From the smallest component through to building a Freedom Won (“FW”) containerised solution - with each step of the way, safety is paramount.

FW, an original equipment manufacturer, is compliant with industry best practices in terms of how to build and manage Battery Energy Storage Systems (BESS) with a safe environment and methodology.

In addition to these best practice guidelines, FW adheres to the ISO guidelines as set out in; ISO 9001: 2015, which is defined as the international standard that specifies requirements for a quality management system, ISO 14001: 2015, which specifies requirements for an effective environmental management system, and ISO 45001: 2018, which is the international standard for occupational health and safety.

We keep our employees safe as they design and assemble energy storage systems for home, business, commercial and industrial use – in turn contributing to a robust and safe renewable energy sector.

Every piece of the FW BESS is meticulously built with safety at the forefront of the design. Some of the components with advanced safety features are the LiFePO4 cells, BMS, copper busbars, wiring harnesses, circuit breakers, fuses, and the battery casing. FW also carefully selected and designed the packaging in which the batteries are transported.

The company’s principal range, the Freedom Won LiTE range, includes advanced safety features and has been leading the market with high-quality manufacturing, and industry-leading performance.

LiFePO4 Cells:

According to BCG Research, Lithium Iron Phosphate (LiFeP04) consistently performs better than most other chemistries in terms of safety and battery lifespan. In 2009, FW was one of the earliest companies to develop the use case for LiFeP04 chemistry in the stationary storage sector.

FW experimented with LiFePO4 from the outset after carefully considering multiple aspects of the technology, specifically relating to the company’s stringent safety standards. The company found a cell technology partner in China - the country holds about 90% of the world’s LiFePO4 manufacturing capabilities.

FW has ensured that all our technology and design comply with the IEC 62619:2022 standard, which specifies design safety requirements and tests for the safe operation of secondary (rechargeable) lithium cells and batteries used in industrial applications, including stationary applications. “These cells get put through extensive testing to ensure that they can handle being dropped, crushed, pierced with a sharp object or short-circuited without catching fire,” says Antony English, the company’s co-founder.

“We looked into all other chemistries that were available at the time (2009) and by far lithium iron phosphate was (is) the safest, because it doesn’t spontaneously ignite if the cells get too hot; and right up front we only considered developing our products with this technology,” says English.

Our lithium batteries should never be dropped, as this could cause internal damage. However, during research and development, samples of FW batteries are drop tested according to applicable specifications, including being dropped at different angles. All FW batteries that were put through the drop test have continued to function normally.

BMS is on the ball:

The FW Battery Management System (BMS) records the number of cycles that the battery has delivered. It also measures and controls the voltages of each cell, internal battery temperatures, battery current, and pack voltage. It is critical for lithium cells to operate within specified voltage and temperature ranges to avoid irreparable cell damage.

While monitoring all functions within the battery, the BMS controls external components of the system, such as the inverter (through the CAN bus interface) by limiting the charge current and voltage, while also ensuring that the battery’s temperature is at a safe operating level. If the battery overheats and/or the voltage is too high or too low, the BMS can automatically stop the charge or discharge.

The FW BMS’s unique features have been developed and perfected over 15 years. The BMS can also calculate internal resistance of the cells and report abnormal resistance of busbars and connectors, long before any safety issues arise.

The BMS always monitors all safety critical features within the battery and will prevent an unsafe situation by either shutting down external devices through CAN bus or, if necessary, shutting itself down completely.

Copper Nickel-plated busbars – efficiency and reliability in one:

The innovation does not stop there. FW specifically designed the busbars to be larger than the industry norm. The busbar size ensures that there is minimal resistance, no hotspots, or heat build-up when running at high power.

As an electrical current conductor, the copper busbars within a FW battery are highly efficient. More so than most other metal conductors.

Nickel plating ensures that there is no oxidation of the conductor surface, which eliminates the risk of high-resistance connections developing over time.

Wired right:

The power cables or busbars are fastened to the cells with heavy duty studs or through laser welding, to reduce the risk of a hot connection because of being inadequately fastened.

The FW high voltage battery range also has fuses in series with the cells at multiple locations inside the battery. In case of impact on the battery or other mechanical damage causing an internal short circuit, the fuses will blow to limit the risk of further damage or danger to persons. Fuse isolators also ensure safety during an assembly at the factory.

Up and down cycling:

The FW batteries are designed to manage two 80% Depth of Discharge (DoD) cycles per day. If those cycles are less than 80% DoD, a pro rata calculation comes into effect. If a battery discharges from 100% to 20% State of Charge (SoC) followed by a charge to 100% - that is a full warranty cycle. This is an important consideration with South Africa’s loadshedding, as the country moves through the different loadshedding stages. A stage whereby the load is shed 4 times a day would mean that the same battery must do 4 half cycles per day. Should the battery operate through more cycles in a day, the temperature might rise to maximum levels (a situation that would be controlled safely by the BMS).

The FW container builds have internal cooling and utilise other mechanisms such as extraction to prevent overheating. “We also have insulation on the walls and ceiling to help maintain the equipment at a reasonable temperature in hot environments.”

Also, to ensure battery temperatures are controlled properly, the larger FW Commercial models include forced air fan cooling in the casing.

Circuit breakers:

The integral circuit breaker can handle high external short circuit currents; it prevents potential fires and allows the BMS to disconnect at any moment if needed.

The circuit breaker is an important aspect of the battery in terms of safety, as it too can turn off a battery that is malfunctioning.

“It is definitely one of the main distinguishing features of the FW LiTE, because the range offers very high performance, with DC rated breakers that can handle significant currents, both overload currents, and short circuit currents,” he added.

As a result of this feature, the battery could short-circuit externally and suffer no damage at all.

Comparatively, most other batteries on the market rely on MOSFETS (large power transistors) for current control. The FW circuit breakers also allow the BMS to disconnect the battery from the DC bus if a connected device does not respond to the CAN bus commands that aim to avoid an overcharge or discharge event.

Other batteries in the same class as the FW LiTE range also use contactors and rely on internal fuses; however, the limitation is that the contactor can still be damaged by a short circuit current whereas a LiTE range battery is still usable after a trip on a short circuit.

The FW circuit breaker is resettable and allows for the battery to be used again after an overload or external short circuit without replacing fuses or MOSFET boards. 

The breaker, on all Home and Business models, is rated for a 36kA fault (short circuit) current. The system therefore in most cases does not require another external DC isolator or breaker between the battery and the inverter. -

Exterior Battery casing:

The primary goal of the casing design is to enclose the cells such that they cannot move or be easily damaged. The 3mm thick high-strength aluminium casings are coated in white powder coating and provide an ideal attractive and strong enclosure for the cells. The powder coating finish is also non-toxic and chemically inactive, to meet environmental protection standards. 

The packaging and handling:

The packaging within which the completed battery is transported includes a wood crate with foam inside to absorb impact that it might experience during transportation. The packaging combined with the casing design complies with UN38.3 requirements.

Some FW LiTE models can be manually lifted by two people and can be moved into position by their handles, however for larger models, a pallet jack or small crane is advised.

The industry:

Although individual companies have stringent standards in place, risks within the renewable energy sector should be mitigated by industry bodies.  The South African renewable energy industry has placed importance on meeting international standards and self-regulation, which has led to sustainable growth.

The three main safety risks in the solar or renewable energy sector would be related to electrical shock, potential fire from a defective installation, or falling accidents because of working from heights.

The development of larger companies in the sector has meant that the industry largely has a professional approach to installations and has grown to pay attention to training, skills development and meeting regulatory requirements.

FW puts as much thought into the training and development of its workforce as it does the development of the battery. Our assemblers are trained for 3 months before they work unsupervised. Insisting that every one of our manufacturing employees has an electrical qualification, means that the company’s employees have the required base knowledge to operate within a highly charged environment.

Freedom Won: Leading the Charge in Sustainable Energy Solutions, Driven by Safety and Innovation..