Related Topics:
Upgrade Your Razor Lithium-
How much graphite is suitable for lithium batteries
Most lithium-ion batteries contain approximately 10 to 20 grams of graphite per ampere-hour. This quantity is essential for maintaining effective ion transport during charging and discharging cycles.
FAQs about How much graphite is suitable for lithium batteries
How much graphite does a lithium ion battery need?
Commercial LIBs require 1 kg of graphite for every 1 kWh battery capacity, implying a demand 10–20 times higher than that of lithium . Since graphite does not undergo chemical reactions during LIBs use, its high carbon content facilitates relatively easy recycling and purification compared to graphite ore.
Why is graphite a good battery material?
Storage Capability: Graphite's layered structure allows lithium batteries to intercalate (slide between layers). This means that lithium ions from the battery's cathode move to the graphite anode and nestle between its layers when the battery charges. During discharge, these ions move back to the cathode, releasing energy in the process.
Why is graphite a key element in a lithium-ion battery cell?
As the largest critical element by volume in a lithium-ion battery cell, graphite is a key enabler when it comes to helping nations achieve their climate goals and de-risk their supply chains."
Is graphite suitable for battery supply chain?
Not all forms of natural graphite are suitable for entry into the battery supply chain. Credit: IEA (CC BY 4.0) Graphite—a key material in battery anodes—is witnessing a significant surge in demand, primarily driven by the electric vehicle (EV) industry and other battery applications.
Is graphite anode suitable for lithium-ion batteries?
Practical challenges and future directions in graphite anode summarized. Graphite has been a near-perfect and indisputable anode material in lithium-ion batteries, due to its high energy density, low embedded lithium potential, good stability, wide availability and cost-effectiveness.
What percentage of batteries use graphite?
Graphite for batteries currently accounts to only 5 percent of the global demand. Graphite comes in two forms: natural graphite from mines and synthetic graphite from petroleum coke. Both types are used for Li-ion anode material with 55 percent gravitating towards synthetic and the balance to natural graphite.
-
Energy Storage How to store lithium batteries
Lithium-ion batteries have become the backbone of our portable electronics and renewable energy systems. Their high energy density, low self-discharge rate, and lack of memory effect make them superior to many other battery types. However, these advanced features come with a caveat: lithium-ion batteries require. Now that we understand the key factors affecting lithium battery storage, let's explore some practical tips to implement these principles. These. Though lifepo4 batterieshold up better in the cold than many other battery types, it's still important to protect them from low temperatures as much as. Part of solar panel battery maintenance is monitoring your system. Since many households choose solar energy as a way to offset high energy prices, being able to monitor how much energy. When deciding where to store solar batteries, the primary considerations are safety, performance, and longevity. The question arises, "Is it safe.
[PDF Version]
FAQs about Energy Storage How to store lithium batteries
How do you store a lithium battery?
The best way to store lithium batteries is in a controlled environment. Keep batteries in a cool place, ideally between 20°C to 25°C (68°F to 77°F). Never store batteries in freezing conditions or extreme heat. Aim for a dry environment with relative humidity below 50%. Ensure proper air circulation in your storage area to prevent heat buildup.
How long can a lithium ion battery be stored?
The amount of time lithium-ion batteries can be safely stored depends on several factors, including the battery's charge level, temperature, and overall condition.
How do you keep a lithium ion battery healthy?
Exposing batteries to extreme temperatures: Avoid hot cars, unheated garages, or anywhere with temperature fluctuations. Ignoring the battery for months: It's essential to check the condition of your battery every few months. Properly storing your lithium-ion battery is one of the best ways to make sure it lasts a long time.
What temperature should a lithium battery be stored?
These batteries are sensitive to extreme conditions, both hot and cold. The ideal temperature range for lithium battery storage is 20°C to 25°C (68°F to 77°F). This temperature range helps to maintain the battery's chemical stability and avoids rapid aging. Avoid exposing batteries to direct sunlight or storing them near heat sources.
Can a lithium battery be stored in a garage?
Yes, you can store lithium batteries in the garage, but maintain proper airflow to decrease particulates in the air and keep the environment around the battery fresh. Installing screens or vents can maintain fresh air and prevent the battery from becoming excessively hot. How long can a lithium battery sit unused?
What is the optimal charge level for storing lithium-ion batteries?
The optimal charge level for storing lithium-ion batteries is between 40% and 60%. While it may seem counterintuitive, storing a lithium battery at full charge (100%) or fully discharged (0%) can cause stress and accelerate the degradation of the battery cells.
-
How much power soldering iron should be used to weld lithium batteries
Yes but very carefully and very quickly. Soldering Li-Ion batteries like 18650 and 21700cells puts a lot of excess heat into them during the soldering process. This extra heat does a small amount of damage to whatever cell it gets to. The longer a given cell or cells stays hot, the more capacity they will lose. If you are using a. Yes. When soldering lithium-ion batteries, the cell almost always gets damaged to some degree from the intense amount of heatemitted by the soldering iron. The only thing you can really do is. Soldering lithium-ion batteries is generally not recommended because the heat generated by soldering can damage the battery and potentially cause a fire. If the battery must be soldered, it should be done by a professional. Again, you really should not be soldering lithium-ion batteries unless your project has specific requirements for it as it can be dangerous to you and the. It takes a great amount of care and skill to solder lithium-ion batteries. You can't just learn how to do it on your first build. That is just not going to be.
[PDF Version]
FAQs about How much power soldering iron should be used to weld lithium batteries
Should I solder or spot welding lithium cells?
If you are new to building batteries or have not started building batteries just yet, then you may be wondering should I solder or spot welding lithium cells and which is best. Compared to soldering, spot welding will always be the easiest and most practical way to join lithium cells.
Can You solder a lithium battery with an electric iron?
Take the 18650 lithium battery as an example. Connecting three 18650 batteries in parallel and soldering with an electric iron will not explode, but your wrong method may cause safety hazards. ①The surface of 18650 cannot be directly soldered with an electric soldering iron.
Is a soldered lithium battery better than a welded battery?
A soldered lithium battery is much, much more difficult to build than a welded battery, but they are both equally as difficult to repair. This makes sense because both welding and soldering are inherently permanent processes. We hope this article helped you learn everything you needed to know about soldering vs spot welding lithium cells.
How much power do you need to solder a lithium battery?
To solder a lithium battery, you're going to need at least 100 watts of power at the tip. Having triple-digit watts at your disposal is required to be able to get in there, form an excellent connection, and get you- quick. It may seem counter-intuitive, but the best soldering iron-to-solder lithium-ion batteries is going to be the hottest one.
How to solder lithium batteries?
If you are going to solder lithium batteries, apply lots of flux to the cell before touching it with the soldering iron. This will ensure that the cell surface is in the best possible state to be soldered which will require less soldering time for a good connection. In this article, we will discuss how to solder lithium batteries.
Can a lithium battery be welded with a welder?
A larger battery needs more cells. More cells require more solder joints. More solder joints require more heat and provide more room for error. Other than the heat, the same is true for welding lithium cells, but it's a lot easier to make consistent connections with a welder compared to soldering.
-
How many degrees can lithium iron phosphate batteries withstand
LiFePO4 batteries can typically operate within a temperature range of -20°C to 60°C (-4°F to 140°F), but optimal performance is achieved between 0°C and 45°C (32°F and 113°F).
FAQs about How many degrees can lithium iron phosphate batteries withstand
What temperature does a lithium iron phosphate battery discharge?
At 0°F, lithium discharges at 70% of its normal rated capacity, while at the same temperature, an SLA will only discharge at 45% capacity. What are the Temperature Limits for a Lithium Iron Phosphate Battery? All batteries are manufactured to operate in a particular temperature range.
What temperature does a lithium battery operate?
All batteries are manufactured to operate in a particular temperature range. On the lithium side, we'll use our X2Power lithium batteries as an example. These batteries are built to perform between the temperatures of -4°F and 140°F. A standard SLA battery temperature range falls between 5°F and 140°F.
What is a lithium iron phosphate (LiFePO4) battery?
In the realm of energy storage, lithium iron phosphate (LiFePO4) batteries have emerged as a popular choice due to their high energy density, long cycle life, and enhanced safety features. One pivotal aspect that significantly impacts the performance and longevity of LiFePO4 batteries is their operating temperature range.
What temperature should A LiFePO4 battery be operated at?
LiFePO4 batteries can typically operate within a temperature range of -20°C to 60°C (-4°F to 140°F), but optimal performance is achieved between 0°C and 45°C (32°F and 113°F). It is essential to maintain the battery within its recommended temperature range to ensure optimal performance, safety, and longevity.
Are LiFePO4 batteries safe?
LiFePO4 batteries exhibit an ideal operating temperature range that ensures their optimal performance and longevity. This range encompasses both low and high temperature thresholds. Deviating from this range can have adverse effects on battery capacity, efficiency, and even safety.
Can A LiFePO4 battery be used in cold weather?
LiFePO4 lithium batteries have a discharge temperature range of -20°C to 60°C (-4°F to 140°F), allowing them to operate in very cold conditions without risk of damage. However, in freezing temperatures, you may notice a temporary reduction in capacity, which can make the battery appear to deplete faster than it does in warmer conditions.
-
How to open a factory to produce lithium batteries
This guide will give you a low down on all of the major steps involved, from choosing a legal structure to creating a financial forecast and registering your business.
FAQs about How to open a factory to produce lithium batteries
How to start a lithium-ion battery manufacturing business?
The procurement and management of raw materials is a critical component of establishing a successful lithium-ion battery manufacturing business. Lithium, cobalt, and graphite are the primary materials required for the production of lithium-ion batteries, and their availability and cost can significantly impact the overall startup expenses.
How to start a battery manufacturing business?
The next step to start your battery manufacturing business is to use market research to check that there is indeed an opportunity to be seized. Let's take a look at what this involves. In a nutshell, doing market research enables you to verify that there is a business opportunity for your company to seize, and to size the opportunity precisely.
How much does it cost to start a lithium-ion battery business?
In total, the facility setup and infrastructure development for EnergyPact Lithium Solutions' lithium-ion battery manufacturing business can account for a significant portion of the startup costs, ranging from $40 million to $190 million or more, depending on the scale and complexity of the operation.
How can research improve lithium-ion battery production?
Research efforts may also focus on improving the manufacturing processes and reducing the overall cost of lithium-ion battery production.
What is lithium ion battery production?
Lithium-ion Battery (LIB) production requires manufacturers to combine expertise from various disciplines, including chemistry, physics, and engineering; invest in production and R&D activities; and develop cell design competencies. These requirements create barriers against new entrants into this industry.
How do you finance a battery manufacturing business?
Financing your startup will probably require you to obtain a combination of equity and debt, which are the primary financial resources available to businesses. Equity refers to the amount of money invested in your battery manufacturing business by founders and investors and is key to starting a business.
-
How to calculate the output of energy storage lithium batteries
The formula Watts = Volts × Amps provides a straightforward way to calculate power in lithium battery systems. It works effectively because lithium batteries maintain consistent voltage levels during operation, unlike other battery types that experience significant voltage drops. Here's what you need to know: Voltage (V): Measured in. The capacity of a battery or accumulator is the amount of energy stored according to specific temperature, charge and discharge current value and time of charge or discharge.
-
How about lithium battery energy storage containers
Battery energy storage containers are becoming an increasingly popular solution in the energy storage sector due to their modularity, mobility, and ease of deployment. However, this design also faces challenges such as space constraints, complex thermal management, and stringent safety. In this rapidly evolving landscape, Battery Energy Storage Systems (BESS) have emerged as a pivotal technology, offering a reliable solution for storing energy and ensuring its availability when needed. Get it right, and you unlock reliable backup power, lower energy costs, and seamless integration with solar and wind. Efficient energy storage capability, 2. Long lifespan and reduced maintenance needs, 4.
-
Use of lithium batteries in solar-powered communication cabinets
Lithium-ion batteries deliver high energy density and long cycle life. These batteries require advanced battery management systems (BMS) to ensure safety and performance, especially in. Lithium-ion and lead-acid batteries each have benefits; selecting the best battery depends on site needs, budget, and maintenance capabilities. Integrating smart monitoring and advanced controllers helps detect issues early, supports predictive maintenance, and keeps systems running smoothly. A telecom battery backup system is a comprehensive portfolio of energy storage batteries used as backup power for base stations to ensure a reliable and Discover the importance of battery charging cabinets for safe lithium-ion battery storage. Learn about key features, benefits, and best practices. Somewhere in the background, likely baking in the sun or enduring a blizzard, is an outdoor photovoltaic energy cabinet and a telecom battery cabinet, quietly powering our digital existence non-stop. You might be a telecom infrastructure manager, a green energy consultant, or perhaps someone tired. Integrates solar input, battery storage, and AC output in a compact single cabinet.
[PDF Version]
-
CRRC makes energy storage lithium batteries
Our battery energy storage system (BESS) product portfolio spans the largest utility scale batteries down to commercial systems. CRRC has installed/signed 48+ GWh (Q2 2025) of grid connected BESS, with #1 ranking in China, #3 globally, Bloomberg Tier 1 and a growing. The world's largest rolling stock manufacturer says that its new container storage system uses LFP cells with a 3. The system also features a DC voltage range of 1,081. China-based rolling stock manufacturer CRRC has launched a 5 MWh battery storage system that. China-based rolling stock manufacturer CRRC has launched a 5 MWh battery storage system that uses liquid cooling for thermal management. Under the terms of the deal, HiTHIUM will supply no less than 120 GWh of energy storage products.
-
How much does a solar container lithium battery pack cost per kilowatt-hour
On average, it costs around $1,300 per kWh to install a battery before incentives. TL;DR: Wholesale lithium-ion pack prices averaged about $0. 115/Wh globally in 2024 (down ~20% YoY), but finished consumer systems (portable power stations) retail much higher due to inverters, BMS, certifications, and margins. Why trust EnergySage? How much do solar batteries cost? How much do solar batteries cost in your state? What impacts the cost of solar batteries? Picture this: The grid goes down during a summer storm. The lithium battery price in 2025 averages about $151 per kWh. Outdoor power tools and forklift lithium battery costs depend on amp hours, ranging from $110 for 2 Ah models to $335 for 12 Ah. Lithium-ion battery pack prices dropped 20% from 2023 to a record low of $115 per kilowatt-hour, according to analysis by research provider BloombergNEF (BNEF). Factors driving the decline include cell. The total cost of a solar battery system includes more than just the battery itself.
[PDF Version]
-
Lithium batteries are essentially energy
The lifespan of a lithium-ion battery is typically defined as the number of full charge-discharge cycles to reach a failure threshold in terms of capacity loss or impedance rise. Manufacturers' datasheet typically uses the word "cycle life" to specify lifespan in terms of the number of cycles to reach 80% of the rated battery capacity. Simply storing lithium-ion batteries in the charged state also.
FAQs about Lithium batteries are essentially energy
What is a lithium-ion battery?
The lithium-ion battery, which is used as a promising component of BESS that are intended to store and release energy, has a high energy density and a long energy cycle life .
What is a lithium ion battery used for?
More specifically, Li-ion batteries enabled portable consumer electronics, laptop computers, cellular phones, and electric cars. Li-ion batteries also see significant use for grid-scale energy storage as well as military and aerospace applications. Lithium-ion cells can be manufactured to optimize energy or power density.
How do lithium ion batteries work?
All lithium-ion batteries work in broadly the same way. When the battery is charging up, the lithium-cobalt oxide, positive electrode gives up some of its lithium ions, which move through the electrolyte to the negative, graphite electrode and remain there. The battery takes in and stores energy during this process.
What are the advantages and disadvantages of lithium ion batteries?
Compared to traditional nickel hydride or nickel-cadmium rechargeable battery technology, lithium-ion batteries have several advantages: primarily, they charge in less time and take longer to discharge, but they also have a higher energy density, have no memory effect and lose virtually no charge when not in use, etc.
How much energy does it take to make a lithium ion battery?
Manufacturing a kg of Li-ion battery takes about 67 megajoule (MJ) of energy. The global warming potential of lithium-ion batteries manufacturing strongly depends on the energy source used in mining and manufacturing operations, and is difficult to estimate, but one 2019 study estimated 73 kg CO2e/kWh.
Are lithium-ion batteries a good power storage technology?
Because of their elevated power compression, low self-discharge feature, practically zero-memory effect, great open-circuit voltage, and extended longevity, lithium-ion batteries (LIBs) have resumed to attract a lot of interest as a probable power storage technology.
-
How high temperature can lead-acid batteries withstand
For lead-acid batteries, including sealed, Gel, and AGM types, higher temperatures reduce lifespan. Specifically, for every 15 degrees Fahrenheit above 77°F, battery life decreases by half.
FAQs about How high temperature can lead-acid batteries withstand
What temperature should a lead acid battery be charged?
Here are the permissible temperature limits for charging commonly used lead acid batteries: – Flooded Lead Acid Batteries: – Charging Temperature Range: 0°C to 50°C (32°F to 122°F) – AGM (Absorbent Glass Mat) Batteries: – Charging Temperature Range: -20°C to 50°C (-4°F to 122°F) – Gel Batteries:
Can a lead acid battery be discharged in cold weather?
When it comes to discharging lead acid batteries, extreme temperatures can pose significant challenges and considerations. Whether it's low temperatures in the winter or high temperatures in hot climates, these conditions can have an impact on the performance and overall lifespan of your battery. Challenges of Discharging in Low Temperatures
How does heat affect a lead acid battery?
On the other end of the spectrum, high temperatures can also pose challenges for lead acid batteries. Excessive heat can accelerate battery degradation and increase the likelihood of electrolyte loss. To minimize these effects, it is important to avoid overcharging and excessive heat exposure.
How hot should a lead-acid battery be?
Only at very high ambient air humidity (above 70%), water from outside the battery can be absorbed by the hygroscopic sulfuric acid. In summary, the internal temperature of any lead-acid battery (flooded and AGM) should not exceed 60 °C for extended time periods frequently to limit vaporization. 2.1. External and internal heating of the battery
Why do lead acid batteries take so long to charge?
Here are some key points to keep in mind: 1. Reduced Charge Acceptance: At low temperatures, lead acid batteries experience a reduced charge acceptance rate. Their ability to absorb charge is compromised, resulting in longer charging times. 2. Voltage Dependent on Temperature: The cell voltages of lead acid batteries vary with temperature.
How does temperature affect lead-acid batteries?
Temperature plays a crucial role in the performance and longevity of lead-acid batteries, influencing key factors such as charging efficiency, discharge capacity, and overall reliability. Understanding how temperature affects lead-acid batteries is essential for optimizing their usage in various applications, from automotive to industrial settings.
-
How to connect the lithium battery module power supply
The simplest way to make your designs portable is to design them in a way that allows the user to quickly and easily change the battery when necessary. Then, the user could employ a regular external 18650 battery charger: External battery chargers can be a quick and easy solution as long as your project. Another easy-to-implement option is using an Arduino-compatible board that already comes fitted with an onboard Li-Ion and LiPo charging circuit. Regardless of their age, classic Arduino boards such as the UNO are still popular due to their low entry price, form-factor, and ease of use. These boards, however, don't support Lithium batteries right out of the box. Using a dedicated. As a last resort, you can also create a custom charger design using off-the-shelf components such as battery management PMICs. You'll need a good. By far, the most popular option for adding a Lithium battery in a DIY project is to utilize a simple charger breakout module. These often-tiny modules offer a fantastic mix between flexibility,.
[PDF Version]
FAQs about How to connect the lithium battery module power supply
How do I charge a lithium battery?
The lithium battery is connected to the BAT+ and BAT- pads on the right-hand side. If you are using the board with the protection circuit, you can connect the output to the OUT+ and OUT- pads. Connect the output wires to the BAT+ and BAT- if your board does not have a protection circuit. The charging current is set to 1 A.
How do I power a lithium ion board?
You have the option to power the board via a USB cable or by attaching an external power source to the IN+ and IN- pads on the left-hand side. The lithium battery is connected to the BAT+ and BAT- pads on the right-hand side. If you are using the board with the protection circuit, you can connect the output to the OUT+ and OUT- pads.
Can a lithium battery be used as a charge module?
All this means that you can employ unprotected Lithium cells such as standard 18650 batteries in combination with common charge modules. Off-the-shelf battery modules are a good way to secure a project that uses batteries against common faults that might occur while charging or discharging a Lithium battery.
How can NodeMCU be operated through a 3.7V lithium-ion battery?
We will also integrate a Battery Booster or Boost Converter Circuit so that NodeMCU can be operated through 3.7V Lithium-Ion Battery. The Battery can get discharged after using it for a long time, so we will also integrate a Battery Charger Circuit to the Board which has a feature of Battery Management System.
How to add a lithium battery in a DIY project?
By far, the most popular option for adding a Lithium battery in a DIY project is to utilize a simple charger breakout module. These often-tiny modules offer a fantastic mix between flexibility, safety, and cost-efficiency, and they are typically remarkably easy to use.
Can a lithium ion battery charge a NodeMCU board?
Most of the Lithium-Ion Batteries available in the market can only fully charge up to 4.2V which is not enough for NodeMCU Board. So we need to convert the voltage from Battery to 5V. That is the reason why we are using a small boost converter Module made using some inductors, IC & resistor.
-
How much does the China-Europe energy storage solar container lithium battery cost
The energy storage system is essentially a straightforward plug-and-play system which consists of a lithium LiFePO4 battery pack, a lithium solar charge controller, and an inverter for the voltage requested. Price for 1MWH Storage Bank is $774,800 each plus freight shipping from. in 40ft Containers. But this range hides much nuance—anything from battery chemistry to cooling systems to permits and integration. Let's deconstruct the cost drivers. Let's cut to the chase: whether you're a German homeowner with solar panels or a Chinese manufacturer eyeing European markets, solar energy storage battery prices directly impact your wallet. The consultancy's ESS Pricing Forecast Report for Q2 2024 said that BESS suppliers are moving to +300Ah cells quicker than. A new analysis from energy think tank Ember shows that utility-scale battery storage costs have fallen to $65 per megawatt-hour (MWh) as of October 2025 in markets outside China and the US.
[PDF Version]
-
Lithium batteries for energy storage are replaced by sodium
Sodium-ion batteries (SIBs) offer a compelling alternative to lithium-based cells. They use the same basic rechargeable architecture, but swap lithium for abundant, lower-cost sodium - which means rethinking electrode materials and electrolytes to make the chemistry work. As global demand for clean energy and sustainable battery solutions skyrockets, one big question looms over the energy industry: Can sodium batteries replace lithium batteries? While lithium-ion batteries continue to dominate the energy storage and EV markets, sodium-ion technology is emerging as a. Sodium-ion batteries show promise as a cheaper, more sustainable alternative to lithium-ion but need major advancements to become competitive. A challenge for sodium-based. A surprising breakthrough could help sodium-ion batteries rival lithium—and even turn seawater into drinking water. Scientists discovered that keeping water inside a key battery material, instead of removing it as traditionally done, dramatically boosts performance. While lithium-ion technology dominates electric vehicles (EVs) and consumer electronics.
[PDF Version]
-
How to melt the lead in lead-acid batteries
Lead From Lead Acid BatteriesStep 1: Gather Your Materials Materials in no particular order: 1. Step 2: Dump the Acid Out Now would be a good time to put on the safety glasses and gloves.
FAQs about How to melt the lead in lead-acid batteries
How does a lead-acid battery function?
A lead-acid battery, commonly used as a car ignition battery, functions with a lead plate and a lead dioxide plate, with a sulfuric acid electrolyte in between. As energy is discharged from the battery, the lead plate reacts with sulfuric acid to form lead sulfate and electrons.
Can I reuse a lead acid battery?
Your old lead acid battery will be recycled by Yuasa Batteries free of charge. No, automotive batteries contain lead, acid, and lead compounds, all of which are considered harmful to humans.
What happens if lead acid battery plate active materials are dissolved?
If Lead Acid battery plate active materials are dissolved then battery will no longer sustain recharge cycle that means battery dies. Maintaining Lead Acid battery with proper Recharge circuit can extend the lifespan. This circuit is designed to charge 6V and 12V battery and Switch S1 decides the output voltage.
What is the composition and plate-making process for a lead acid battery?
The negative plates in a lead acid battery are made using a composition that includes a polymer mixed with lead oxide, water, an expander, and sulfuric acid. This forms a negative paste composition with the expander and basic lead sulfate crystals having the polymer absorbed on their surfaces. The passage describes a process for reducing active material shrinkage in these batteries.
Can lead acid batteries be recycled?
Lead acid batteries should not be placed in home recycling or waste bins as the lead and acid may contaminate other recycled materials and render them un-usable. Nothing is charged for recycling lead acid batteries at Yuasa Batteries.
What is a lead battery recycling plant?
In a lead battery recycling plant, the lead-acid batteries are first broken down into their component parts, which typically includes the lead plates, lead oxide paste, and plastic components. The lead plates and lead oxide paste are then smelted in a furnace to extract the lead.