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In the fast-evolving landscape of smart, digitalised factories and warehouses, the integration of mobile robots is pivotal for achieving efficiency, maximising throughput, ensuring safety, and minimising operating costs. This surge in automation, particularly with various mobile robots like AGVs and AMRs, underlines the critical role of an industry-leading robust battery pack. Alexander Battery Technologies provides 40 years of expertise and insights into the essential considerations and best practices for acquiring the right battery pack for mobile industrial robots.

Meeting the 24/7 Operational Demand

Mobile robots possess a distinct advantage, operating tirelessly without breaks. This perpetual functionality necessitates a dependable and durable battery pack capable of sustaining continuous output without premature failures or depletion of charge. To address these specific application requirements, a bespoke custom battery pack tailored to factors such as capacity, size, durability, peak power output, cycle life, and temperature tolerance is often indispensable.

Navigating Technical Trade-offs in Battery Specification

The abundance of lithium chemistries introduces a matrix of trade-offs that demand careful consideration. Parameters like energy density, peak power output, operating temperature, cycle life, nominal output voltage, and maximum charge rate vary across different chemistries. The selection of optimal trade-offs is contingent upon the specific application. For instance, smaller AGVs or AMRs, where battery size and weight are critical, may favour NMC cells for their high energy density. Conversely, larger lifting platforms may opt for LFP cells, prioritizing longer cycle life over energy density.

Beyond Chemistry: Features and Approvals Matter

The battery pack selection extends beyond chemistry to encompass features critical for efficient operation. Thermal management features play a pivotal role in dissipating heat efficiently, ensuring safe operating temperatures. Data can help manage a felt of AGV’s through the use of wireless connectivity integrated into advanced custom battery packs. Wireless connectivity such as Bluetooth & low energy radio can provide real-time data about charge status and temperature to efficiently manage your fleet.

Robot/AGV Battery pack

Upholding Quality and Reliability in Production

Once the chemistry and features are determined, the battery pack manufacturer initiates a design that undergoes rigorous testing and approval before entering production. Quality and reliability are not merely end-of-line considerations but integral to the entire manufacturing process. Starting with the selection of high-quality lithium cells from reputable manufacturers like Samsung, LG, and E-One Moli Energy, meticulous attention is paid to assembly details, particularly critical elements prone to failure, such as welds.

Alexander Battery Technologies emphasizes transparency by inviting customers to inspect manufacturing facilities, fostering confidence in the production process. Incorporating quality principles ensures swift validation and certification of battery packs, aligning with the stringent standards prevalent in industries like automotive.

Embracing a New Era of Mobile Robotic with Reliable Battery Solutions

The paradigm shift towards digitalized and smart manufacturing practices necessitates a substantial increase in mobile robot deployment. Ensuring uninterrupted 24/7 operations relies significantly on the reliability of the battery power supply. By meticulously selecting the right cell and battery specifications, designing with precision, and choosing a dependable pack manufacturer, industrial operators can ensure consistent and predictable performance throughout the robot’s operational life. The battery power supply emerges as a cornerstone, guaranteeing seamless operation and peak efficiency for a mobile robot in the new era of industrial automation.

This is only a small summary from a technical in-depth piece titled ‘How to procure the right battery pack for a mobile industrial robot’. If you would like to read the full in-depth article, please fill in the contact form below to receive it via email.

Long cycle life, high energy density and resistance to shock and vibration are common requirements in AGVs and other types of mobile robots. How do they affect the choice of chemistry, cell, and battery pack design?

Efficiency, maximisation of throughput, safety and operating cost reduction are the watchwords of today’s smart, digitalised factories and warehouses. To meet these business objectives, industrial companies are automating ever more processes, and deploying more robotic devices, particularly various types of mobile robots. These include devices such as automated guided vehicles (AGVs) used in materials handling and other applications, automated mobile robots (AMRs) for last-mile deliveries (see Figure 1), and frame climbers in automated warehouses.

One of the advantages of mobile robots in comparison to their human counterparts is the ability to continue working 24 hours a day without the need for breaks. But this calls for a portable battery power system that can maintain a continuous output, without running out of charge, or failing prematurely because of a fault or breakdown.

This highlights the importance of specifying a mobile robot’s battery pack the right way. In nearly all cases, a mobile robot will require a custom battery pack, to meet the application’s requirements for capacity, size, durability and ruggedness, peak power output, cycle life, temperature tolerance, and other factors. This means that choosing the right custom battery pack manufacturer is also a critical decision.

Lithium-based batteries have become the most common choice for new industrial batteries today, because of their high energy density and capacity, giving much longer run-time between charges than any other battery chemistry. In fact, many types of lithium chemistries may be used in battery cells, and the technology and production of battery cells and packs is constantly advancing, giving OEMs the benefit of improved specifications year-on-year.

So what is the latest best practice for battery pack specification, and what are the key considerations that mobile robot OEMs should be taking into account today when specifying the cell type, pack design, and quality criteria?

Fig. 1: AMRs are beginning to be used to replace human drivers for last-mile deliveries of packages to homes and offices.

Specifying a battery pack: balancing the technical trade-offs

The proliferation of lithium chemistries, and of the components such as battery charge controller ICs that support lithium battery packs, mean that a robot OEM can be faced with a complex set of trade-offs to consider. Cell chemistries such as NMC (lithium nickel manganese cobalt oxide), LFP (lithium iron phosphate), LTO (lithium titanate), LMO (lithium manganese oxide) and LCO (lithium cobalt oxide) vary on a range of parameters:

• Energy density, affecting the size and weight of the battery pack
• Maximum peak power output
• Maximum safe operating temperature and susceptibility to thermal runaway
• Cycle life
• Nominal output voltage
• Maximum charge rate

The decision about the best set of trade-offs needs to be made on an application-by-application basis. For instance, in a small AGV or AMR carrying light loads, the battery pack will typically make up a large proportion of the total robot’s weight and take up a large space relative to the robot’s enclosure: here, high energy density is a key requirement, to produce the smallest and lightest possible battery, a requirement that would generally call for the use of NMC cells.

On the other hand, in a large mobile lifting platform capable of shifting loads of as much as 1,000kg, the battery pack will make a negligible contribution to total size and weight. Here, energy density is of little importance, so the platform OEM could instead choose LFP cells: their energy density is at least one-third less than that of NMC, but cycle life is much longer – more than 2,000 cycles, compared to as few as 500-600 cycles in some NMC implementations. LFP cells also operate safely at much higher temperatures than NMC, easing the design requirement for thermal dissipation, thermal monitoring, and safety circuitry.

Cycle life and charge time are crucial parameters for many mobile robots: AGVs in a smart warehouse, for instance, might work 24/7 all year round. A typical configuration uses a removable battery pack, allowing the AGV to return to a charging point for the removal of a discharged pack and its replacement by a newly charged pack. In this case, packs are continually cycling through the charge/discharge process. In this case, the cells in the pack need to be able to withstand many charge cycles, and to withstand fast charging so that they are available for use quickly after removal from an AGV in a discharged state.

A reputable battery pack manufacturer will be able to provide detailed guidance about the these and every other performance attribute of each lithium chemistry, and to advise on the best choice for the OEM’s mobile robot application (see Figure 2).

Fig. 2: many custom battery packs for robots are assembled with 18650 (black) or 21700 (green) lithium cells. (Image in the public domain.)

Features and approvals: getting the battery pack specification right

The choice of chemistry is just the start of the process of procuring the right battery pack for a mobile robot.

The evaluation of a custom battery pack manufacturer will normally be centred on the questions of features and quality.

The pack manufacturer should support the robot OEM’s application with the appropriate set of capabilities and features. These could include:

Thermal management features – as they discharge, batteries generate waste heat, which needs to be dissipated to keep the pack at a safe operating temperature. Sophisticated designs use innovative cell array configurations to draw heat out efficiently, reducing or eliminating the need for a heat sink. This saves space, weight and cost. Equally, mobile robots that operate in a cold environment, such as a refrigerated warehouse, need to take account of the battery temperature: a lithium cell cannot normally be charged when it is colder than 0°C. This might require the use of active in-pack heating technology to raise cell temperature above 0°C in preparation for charging. In many applications, active heating is a better solution than depositing the pack in a space at room temperature, and waiting for it to draw heat from the ambient air.

Telematics – a factory operator can exercise control of a fleet of AGVs or other mobile robots more effectively if it has access to data about each battery pack’s state of charge and state of health. Advanced custom battery packs can include wireless connectivity such as a Bluetooth® Low Energy radio, configured to provide real-time data about charge status, battery temperature, and other key parameters.

Regulatory compliance and approvals – the regulatory framework in which a battery design is made will depend on the countries or regions in which the pack is intended to be used. Regulation is a fast-moving field on which the battery pack manufacturer should be able to provide up-to-date advice. For instance, changes to US regulations have tightened the compliance requirements for cells and battery packs in mobile robots such as AGVs, bringing them into line with the regulations applying to battery electric cars. A custom battery pack manufacturer’s design should provide a smooth path through testing, approval and certification for any part of the world in which the robot OEM intends to market its products.

Quality and reliability: how to evaluate the production process

After specifying the cell chemistry and the right set of features, the battery pack manufacturer will generate a pack design. When testing and approval of final prototypes have been completed, the pack will go into production. At this point, the OEM is at the mercy of the battery pack manufacturer – there is no second source for a custom battery pack.

So how is an OEM to assure itself of the quality of the battery pack that it has specified?

In battery pack manufacturing, quality is not a bolted-on feature, or a control process applied at the end of the production line: if quality is not built into the entire process from the start of its design, there will be shortcomings in the production units coming off the line.

Attention to quality starts with the choice of lithium cell: the world’s three largest manufacturers – Samsung, LG and E-One Moli Energy – test all cells for compliance with all relevant safety and compliance requirements. There is a unit cost premium to pay for the quality and safety of the best cells compared to cells from unbranded cell manufacturers, but this up-front cost is more than recovered in the longer lifetime and superior safety assurance of the more expensive cells.

Alexander Battery Technologies has secure supply arrangements with the three premier cell manufacturers, and its packs use cells only from them.
The application of quality principles should also be evident throughout the production process. In assembly, high-quality pack manufacturers will pay particular attention to the elements of the structure that are most prone to failure, such as welds: for instance, advanced optical inspection techniques should guarantee that welds exceed high minimum thresholds for size and integrity, ensuring that the pack’s electrical connections remain sound even when exposed to the extremes of shock or vibration specified in the application.

Some manufacturers will follow the practice that Alexander Battery Technologies has instituted, of inviting customers to inspect its manufacturing facilities in detail. Modern ERP (enterprise resource planning) software systems may also be used to enable the customer to perform unit-by-unit monitoring and inspection of production output of their packs.

High-quality design and production also support rapid, first-time-right validation and certification of battery packs according to industry standards (see Figure 3).

Battery pack production for a new era of mobile robotics

The advance of digitalised and smart manufacturing and warehousing practices is leading to a rapid increase in the number and variety of mobile robots deployed in industrial settings. Operators rely on these robots to maintain unbroken operation 24/7; unforecast downtime severely impairs throughput and efficiency.

The battery power supply can be as reliable as any other component of a mobile robot: the guidance above shows how careful attention to cell and battery specification, design and production, and the choice of a dependable pack manufacturer, can ensure reliable and predictable performance for the life of the robot.

The rise of warehouse Automated Guided Vehicles (AGVs) has been facilitated by advancements in battery technology. The advancement in battery technology has led to increased efficiency of the AGVs that power an OEMs (original equipment manufacturers) warehouse. The adoption of AGVs from OEMs starts with the role the battery plays, ending with OEMs seeing costs lowered and efficiency raised.

The battery pack; the heart of the AGV

It is no exaggeration to say that the battery pack is the heart of the AGV, without the battery the AGV doesn’t function. This is why companies spend millions perfecting the battery pack that will go into their AGV, the better the battery pack, the better their AGV will be able to achieve its primary purpose. The battery packs provide the power needed to drive the AGV’s motors, sensors, and other components.

Our engineers can design the perfect battery for your automated guided vehicle to perform its task, a key design decision is always the power storage capability of the battery pack. The power storage system in the battery pack is what allows the AGVs to operate continuously in warehouse environments. An OEM may want their AGVs to operate for a long time between charges, therefore we would design the battery pack to have high power storage capabilities.

How can they be engineered to have optimal performance

Our expert engineers can design your pack with a smart BMS (battery management system) to enable your pack to be fast charging. This system will enable rapid battery replenishment during short breaks or between tasks, minimising your guided vehicles downtime. This ensures that your guided vehicle is available for as much of their working hours as possible. Alongside fast charging capabilities, our engineers can use energy-dense cells to formulate your pack. This reduces the frequency of recharging, thus maximizing the AGV’s productivity to provide greater results for OEMs.

The battery packs is attributed as a significant portion of the AGV’s weight, therefore it’s crucial the pack is as light as possible to allow the battery pack to perform efficiently. A lighter design will help optimise the guided vehicles payload capacity. Our engineers have had experience designing ultra-lightweight packs whilst still being in a suitably robust casing. To ensure your battery pack is maintained properly, an integrated BMS can monitor and manage battery health, charge, cycles and temperature. These additions can help ensure the battery packs longevity and health.

Robotics and AGV

Benefits for the OEM

OEMs that make the switch to AGVs will gain a competitive advantage over their competitors due to the increased efficiency provided by an automated fleet. Although there is an initial large outgoing expense, the return on investment (ROI) will be ongoing due to the lengthy usage amount you will obtain from AGVs. This long-term ROI will be seen through increased levels of efficiency they will bring to any OEM.

Here are some of the benefits of an Automated guided vehicle that will recoup an OEMs initial investment:

  • Increased efficiency with 24/7 capabilities with the correct battery pack design
  • Greater consistency and accuracy due to the precise paths AGVs are placed on
  • Flexibility of tasks, with an ultra-lightweight battery pack an AGV can handle both heavy and light payloads with the same efficiency.
  • Cost savings through eliminating the need to pay for human manual labor

At Alexander Battery Technologies we know that AGVs are the future of warehousing. With the battery pack itself being one of the most crucial aspects of the AGV, battery packs play a huge role in the advancement of warehouse logistics. We have 40 years of experience designing bespoke battery packs for all applications . We want to help you get ahead of your competition by designing and manufacturing your perfect AGV battery pack. If you want to know more on how we can help your AGV battery project, please contact us.

Yes, you should. We are having discussions with large OEMs, many having the same question. Is now the right time to electrify our product range?
With battery power being the power source for the future due to upcoming legislation, there has never been a better time to discuss your electrification needs.
The sudden spike in E-mobility interest from OEMs, has been accelerated by the government’s efforts to reduce their carbon footprint. These OEMs are achieving this through the process of electrification, which is the practice of replacing technologies that use traditional fuels with electric power.

How do governments affect electrification?

With the UK government targeting net zero by 2050, incentives for consumers and businesses are already in place.
Some of these incentives are;

  • EV owners not paying road tax on their vehicles
  • tax relief on low-emission cars for business use
  • interest-free loans of up to £100,000 for Scottish businesses looking to go green

Furthermore, the UK government announced that sales of new petrol and diesel cars and vans will be banned from 2030. This has led to funding to build 1000s of EV charging points to cope with the infrastructure that will need to be in place to make this efficient. These incentives and impending laws have seen a 60% YoY growth for E-mobility sales in the UK, with a target set for 22% of new manufacturer sales to be electric in 2024.

What does this mean for OEMs?

Vehicle OEMs need to decide their production schedules years in advance. With current and future government incentives pushing consumers and businesses toward Electric Vehicles, OEMs need to consider electrifying their range to meet an ever-rising level of demand. The current rate of reducing carbon emissions will not achieve net zero for the UK by 2050, making further incentives increasingly likely to encourage the demand for electric vehicles before new laws in 2030 come into place.

Is now the time to electrify?

There has never been a better time for OEMs to electrify their ranges. With the increased desire for consumers and businesses to switch to battery power, there has been a significant investment in battery technology globally seen from; Jaguar Land Rover, Recharge Industries and our very own Battery Technology Centre. This increased level of investment has led to improvements in the quality of batteries produced.

What this means for you is that your fleet of electric vehicles will start with a high-quality battery pack that will only improve as newer models are added to your range. With our 12 research and development labs open and operational, we produce battery packs with increased energy density, allowing for increased range on your vehicle. We are also working on designs and materials that will enable your battery pack to have faster charging times without hindering the overall life span of the battery pack. This results in increasing quality and consumers’ willingness to buy your product and continue to buy different products you offer when they want to upgrade.

Should you electrify your application?

Yes, we believe so for two significant reasons:

  • With new government regulations banning new petrol and diesel car sales from 2030, OEMs should be future-proofing so they are as prepared for these regulations as possible. An OEM can develop a strong relationship with a battery pack manufacturer to have the best battery pack in preparation for the all-electric swap.
  • With the quality of battery packs improving, finding a battery partner you have a good working relationship with is beneficial to an OEMs applications. Once a strong relationship is established, your battery partner will integrate new developments into your pack seamlessly due to understanding what the OEM is looking for in their pack.

If you are electrifying your existing applications or developing a new range of electric applications, click here to fill out our contact form to see how we with your electrification process.

With the increasing costs associated with running a business escalating, companies are increasingly turning to their supply chains to identify ways of cutting costs and improving efficiency. Reshoring refers to a company transferring operations from overseas locations back into the country of origin. Alexander Battery Technologies have identified eight key factors that we believe determine the decision of a manufacturer to reshore that fall into either push or pull factors.

Push Factors

Rising labour costs:

Perhaps the biggest factor in increased production costs, labour rates have seen massive increases since the original Chinese manufacturing boom. The cause of this has been a large increase in the number of skilled workers in the country, enabling the factories to have more advanced machines to complement their increasingly complex manufacturing processes. We have had conversations with OEMs that realise Chinese manufacturing is no longer the low-cost approach and have planned to reshore their manufacturing.

Quality control concerns:

OEMs have found managing quality concerns caused by overseas manufacturing extremely challenging. These issues can be difficult to manage and tough to amend. OEMs that reshore have the benefit of increased control over their supply chain due to the proximity of HQ and manufacturing operations.

Supply chain disruptions:

Supply chain disruptions cause unexpected costs for businesses. In a world where consumers want products fast, supply chain disruptions can be a nightmare for OEMs. The recent Suez Canal blockage cost an estimated $400 million an hour, with companies having their products in an unavoidable delay in deliveries. OEMs that have reshored a massive advantage compared to any of their competition that hasn’t made that step.

Political reasons:

Political instability can be a factor for companies to reshore to a more familiar political climate. With Covid still an issue in China, the risk of a lockdown is ever-present. As a result, products crucial to an OEMs supply chain have an increased risk of being delayed. A more familiar political climate provides a predictable environment for OEMs to operate.

Pull Factors

Proximity to market:

In some cases, reshoring manufacturing will enable an OEM to be closer to its target market, significantly reducing the lead times associated with the shipment of goods. With this, there will also be a significant reduction in shipping costs, which along with shorter delivery times, can give an OEM an advantage over their competition.

Enhanced control and flexibility:

With shorter lead times, OEMs can respond quickly to changing market conditions, allowing them to bring any additional optimisation features to the market quicker because of having locally based operations. Companies that have already reshored also can be agile and meet any unexpected, immediate demand for their product due to their shorter lead times.

Skilled workforce availability:

A driving factor for OEMs to reshore is access to a highly skilled workforce. OEMs looking to reshore to the UK with Alexander Battery Technologies will have access to highly skilled workers who have many years of relevant industry experience throughout the company.

Government incentives:

Governments often provide incentives to OEMs looking to reshore due to the economic benefits it will provide the country. These can include; subsidies, tax breaks, or other financial incentives that make the idea of reshoring more attractive for the business. Despite the logistical challenges of reshoring, OEMs can gain a significant long-term advantage over their competitors.

Alexander Battery Technologies is helping businesses reshore their manufacturing, and we would like to help you do the same. If you would like our help in reshoring your manufacturing or need a knowledgeable battery pack manufacturer, please complete the contact us form.

Choosing the right battery partner is essential to the long-term success of any battery-powered product. Having spent months & years designing the perfect product, the final piece that ties everything together is the power source. We believe there are a number of important factors to consider when selecting the perfect partner to power your product.

Quality

In order to maintain the long-term performance of your product it is important to have a high-quality power source at the heart of it. At Alexander Battery Technologies we have a number of measures in place to ensure we only produce high-quality products. These quality measures we have in place start with the operatives who will be assembling your products. Each operative that is on our production floor has had, at a minimum, two weeks’ worth of training before they work on live products. We do this to ensure that each of our production operatives is trained to a high standard to reduce waste and the potential for product defects as a result of human error. This has resulted in a 3.4 parts per million rate.

At Alexander Battery Technologies we use a FMEA (Failure Mode and Effect Analysis) to allow us to take a proactive approach in identifying any potential failure modes and asses the effect it will have on our products and our customers. This will benefit our customers by minimising the risks of any potential failure modes, leading to increased productivity, increase in OTIF which ultimately leads to increased satisfaction.

To ensure that the finished products we ship to our customers are a high standard, we conduct end-of-line tests that are designed to pinpoint any imperfections that have occurred during the manufacturing process. These procedures are performed in labs that have had their capabilities assessed and certified. To continue reading about our testing procedures please click here.

Geography

Part of Alexander Battery Technologies 5-year plan is to be closer to our customers. To take steps towards this, the business is currently working towards establishing a sales base in Germany and from there plan to establish a manufacturing facility within the EU. This move will aim to reduce the distance the finished product will need to travel. In turn, this will not only decrease cost associated with moving product but will also allow our customers to have their battery pack sooner in order to get their product to market quicker.

Reliability

This aspect of your decision not only takes into account the reliability of your eventual product but also the reliability of the supplier to deliver your product on time. An unreliable supplier could lead to both delaying your product’s entry into the market and cause performance issues well into its product lifecycle. We are proud of are on-time delivery rate, sitting at a 98% on-time delivery rate. We ensure that we deliver our products in a way that will not cause knock-on issues for our customer.

As a business we currently sit at 3.4 parts per million, this is in part due to our supplier approval process. All of our Cat A suppliers will complete ISO:9001 or ISO:13485, they will also sign up to our supplier quality plan and finally, complete a supplier questionnaire. On top of this, each part received at our inwards good station is checked to ensure they meet our quality standards. Each batch will then be given a batch reference which allows traceability. If there is a part that doesn’t meet our quality standards the part is identified and then placed in the suspect material bay with corrective action procedures to follow.

Technical

It is important that whoever takes on your battery project has the technical knowledge and experience to achieve your goals. Every project has a dedicated project manager who will not only communicate with the customer, they will also converse with each department to ensure the best product is delivered. The team will use their technical knowledge and expertise to keep up with the latest trends and apply that to your battery pack throughout the course of your project. The technical knowledge that Alexander Battery Technologies has is backed by 40 years of battery manufacturing experience.

In summary, when choosing a battery partner to power your product, there are several important factors to consider. Quality is essential to maintain the long-term performance of your product, and Alexander Battery Technologies has several measures in place to ensure high-quality products. Geography is also important to limit lead times and to reduce overall costs of the project. Reliability is crucial to the overall success of a project whether its delivery times or product reliability. Finally, having technical expertise for any supplier is needed to successfully deliver on all of the aspects wanted by the customer.

If your battery partner is not providing all of these aspects this may affect the performance of your product when it comes to market. If you want to learn more on how Alexander Battery Technologies is able to help you with all of these aspects, please visit our contact us page.

Heat management is an important part of maintaining a batteries peak performance in any battery pack. When we’re prototyping your custom battery pack it is important to identify how we can passively or actively manage the temperature of the battery. Our engineers will decide what actions they will take to effectively manage heat in your custom battery pack. This all depends on how your custom battery pack will be used and where it will be used.

Why do large format batteries face heat management problems?

Before we create a large format battery pack, we must understand why a large battery pack could face heat management issues. Once we have an understanding of why, we can then develop solutions in order to prevent them. In some cases, the thermal mass of a battery pack will be the reason why it faces heat management issues. A typical lithium-ion battery generally specifies 0.2C – 0.5C for charging. At this slow charge rate most lithium-ion cells do not generate a great deal of heat. However, once a battery requires a charging rate of 1C or above then the thermal mass of the pack will increase causing difficulties heating up or cooling down. Once a battery achieves these charging rates, heat generated becomes a critical part of the whole process.

Where does this heat come from?

Once we have understood why the batteries face heat management problems, its important to understand where the actual heat within the pack comes from. Li-ion cells typically have an internal resistance (IR) in the 80- to 100-mΩ range and are realistically heat sources when the charge or discharge current is near or exceeds the maximum for the cell. Both the Charge and discharge cycles of operation can and will generate significant heat through electrochemical reactions and IR. In basic terms Lithium Ions traveling from anode to cathode and vice versa during charge and discharge face resistance in the form of the separator, the chemical reaction through charging is endothermic (absorbs heat), the chemical reaction during discharge is exothermic (generates heat).

Why does the generated heat cause an issue?

The resultant heat generated can and often will remain inside the cells or pack, causing the cells to degrade faster than usual. The same can be said of discharging at above the specified rates indicated on the data sheets. Managing the heat effectively during charging helps reduce cells damage substantially. The acceptable temperature region for Lithium-ion batteries is normally −20 °C ~ 60 °C. Both low temperature and high temperature that are outside of this region will lead to degradation of performance and irreversible damages, such as lithium plating and thermal runaway. Alexander Battery Technologies can achieve effective heat management through proper prototyping, design and engineering of the battery. This will then lead to our batteries being both safe and reliable when used in their specified application.

How can we reduce the heat passively?

After initially discussing the specifications of your battery our engineers will apply the most effective method to reduce heat in your large battery pack. They will be able to choose from a number of methods to passively cool large format batteries, however these do tend to be application specific. Air cooling & heat sinks are a common method where there is sufficient airflow due to its simple operating system. Methods based upon the heat pipe principal, can be either refrigerant or water-based, these act in relation to both the principles of Phase change and thermal conductivity. Phase change materials combined with heat absorbent fillers can also be an effective passive BTMS (battery thermal management system). However, in real terms Air cooling is not sufficient to remove heat from a large-format lithium-ion battery.

How can we reduce heat actively?

Again, there are numerous ways for our engineers to actively cool large format batteries or large battery packs from forced air cooling to electrolyte immersion cooling. More commonly single cooing plate designs with polar mounted cells are used for both SESS (Static Energy Storage Systems) and EV (Electric Vehicles) applications. Double cooling plates where cells are sandwiched between the two are less common but are a good alternative. Both are indirect fluid cooling systems and require additional components to circulate and in turn cool the coolant. The same methodology can be used with refrigerant gasses but again external components are generally required and systems can become very complicated with external heat exchangers, pumps and delivery systems. Direct liquid cooling systems where the coolant is in direct contact with the cell, generally use electrolyte or oils to transfer heat away, these systems are similar if not more complicated than the indirect variant, heavy and bulky.

What are the best methods?

Air is by far the simplest method either by ducting external air into the battery or relying on simple convection and managing the loading on the battery. However ambient air doesn’t remain a constant temperature and if the air temperature increases above the battery temperature you are effectively heating the battery therefore the risk of overheating increases especially in high-power applications.

Liquid cooling is the most common method in EV however this is more complicated than air cooling requiring more components and control. There is also the consideration of how then the fluid is cooled either passively or actively, passively you face similar issues to air cooing, actively the system becomes even more complicated. In static ESS systems, indirect liquid cooling is also a popular option whereby the cooling can be provided by adiabatic chilled water systems that are essentially free cooling to control the temperature.

Immersion cooling again whereby the fluid is in direct contact with the cells is an effective way to cool large format batteries, some would say it is the best method overall but this method has its downsides, firstly it is expensive, it adds weight and has a heat capacity if we start to get into circulating the cooling fluid and/or cooing this actively then we get into very expensive and complicated systems.

Our commitment to our customers

At Alexander Battery Technologies our engineers keep their finger on the pulse in respect of new developments in heat management of high-power battery systems, we work closely with our customers in determining the right solution for the application, technology is advancing rapidly and with new development printed electronics thin film heaters combined with temperature and pressure sensors means that we can offer our customer’s the best solution for their application.

Conclusion

Heat management is crucial when it comes to keeping the battery pack working at optimal capacity for the duration required. Our highly skilled engineers have a variety of both active and passive methods to keep your batteries heat in control no matter what environment or charging state, this is why many companies chose to develop their own bespoke custom battery packs. If you wish to get in touch with us about developing your own custom battery pack, please contact us.

Over the last few years within the battery supply chain, companies have been discussing the idea of only paying for the energy used and not ever actually owning the battery pack itself and all of the costs and responsibilities that come with it. In the last 12-18 months though I’ve seen a huge spike in discussions around this business model and how it could work. Typically, it’s known as Battery as a Service (Baas).

So, what exactly is Battery as a Service, how does it work and why might it be a good idea (or not) for your business?

Battery-as-a-Service (BaaS) is an innovative business model that provides energy storage systems to customers in the form of a lease or subscription, rather than selling them outright. This new approach to energy storage provides several benefits to customers, which include cost savings, flexibility, scalability, access to the latest technology, expertise, and environmental benefits.

One of the key benefits of BaaS is the cost savings it provides to customers. The upfront investment required to purchase a battery system can be substantial, but with BaaS, customers can reduce capital expenses by paying for the battery system on a lease or subscription basis. This allows customers to save money and allocate resources to other areas of their business.

In addition to cost savings, BaaS also offers flexibility to customers. With flexible payment options, customers can adjust their energy storage capacity as their needs change over time. This means that customers can increase or decrease the size of their energy storage system as needed, without having to make a large upfront investment.

BaaS is also scalable, which is another major benefit for customers. As energy requirements evolve over time, customers can easily scale up or down their energy storage capacity without having to make additional capital investments. This scalability is important for customers who need to adjust their energy storage needs as their business grows or changes.

Another major benefit of BaaS is the access to the latest battery technology. BaaS providers offer the latest advancements in energy storage technology, which means that customers can benefit from the latest and greatest innovations in the field. This is particularly important for customers who are looking to stay ahead of the curve in terms of energy storage technology.

BaaS providers also offer expertise and maintenance services, taking these responsibilities off the customer’s plate. Customers can rest assured that their battery system is being managed and maintained by experts, which means that they can focus on other aspects of their business. This is especially important for customers who may not have the technical expertise to manage their own battery system.

Finally, BaaS provides environmental benefits. By providing a sustainable energy storage solution, BaaS enables customers to reduce their carbon footprint and contribute to a cleaner energy future. This is important for customers who are looking to be more environmentally responsible and make a positive impact on the world.

In conclusion then, Battery-as-a-Service (BaaS) is an innovative business model that provides numerous benefits to customers. From cost savings, flexibility, scalability, access to the latest technology, expertise, and environmental benefits, BaaS is an attractive option for customers who are looking for a more efficient and effective way to store energy.

So why isn’t everyone doing this then?

While BaaS provides numerous benefits, there are also several drawbacks that customers and service providers must consider.

One of the drawbacks of BaaS for customers is dependence on the service provider. By relying on the service provider for the maintenance and management of the battery system, customers may limit their flexibility and control over their energy storage. This dependence can also make it difficult for customers to switch to a different service provider if they are dissatisfied with the service they are receiving.

For service providers, one of the main challenges of BaaS is navigating the complex regulatory environment for energy storage systems. Service providers may struggle to effectively offer the service due to the regulatory hurdles they face.

Another drawback of BaaS for both customers and service providers is the limited availability of the service. BaaS may not be available in certain geographic regions or for certain types of energy storage systems, which can limit the options available to customers and the potential market for service providers.

In addition, the cost of providing BaaS can be high, both for service providers in terms of equipment and maintenance and for customers in terms of ongoing expenses. This can make the BaaS model less attractive for both parties, especially if alternative energy storage solutions are available at a lower cost.

Battery degradation is another major drawback of BaaS. Batteries have a limited lifespan and will degrade over time, which can impact the performance of the energy storage system and the financial viability of the BaaS model.

For customers, a long-term commitment to the BaaS model may also be a drawback. By making a long-term commitment, customers may limit their flexibility and options in the future. This can be particularly problematic if they need to change their energy storage needs over time.

Finally, service providers may face competition from other providers offering similar services. This competition can impact their ability to attract and retain customers, making it difficult for them to succeed in the BaaS market.

In conclusion, while BaaS provides numerous benefits to customers and service providers, there are also several drawbacks to consider. Dependence on the service provider, complex regulations, limited availability, high costs, battery degradation, long-term commitment, and competition are all factors that must be considered when evaluating the BaaS model.

At Alexander Battery Technologies, we believe that a strong commercial partnership, coupled with long-term reliable demand are the two key enablers for initiating a successful BaaS business model together. In some markets, consortiums between several customers, several battery manufacturers, or both could make a BaaS model more attractive and more accessible on both sides. If the business on both sides has genuine value, the hurdles of up-front design and engineering costs can be easily overcome by a mid- to long-term volume commitment or supply contract and straightforward commercial discussions.

What do you think? Is BaaS something your business is interested in? Do you see other hurdles or additional benefits not covered here?

Contact us today for all of your custom battery pack manufacturing needs!

From our 40 years of custom battery manufacturing experience, we know that selecting the correct welding technique for the job is crucial to the success of the product. We hope that by the time you finish this article you will understand why we use a certain battery welding technique for each of our battery packs.

Resistance welding

Alexander battery technologies has been using Resistance welding in various guises for nearly 40 years since the technology became mainstream. Whilst we have used various equipment from AC/DC power supplies to capacitor discharge equipment, our latest linear equipment has really improved our control of the process for battery welding; High Duty DC inverter power supplies with advanced closed-loop electrical modes and integrated database process control and data logging help us determine the best settings for the application.

Resistance welding is well known as the most cost-effective method for joining tabs on a wide range of cell types and sizes. It’s a cost-effective choice for welding nickel tab material up to 0.3mm thickness, and nickel or copper clad steel tab material to around 0.2mm, which is suitable for a wide range of requirements.

Resistance welding is normally used for low to medium current applications that consist of cylindrical or small prismatic cells, typically up to 20 -30A current rates depending upon the application, such as small handheld devices, small modules etc.

Resistance welding can be easily automated for extreme high-volume manufacturing but more commonly used in a semi-automatic environment.

Micro TIG (Tungsten Inert Gas Welding)

Micro TIG (Tungsten Inert Gas Welding), also known as pulsed arc welding, is our preferred method for challenging nonferrous, dissimilar material welding applications. Majority of cylindrical cell casings are manufactured from nickel plated cold rolled steel which is chemically compatible with copper making M-Tig the perfect choice for us.

M-TIG welding utilises a high frequency power supply, providing low current control and arc stability, this enables very fine welding and is useful for copper to cell joining. This makes it a good solution for buss bar welding that cannot be handled by resistance welding or would normally require a large power laser welder, various welds are possible up to and beyond the thickness of 0.5mm of pure copper.

Micro TIG is normally used when we require to weld low-impedance copper cell jointing plates for medium to high current applications again consisting of small to large cylindrical cells (30-200A) where low resistance is required for heat management.

We currently run the machines semi-automatic with pneumatic actuation, however we expect to automate this in the future. Happily, this can be easily automated by adding either an X/Y cartesian system or six axis robots for a more repeatable process on larger modules.

Laser welding

Although the technology has been around since the 80s, laser welding for batteries is still relatively new. Uptake is growing especially in the EV space.

Two laser types are a good choice for battery applications: pulsed Nd:YAG (neodymium-doped yttrium aluminium garnet, Nd:Y3Al5O12) and Fibre in three flavours (continuous wave (CW), Quasi continuous wave (QCW) & Nanosecond (NS) offering high speed repeatable welding and wealth of SPC and data gathering.

The most commonly used today generally being fibre in one flavour or another, the Nd:YAG laser still has its place for precision spot welding or sealing cell cans with minimum heat however, CW or modulated wavelength fibre is the sound choice for fine focus in battery pack manufacture, laser welding can be used for joining busbars to cells and tabs to busbars, laser welding provides a high degree of flexibility, welding both thin and thick tab materials, varied materials such as copper, aluminium, steel, and nickel, as well as some dissimilar material combinations. Welding tabs or terminal connections.

It is recommended that laser is the joining technology choice in any application with current requirements greater than 200A for long durations such as large prismatic packs, ESS, LEV & EV, also where noise, vibration, and harshness (NVH) is a consideration.

Ultrasonic welding

This method uses high-frequency ultrasonic vibration, normally around 20kHz , to join materials by creating solid state bonds when clamped. The frequency vibrations like those used for joining or melting plastics create shearing and plastic-like deformation between the metal surfaces. Combined together with a high clamping force this produces an atomic level bond.

The challenge in some cases here is that the clamping needs access from both sides of the join, with a sonotrode – which creates the ultrasonic vibrations – on one side and an anvil on the other. This works by passing the ultrasonic energy through the join in a highly focused area or areas. Ultrasonic welding can be used for multiple thin foils, dissimilar materials, or highly conductive materials such as aluminium or copper.

Ultrasonic welding is primarily used for flexible busbars and joining of pouch cells as the tabs are generally dissimilar metals and difficult to weld with other methods.

Wire bonding / ultrasonic wedge bonding

As the name implies this is another form of ultrasonic welding whereby the cell becomes the anvil and a thin wedge sonotrode provides the join, normally used with various thickness of wires for cylindrical cells, in some cases thin nickel or copper ribbon is used and in a prismatic pack can be used for the voltage sensing direct to PCB join.

This system is popular in EV and aerospace environments, however cell packaging must be robust for this application with noise, vibration and harshness taken into consideration.

To learn more about how Alexander Battery Technologies uses welding for each custom-made battery pack, contact us and we will be in touch with you.

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