Yes!
All Li-ion cells and packs shipped must be tested to meet the Recommendations on the Transport of Dangerous Goods on lithium-ion batteries for air shipment, rules set by the United Nations (UN).
The electrical test stresses the battery by applying high heat, followed by a forced charge, abnormal discharge and an electrical short.
During the mechanical test the battery is crush-tested and exposed to high impact, shock and vibration.
The UN Transport test also requires altitude, thermal stability, vibration, shock, short circuit and overcharge checks.
The section 38.3 of the UN Manual of Tests and Criteria (UN Transportation Testing) specify the following tests:

T1 – Altitude Simulation 

T2 – Thermal Test 

T3 – Vibration
T4 – Shock

T5 – External Short Circuit
T6 – Impact

T7 – Overcharge 

T8 – Forced Discharge 


Genport tests all the designed battery packs according to UN 38.3.

Generating renewable electricity is an important way to reduce carbon dioxide (CO2) emissions and many countries are installing wind and solar power plants to help meet targets for cutting CO2. One drawback of these energy sources is their variability: the wind tends to blow intermittently and solar power is only available during the daytime. Hence renewable power plants either have to be over-engineered to take account of this lower capacity factor, or they must be supported by spinning reserve power stations, typically fast-response open-cycle gas turbines – which goes against the environmental aims of the projects.

Ideally, excess renewable energy generated during times of plenty can be stored for use during periods when sufficient electricity is not available. But storing this energy is a difficult task: batteries and similar technologies perform well over short timescales, but over periods of weeks or months a different approach is necessary. Energy storage in the form of hydrogen is one such possibility: excess electricity is fed into an electrolyser to split water into its constituent parts, oxygen and hydrogen. The hydrogen is then used in fuel cells to produce electricity when needed, releasing the stored energy back to the grid.

This process allows excess energy produced in solar power plants to be stored and used, instead of wasted. Increasing the utilisation of renewable power plants helps to maximise the return on investment and lower the cost of electricity. The need for spinning reserve is also reduced as these facilities now have stored energy which can be readily converted back to electricity when required. Hydrogen can also be produced in a number of ways from biomass, allowing for the integration of this energy source in a complete renewable energy system. The most efficient way to convert hydrogen back to electricity is via fuel cells. This is not confined to grid electricity: in certain cases the stored hydrogen can be diverted for sale as fuel to fuel cell electric vehicle owners.

Fuel cells and electrolysers are complementary technologies. An electrolyser cell is much like a fuel cell run in reverse, using electricity instead of producing it. Commercial electrolyser technology is widely available and includes both proton exchange membrane and alkaline electrolysers.

As pure hydrogen is the fuel produced in this scenario, any type of fuel cell can be used to convert this into electricity in stationary power generation. For fuel cell vehicles, the technology of choice is proton exchange membrane fuel cells (PEMFC).

GENPORT has designed a portable power source, based on the hybrid concept integrating solar photovoltaic panels with a PEM fuel cell system to temporary generate electric energy in any off grid remote contest, providing continuously peak and constant power without external fuel, thermal signature and noise

This is a configurable system, based on the following modules: a retractable photovoltaic primary source of energy, a PEM fuel cell a PEM electrolyzer and solid hydrogen storage system.

The result is an innovative system for rapid deployment with enough power capacity to fulfill the demand of small loads as tactical communication systems.

GenPort 300 Hybrid PEM Solar with a granted patent (nr.0001394308) is a unique example of zero impact power source suitable as APU for small yacht allowing ocean navigation as well as to temporary power emergency electromedical devices, in an area devastated by natural disaster.

There are many possible configuration of the energy flow among the primary PV energy generator, the PEMFC, the PEM electrolyzer and the load.

When the daylight is available, the retractable PV panel powers directly the load and exceeding energy charges the battery pack or is utilized to power the PEM electrolyzer to convert and storage additional energy in hydrogen; if the adsorption of energy exceeds the capacity of the expandable PV panel or in case of a power failure, the battery pack and the PEMFC can dynamically contribute to strike an energy balance with also the eventual contribution of an external hydrogen source (GenFuel).

G300 HPS concept is multifunctional, configurable; it produces electric energy, pure hydrogen, water, and ozone for water purification.

The heart of the Polymer Electrolyte Membrane Fuel Cell (PEMFC) is the Membrane Electrode Assembly (MEA), which consists of a proton exchange membrane (typically a perfluorosulfonated polymer) and two catalyst layers (i.e. anode and cathode). However, between the Bipolar Plate (BP) and the MEA it is common practice to insert a third component, the so-called Gas Diffusion Layer (GDL), which is now considered indispensable for the proper working of the FC. The GDL is a critical component in a PEM because it must carry reactant gases from the flow fields to the catalyst layer as well as electrons from the bipolar plate to the catalyst layer, while at same time has to remove reaction products (exhausted gases and water) from the catalyst layer and help take heat out of the MEA up to the cooling channels in the BP. Last but not least, it has to guarantee good contact between BP and MEA. So, among the many properties that are required for the GDL there are electronic and thermal conductivity, porosity, hydrophobicity to assist in water management, compressibility and elasticity.

At present, GDLs are constructed from porous carbon paper, or carbon cloth, with a thickness in the range of 100–300 µm. The gas diffusion layers are typically wet-proofed with a PTFE (Teflon) coating to ensure that pores do not become congested with liquid water; this positive contribution of the PTFE is usually counterbalanced by some drawbacks such as an increase in electrical resistance and thickness, together with an inhomogeneous coating distribution and the need of a thermal treatment to ensure the adhesion between PTFE and carbon substrate.

Both carbon paper and cloth are typically macroporous materials, but to improve water removal and gas permeability it is necessary to introduce micropores and this is accomplished by coating a thin Micro-Porous Layer (MPL) onto the GDL surface adjacent to the membrane; this coating also improves the smoothness of the GDL surface allowing a better contact with the catalytic layer. In addition to being microporous and to preserve high gas permeability, the MPL has to be quite hydrophobic to drive out water and electrically conductive. In this paper the PEM component obtained by coating the MPL onto the carbon cloth will be referred to as Gas Diffusion Medium (GDM), reserving the term GDL to the macroporous substrate made of woven carbon cloth.

The catalyst layer, which is in direct contact with the membrane and the GDM, is either applied to the membrane (Catalyst Coated Membrane, CCM) or to the MPL (the so-called Gas Diffusion Electrode, GDE). In either cases, the objective is to place the catalyst particles, typically platinum or platinum alloys, within close proximity of the membrane. In this work we will use CCMs only.

In commercialized products the MPL is almost universally made from dispersion of carbon black and PTFE particles in water in different concentrations. However, in the recent literature an increasing attention has been paid to nanocarbon-based materials to be used in the formulation of innovative PEM-FC components.

To improve thermal and electrical conductivity of GDL, Single walled carbon nanotubes free-standing membrane (CNTFSM) have been developed by the Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta” and tested into a LT-PEMFC.

Kannan et al. made GDLs using a new type of partially ordered graphitized nano-carbon black. They were fabricated with teflonized nonwoven carbon paper as a substrate coated with a MPL, whose hydrophobicity was enhanced by the use of the graphitized carbon black provided by a Teflon suspension. The robustness of the micro-porous layer was improved by combining the graphitized nano-carbon black with a fibrous nano-carbon. The fuel cell performance in terms of power density was excellent.

Soehn et al. fabricated two types of gas diffusion electrodes (GDE) with nanocarbon as structural component. In the first one carbon nanotubes were directly grown on the fiber surface of a traditional carbon cloth in a CVD process. The second GDL uses the buckypaper preparation technique which allows a flexible design of layer-type GDEs with tuneable properties (wetting behaviour, catalyst concentration) or gradient materials.

Minimizing catalyst load and maximizing catalyst utilization can be achieved using platinum supported on high surface area nanocarbon materials, such as carbon nanofibers, graphite nanofibers multi-wall carbon nanotubes, although the effective attachment of Pt nanoparticles onto CNTs, for instance, remains a challenging task.

A Fuel Cell is an electrochemical device that continuously converts the chemical energy of the fuel (hydrogen) and an oxidant to DC electrical energy, heat and other reaction product (water). This reaction occurs inside the Membrane Electrode Assembly (MEA), an electrolyte membrane sandwiched between two gas diffusion electrodes.

Proton Exchange Membrane Fuel Cells (PEMFCs) are suitable for stationary, transport and portable energy applications.

In hydrogen-based energy systems, Fuel Cells are the technology of choice to maximize the potential benefits in term of energy efficiency, improved energy security and zero-emission.

Three major criteria should to be considered to choose a portable power source. The weight of the system, the cost of the energy produced and type of the fuel are the key drivers.

Continue Reading »

Over 50% of failures for critical loads are due to the electrical supply and the hourly cost of downtime for the corresponding applications is generally very high. It is therefore vital for the modern economy, which is increasingly dependent on digital technologies, to solve the problems affecting the quality and the availability of the power supplied by the distribution system when it is intended for sensitive loads.

Digital equipment (computers, telecom systems, instruments, etc.) use microprocessors that operate at frequencies of several mega or even giga Hertz, i.e. they carry out millions or even billions of operations per second. A disturbance in the electrical supply lasting just a few milliseconds can affect thousands or millions of basic operations. The result may be malfunctions and loss of data with dangerous (e.g. airports, hospitals) or costlyconsequences (e.g. loss of production).

More than 35 years after they first appeared, Uninterruptible Power Systems (UPSs) now represent more than 95% of back up power interfaces sold and over 98% for sensitive IT and electronics applications. Acting as an interface between the mains and sensitive applications, UPSs supply the load with continuous, high quality electrical power regardless of the status of the mains.

UPSs deliver a dependable supply voltage free from all mains disturbances, within tolerances compatible with the requirements of sensitive electronic devices. UPS can also provide this dependable voltage independently by means of a power source (battery) which is generally sufficient to ensure the safety of individuals and the installation.

UPSs are currently made up of three main sub-assemblies :

• a rectifier-charger to transform the alternating current into direct current and charge the battery;
• a set of batteries (generally lead-acid type) enabling energy to be stored and instantly recovered as required over a 5 to 30 minutes period, or even more;
• a static converter to convert this direct voltage into an alternating voltage that is perfectly regulated and filtered in terms of voltage and/or frequency.

Use of Batteries lead-acid has several relevant limitation, health and environmental problem:

• Low energy density – poor weight-to-energy ratio limits
• Cannot be stored in a discharged condition
• Allows only a limited number of full discharge cycles – well suited for standby applications that require only occasional deep discharges.
• Lead content and electrolyte make the battery environmentally unfriendly.
• Transportation restrictions on flooded lead acid – there are environmental concerns regarding spillage.
• Thermal runaway can occur if improperly charged
• Elevated temperature reduces longevity

Due to these relevant problems, Fuel Cells are becoming the technology choice for Uninterruptible Power Systems (UPS),  and PEMFC are being taken up by end-users in the telecoms, utilities, IT and other industry sectors.

The potential to move into formal system implementation in the field is driven by the Total Cost of Ownership gains resulting from the substitution of batteries by fuel cells.

These gains can be very significant in areas where grids are unstable (Asia, Africa, India) but are still significant in Europe where grid networks are quite stable.

Power sources  like G300 HFC and G300 HPS are ideal substitute technologies to lead-acid based UPS.

Quick start up, no environmental and acoustic emission, reliability, shock resistance, light weight are key advantages enabling Genport power source to fully satisfy requirements of small portable UPS, utilized in field surgical hospitals, mobile army medical corps, yachts, tactical telecoms units.

Power, Current and Voltage profile of G300 HFC. Voltage is stable (not decreasing as battery) while current is dynamically changing following the load demand.

G300 HFC powers a mobile communication system

We are completing all the electrical and mechanical tests, aiming to certify our portable GP300 HFC system, in order to obtain the CE.

In particular, in recent weeks we have carried out with our generator GP300 HFC electromagnetic compatibility (EMC) and water immersion tests (see photos below).

EMC tests aim to detect any electromagnetic emission of the device and also include susceptibility testing of the generator to external magnetic fields.

Tests of deep immersion in water, instead, want to prove that the device is perfectly sealed and water-proof (think of all those nautical/sealing applications or GP300 HFC ‘s use in the marine environment).

Yesterday, it was the ideal day to test our portable generator in extreme conditions, with a storm coming. We launched the system in Como lake and we dipped it in water for several minutes.

GP300 HFC has fully maintained its isolation from water and when opened it was completely dry and ready to be turned!

xxx

Since June the 1^st, Genport has expanded and relocated at the Technology Park in Vimercate (MB), within an area of more than 300 square meters.

Vimercate Technology Park was founded in 2006 in a location with a great history, because of the existing Companies, buildings architecture and green around.

Along the time, the Park has always been a benchmark because of the leadership of the resident Companies.

These are our new address, phone and fax numbers:

GENPORT S.r.l.

Via Lecco, 61

20871 - Vimercate (MB)

Italy

R&D, Production:

Tel.: +39 039 63 96 501

Fax.: +39 039 63 96 502

Administration:

Tel.: +39 039 63 96 500

Fax.: +39 039 63 96 502

GenPort 300 Hybrid Fuel Cell is our innovative portable fuel cell system designed to maximize power density, reduce to zero noise, thermal signature, pollution, vibration and provide a constant, reliable source of power. It is based on PEMFC and Battery Technologies, designed as a versatile power source, for any lightweight, off-the-grid, high energy density application.

GP300 HFC can operate as Battery Charger (BC), Auxiliary Power Units (APU). Different fuels system can be used with it, such as compressed hydrogen, metal hydrides, chemical hydrides (GenFuel) supplied in cartridges; in alternative, in order to solve definitely logistic problems for the delivery of the fuel, GP300 HFC can be integrated into an off-grid renewable energy system.

The implementation phase of the generator has been completed, so that GP300 HFC is actually in the process to be industrialized.

By the end of July 2011 we will complete all the electrical and mechanical tests, which aim to certify GP300 HFC, in order to obtain the CE. Several units will be realized later for our partners.

In parallel with the system certification, several functional tests have already been made (up to temperatures of 40°C) and now we are about to launch a test program, designed to verify operation of the system even at subzero temperatures (up to -20°C). More than one year, GP300 HFC was subjected to an intensive test campaign to check the system’s compliance with the functional and environmental requirements. In particular, functional tests were performed with electro-medical devices and portable mobile telecommunication systems (see the picture below). All these tests will be completed in July, in conjunction with the system certification.

The tests to be applied to GP300 HFC are both electrical and mechanical.

Electrical ones include:

• electromagnetic compatibility: electromagnetic emission tests of the device and susceptibility testing of the generator to external magnetic fields;
• electrical safety tests to demonstrate compliance with standards and obtain CE marking.

Mechanical tests, instead, include:

• shock, vibrations and drop tests to examine the mechanical strength of the whole;
• compliance testing to IP66-67 degree of the case during transport.

We will keep you updated in the coming weeks, as individual tests will be carried out on GP300 HFC!

xxx

Today, the major battery systems are the rechargeable lead acid and the primary manganese dioxide-zinc: both have a long history and are at an advanced state of technical maturity.

The Lithium-Ion Battery (LIB), conceived and developed in Japan by Asahi Kasei Co. and first commercialized by Sony Co. in 1991, is poised to challenge these established systems as the demand for higher-performance battery systems continues.

Lithium has a low atomic number and a high electrode potential that results in significantly high energy density for the LIB compared to lead and zinc in the traditional batteries. However, the development of new high energy lithium systems has been neither simple nor easy. It has required a total system approach and the development of breakthrough technologies based on new anodes, cathodes and non-aqueous electrolytes to continue the steady improvement of high energy lithium battery systems.

The early rechargeable lithium cells were plagued with safety problems caused by the tendency of lithium metal anodes to form dendrites and powder deposits on recharging. The lithium metal rechargeable cells now are restricted mainly to small capacity coin cells.

Since lithium metal constituted a safety problem, attention shifted to the use of a lithium-intercalation material as an anode. H. Ikeda of Sanyo was the first to patent an intercalation material in an organic solvent such as graphite in his June 1981 Japanese Patent No. 1769661. Later, I. Kuribayashi and A. Yoshino developed a new cell design using an intercalation carbon anode and a LiCoO₂ cathode and filed patents worldwide. Using a pilot plant developed for rechargeable Li-MnO₂ cells, Sony Energytec Inc. began to produce commercial cells (called the Li-Ion Battery) based on the Asahi patents in 1991. They also introduced electronic circuitry to control the charge-discharge, the use of a current interrupt device to interrupt current flow on build-up of excessive internal cell pressure and the use of a “shut-down” polymer separator.

The name “Lithium-Ion” now is accepted by the battery community worldwide, although there is no lithium metal in the cell. However, very often lithium metal deposition occurs during charging with the graphite anode and it may cause the many troubles on the LIB. Both electrodes operated by intercalation of lithium ions into the structure of the active materials. AT Battery Co., a joint venture of Toshiba Battery Co. and Asahi Chemical Co., was the second to commercialize the technology using Asahi patent portfolio.

The early cylindrical 18650 cell LIBs (18 mm in diameter and 65.0 mm long) had a capacity of 800 mAh and an end-of-charge voltage of 4.1 V. The initial cells used hard-carbon anode materials, which had a capacity of about 200 mAh/g, and the LiCoO₂ had a capacity of nearly 130 mAh/g due to 4.1 V charging voltage. The early lithium-ion cells used a propylene carbonate-based electrolyte. However, energy density of LIB improved rapidly and increased on average by 10% per year and has approached 3.1 Ah in 2010. Responding to pressure from device manufactures, the cell capacity improved through engineering and the introduction of graphite anodes, improved LiCoO₂-based cathode materials and the introduction of electrolyte additives.

Other recent developments include the incorporation of a fire retardant, which retards the combustion of the solvent, and a new additive to improve the wetting of the separator. New electrolytes and/or additives also are under development.

Today, LIBs are used in very high volumes in low power applications, such as mobile phones, laptops, cameras and other consumer electronic products. They have many attractive performance advantages, which make them also ideal for higher power applications, such as automotive and standby power:

• High energy/power density (about 4 times better than lead acid) and potential for yet higher capacities (high cell voltage of 3.6 Volts means fewer cells and associated connections and electronics are needed for high voltage batteries, so that, for instance, one lithium cell can replace three NiCad or NiMH cells which have a cell voltage of only 1.2 Volts).
• Does not need prolonged priming when new; one regular charge is all that’s needed.
• Relatively low self-discharge (self-discharge is less than half that of nickel-based batteries and they can retain charge for up to ten years).
• Low Maintenance (no periodic discharge is needed and there is no memory).
• Specialty cells can provide very high current to applications such as power tools.
• No liquid electrolyte means they are immune from leaking.
• Very small batteries also available. Solid state chemistry can be printed on to ceramic or flexible substrates to form thin film batteries with unique properties.
• Low weight.
• Can be optimised for capacity or rate.
• Can be discharged at the 40C rate or more: the high discharge rate means that for automotive use the required cold cranking power or boost power for hybrid vehicles can be provided by a lower capacity battery.
• Fast charge possible.
• Can be deep cycled: the cell maintains a constant voltage for over 80% of its discharge curve. It thus delivers full power down to 80% DOD versus 50% for Lead acid. This means that in practice, for a given capacity, more of the stored energy is usable or that the battery will accept more starting attempts or boost power requests before becoming effectively discharged.
• Very high Coulombic efficiency (Capacity discharged over Capacity charged) of almost 100%: thus very little power is lost during the charge/discharge cycles.
• No memory effect and no reconditioning needed (as for nickel based batteries).
• Tolerates microcycles.
• Long cycle life: 1000 to 3000 deep cycles. Cycle life can be extended significantly by using protective circuits to limit the permissible DOD of the battery. This mitigates against the high initial costs of the battery.
• Variants of the basic cell chemistry allow the performance to be tuned for specific applications.
• Available in a wide range of cell constructions with capacities from less than 500 mAh to 1000 Ah from a large number (over 100) of suppliers world-wide.
• Flexible form factor (manufacturers are not bound by standard cell formats): with high volume, any reasonable size can be produced economically.

For high power applications, which require large high cost batteries, the price premium of lithium batteries over the older lead acid batteries becomes a significant factor, impeding widespread acceptance of the technology. This in turn has discouraged investment in high volume production facilities keeping prices high and has for some time discouraged take up of the new technology. This is gradually changing and lithium is also becoming cost competitive for high power applications.

Among the limitations of LIBs, we can cite:

• Requires protection circuit to maintain voltage and current within safe limits.
• Subject to aging, even if not in use (but storage in a cool place at 40% charge reduces the aging effect).
• Transportation restrictions (shipment of larger quantities may be subject to regulatory control); this restriction does not apply to personal carry-on batteries.
• Internal impedance higher than equivalent NiCads.
• Expensive to manufacture (about 40 percent higher in cost than nickel-cadmium).
• Not fully mature (metals and chemicals are changing on a continuing basis).
• Degrades at high temperatures and when discharged below 2 Volts.
• Capacity loss or thermal runaway when overcharged.
• Venting and possible thermal runaway when crushed.

Measurement of the state of charge of the cell is more complex than for most common cell chemistries: the state of charge is normally extrapolated from a simple measurement of the cell voltage, but the flat discharge characteristic of lithium cells, so desirable for applications, renders it unsuitable as a measure of the state of charge and other more costly techniques such as coulomb counting have to be employed.

Although lithium cell technology has been used in low power applications for some time now, there is still not a lot of field data available about long term performance in high power applications. Reliability predictions based on accelerated life testing however shows that the cycle life matches or exceeds that of the most common technologies currently in use.

These drawbacks are far out weighed by the advantages of lithium cells and are now being used in an ever widening range of applications.

In order to control battery performance and safety it is necessary to understand what needs to be controlled and why it needs controlling. This requires an in depth understanding of the fundamental cell chemistries, performance characteristics and battery failure modes, particularly lithium battery failures. The battery can not simply be treated as a black box.

The Battery Management Systems (BMSs) encompass not only the monitoring and protection of the battery, but also methods for keeping it ready to deliver full power when called upon and methods for prolonging its life. This includes everything from controlling the charging regime to planned maintenance. There are many varieties of BMS.

There are three main objectives common to all Battery Management Systems:

1. protect the cells or the battery from damage;
2. prolong the life of the battery;
3. maintain the battery in a state in which it can fulfil the functional requirements of the application for which it was specified.

To achieve these objectives, the BMS may incorporate one or more of the following functions: cell protection, charge control, demand management, SOC (State of Charge) determination, SOH (State of Health) determination, cell balancing, battery’s history, authentication and identification, communications between the battery and the charger or test equipment and many others.

The cell voltage used for charging LIB is typically 4.2 Volts (charging to 4.1 Volts will increase the cycle life but reduces the effective cell capacity by about 10%). Battery lasts longer with partial charges rather than full charges. They can not tolerate overcharging and hence should not be trickle charged. Fast chargers typically operate during the constant current charging phase only when the charging current is at a maximum. They switch off at the point when the constant voltage, reducing current phase, starts. At this point the battery will only be charged to about 70% of its capacity.

Rechargeable lithium cells are used in a wide range of consumer products, including cameras, camcorders, electric razors, toothbrushes, calculators, medical equipment, communications equipment, instruments, portable radios and TVs, pagers and PDA’s.

They are fast replacing Nickel Metal Hydride cells as the preferred power in mobile phones. Laptop computers almost exclusively use lithium batteries.

Now high power versions of up to 1000Ah capacity and more are becoming available for use in traction applications in electric and hybrid vehicles as well as for standby power.

The price of Lithium cells continues to fall as the technology gains more acceptance: the target price for high power cells is around 300 $/kWh, but cell makers are still quite some way from achieving that.

Although lithium secondary batteries may cost two or three times more than the cost of equivalent lead acid batteries and even more when the necessary battery management electronics are taken into account, this is more than compensated for by their longer cycle life, which may be five to ten times the life of lead acid batteries. Valid cost comparisons should therefore take into account the lifetime costs as well as the initial capital costs.

As society advances, a variety of new technologies, machines and systems have been developed and more efficient industrial operations have been adopted. The concern for global warming and a clean environment along with the development of advanced electric and hybrid vehicles may be served well by advanced LIB. This situation has resulted in increased demand for high-performance batteries and power generation and storage. At the same time, demand has increased for a cleaner environment and a more efficient energy production, coupled with low power consumption systems. In this context, the LIB has made and will continue to make significant contributions and advances.

In the pictures below, you can see, respectively, the charging characteristics and the CC/CV 3 cycles charge/discharge and temperature monitoring (at 1C and 23°C) of 18650 LIB packs.

GENPORT

GENPORT‘s activity in designing Li-Ion battery pack BMSs involves, among others, the acquisition of cell’s electrochemical data using an Arbin battery tester, the configuration and parametrization of the fuel gauge and protection the integrated circuit and the BMS PCB (Printed Circuit Board) final design.