Use

Peak shaving mode

Maintaining the maximum set power consumption of the customer's object until the battery is discharged, then charging so that the maximum power consumption is not exceeded. No remote control is needed for this mode, the Amvolt Battery Container manages itself thanks to its own knowledge of the consumption at the foot of the object.

Trading mode

Proportional control of the charging and discharging mode from the external dispatcher up to the maximum storage capacity. All Amvolt batteries are symmetrical, i.e. they can charge and discharge with the same power. For this mode, remote control by a higher-level system is required, which needs to be connected to other sources such as the intraday market, grid operator dispatching, etc. The battery management API is accessible via HTTPS/TCP/IP, TCP ModBUS, RTU/RS485 or other protocols as agreed with the customer.

Saving mode

The battery knows the current consumption in the building thanks to a remote electricity meter at the foot of the building, as well as the current real-time production of one or more generating plants (PV, cogeneration...) in the area. The internal smartness of the battery thus limits the charging only to the surplus from its own production, not from the grid. It guarantees that all the energy from own production is consumed and only then the energy from the grid is used. No remote control is needed for this mode, the battery manages itself thanks to its own knowledge of the consumption at the foot of the building.

Back-up mode

It might seem that the battery is mainly for backup against power failure. Paradoxically, however, this is the least demanded function. However, we are preparing Amvolt Battery Containers for backup and off-grid operations in Q4/2022, for now, we focus on the functions mentioned in the previous paragraphs.

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Design and Operating Information

Standard ISO certified container of 10, 20 or 40 feet, openable from one side. Resistant to all common weather conditions.

The storage is designed for climatic conditions from -20 °C to +40 °C.

The internal storage temperature is automatically maintained at +15°C to +35°C.

The maximum loss heat capacity of the battery is max 1 kW per 50 kW of output and is cooled by a combination of a hydraulic heat exchanger and an air-to-air heat pump.

The walls, ceiling and entrance door of the Amvolt Battery Containers are thermally insulated with a heat transfer coefficient of 0.60 W-m2K and a fire reaction class B-s2, d0.

The main connection point for electricity and other utilities is brought in from the side of the container, inside the container the cables are terminated on an internal terminal block with fusing and disconnection.

The standard part of the Amvolt Battery Container is a system for maintaining the internal environment, monitoring and security (temperature, movement, humidity, pressure, image, smoke...).

The outer outline of a standard ISO shipping container is enhanced with an outdoor air conditioning unit, heat exchanger and signal beacon. Everything is demountable for transport to maintain standard dimensions.

The Amvolt Battery Container is placed on a raised foundation or on concrete footings, above the level of the surrounding ground. It can be fixed with twistlocks to the concrete base (not included in the price).

The whole solution is designed in such a way that any service intervention or opening of the container door can only be carried out by trained and qualified personnel of the storage facility operator and intervention in the wiring can only be carried out by a person authorized to do so or by the manufacturer/supplier of the storage facility.

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Battery Cells

Amvolt battery storage systems, whether Battery Containers or Battery Packs for indoor usage, are assembled in a modular and tailor-made manner. We use industrial LFP (LiFePO4) prismatic cells of world-renowned brands Winston and Elerix, which are supplied by our parent company GWL a.s.

The cells are characterized by high safety and long service life, they are non-flammable and non-explosive. The usual lifetime of a cell is up to 8 thousand cycles, but even after that, the cells can be used for many more years without any problems. In the event of damage to some of the cells in the storage unit, the other cells can be reassembled and used again or the individual cells can be replaced – so the entire storage unit is not damaged, as is the case with closed battery packs and containers.

That's why for each Amvolt storage unit, we always recommend purchasing spare cells with a capacity of 1–5 % of the total capacity. You can learn more about LFP battery cells in the Technology section.

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Inverters in Amvolt Battery Containers

The Amvolt HV 750/200 inverters (AC mains – DC battery) manufactured in the Czech Republic are one of the main advantages of Amvolt high-voltage container solutions. Thanks to the inverter custom developed for Amvolt, our Battery Containers do not need a transformer or DC/DC converter, which increases reliability and reduces losses.

The control processor electronics of the inverter ensure the quality of the required parameters for connection to the distribution network. The inverter is phase symmetrical and fully reversible, i.e. it can charge and discharge the battery at full power and the transition from charging to discharging mode is a matter of tens to hundreds of milliseconds. It is suitable for almost unlimited parallel wiring and thus unlimited power scaling.

The inverters are hydraulically cooled, reducing the thermal management requirements of the BESS internal environment. Waste heat is immediately removed from the battery compartment and radiated to the surrounding environment. With a low-temperature gradient of only 2 °C, the inverter can be easily cooled passively even in the summer months. The inverter is controlled by an internal PLC unit based on standardized WAGO modules.

Basic technical parameters:

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Amvolt Battery Container Block Diagram

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Basic Modular High-Voltage
Amvolt 71.7 kWh Box

Amvolt Battery Containers are composed of a selected number of the basic Amvolt high-voltage (650–800 V) module 71.7 kWh battery boxes. Each of these battery boxes consists of two parts:

a) The individual battery cells with the BMS system are located on the right side of the box.
b) The master module of the BMS system and all of the battery cabinet's circuit breaker power elements are located in the left part of the battery box. The cable exit from the box is routed upwards.

Each Amvolt 71.7 kWh battery box contains 224 pieces of Elerix EX-L100K cells with a total nominal voltage of 720 V and a capacity of 100 Ah. These battery boxes are connected in parallel on a DC bus with the same nominal voltage.

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Amvolt Battery Container 70–210 kWh

10-feet container

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Amvolt Battery Container 280–430 kWh

20-feet container

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Amvolt Battery Container 500–1000 kWh

40-feet container

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Monitoring and Storage Management

Control System

The Amvolt Battery Containers include a control system with PLC, which provides monitoring and management of the entire storage and basic smartness, see description.

The PLC monitors container temperature, humidity, liquid pressure in the inverter water cooling system, inlet opening, movement of people in the storage, smoke occurrence and signaling of all important operational and emergency conditions.

The PLC is ready for data communication with a higher system (e.g. RTU/RS485, ModBus, TCP/IP).

Inside the storage there is a touch / button LCD control panel for quick view of the operating status and control of basic functions.

Remote Control

The fixed internet connection (UTP/fiber optics) is secured by an internal MikroTik router and routed to other modules. The router has a 4G/LTE modem in case the fixed internet connection is down.

For service needs, the storage is equipped with internal WiFi coverage and an RJ45 socket to connect a computer/mobile phone to the storage's internal data network.

An LCD panel fitted into the door of the internal consumption box is equipped with a webserver that can be accessed remotely and will mirror the touch panel visuals.

The panel also offers data backup to SD card and cloud (optional).

The PLC also allows remote shutdown of the storage and parts of it.

The internal storage area is monitored by an IP camera with local/remote recording and remote access via the WWW.

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Service

Depending on the size and use, Amvolt Battery Containers require regular revisions. Depending on the type of storage and the agreement with the customer, the customer himself or Amvolt provides it through its partners.

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Safety and Certification

A fundamental legislative requirement for batteries is battery certification. Typically, lithium cell-based energy storage systems are assessed against the IEC 62619 standard, which can be done in a variety of ways, from a simple issue of a conformity certificate to an actual technical assessment in an accredited test facility. It all depends on regional requirements.

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