Browse technical resources about solar mounting systems, tracker technology, structural design, and installation best practices.
HOME / Milk Frother, Battery Powered Milk Frother Electric - BeTheFuture Solar Foundation & Infrastructure
The DELTA 2 Portable Power Station is a medium-capacity plug-and-play power station suitable for extended power outages. Depending on your needs, you can expand the power output and storage capacity from its initial 1 kWh rating to 2 kWh or 3 kWh. The higher capacity ratings allow you to power most. The EcoFlow Delta Pro Portable Power Station is a higher capacity option than the DELTA 2, starting at 3.6 kWh and expandable to 25 kWh. The DELTA Pro can run multiple high-wattage appliances and expand to a whole. The DELTA Pro can provide enough power for the average home to run essential appliances during a one-day blackout. For more extended power outages (and greater energy security), the advanced EcoFlow Whole. The EcoFlow Smart Home Ecosystemalso uses DELTA Pro portable power stations and a Smart Home Panel that integrates directly with your home. All things being equal, more power is better during a blackout. Except for the DELTA 2, all the options above begin with DELTA Pro portable power stations. It's no wonder: these high-capacity units deliver and store enough power.
[PDF Version]
Battery storage, or battery energy storage systems (BESS), are devices that enable energy from renewables, like solar and wind, to be stored and then released when the power is needed most.
A Battery Energy Storage System (BESS) is a system that uses batteries to store electrical energy. They can fulfill a whole range of functions in the electricity grid or the integration of renewable energies. We explain the components of a BESS, what battery technologies are available, and how they can be used.
The battery system is connected to the inverters, in order to convert the power in AC. In each BESS there is a specific power electronic level, called PCS (power conversion system) usually grouped in a conversion unit, including all the auxiliary services needed for the proper monitoring.
This is known as electrochemistry and the system that underpins a battery is called an electrochemical cell. A battery can be made up of one or several (like in Volta's original pile) electrochemical cells. Each electrochemical cell consists of two electrodes separated by an electrolyte.
Power It is the name of the voltage times current of the battery. More power means a battery can do work quickly. The power of a battery depends on both current and voltage, which shows the importance of both terminologies in helping the battery perform its functions seamlessly.
There are various types of batteries. Based on charging capacity we can divide them in two types: 1. Primary Cell Battery Primary cell batteries are designed to be used for once, and discharged. We cannot recharge this type of batteries. Some example of primary cell batteries are.
Primary batteries readily available to consumers range from tiny button cells used for electric watches, to the No. 6 cell used for signal circuits or other long duration applications. Secondary cells are made in very large sizes; very large batteries can power a submarine or stabilize an electrical grid and help level out peak loads.
The systems we sell and market are guaranteed to provide full power for 10 years. After that, the amount of energy the system can carry will gradually drop down to about 80%.
By definition, a Battery Energy Storage Systems (BESS) is a type of energy storage solution, a collection of large batteries within a container, that can store and discharge electrical energy upon request.
The amount of time storage can discharge at its power capacity before exhausting its battery energy storage capacity. For example, a battery with 1MW of power capacity and 6MWh of usable energy capacity will have a storage duration of six hours. Depth of Discharge (DoD) expresses the total amount of capacity that has been used.
Environmental Impact: As BESS systems reduce the need for fossil-fuel power, they play an essential role in lowering greenhouse gas emissions and helping countries achieve their climate goals. Despite its many benefits, Battery Energy Storage Systems come with their own set of challenges:
Industrial and Commercial Applications: Factories, warehouses, and large facilities use BESS to manage their power loads efficiently, reducing energy costs and promoting sustainable operations. Battery Energy Storage Systems offer a wide array of benefits, making them a powerful tool for both personal and large-scale use:
Battery lifespans vary, with lithium-ion batteries lasting 10-15 years on average, depending on use. How much does it cost to install a BESS? Costs vary widely; residential systems can start around $5,000, while commercial setups may run into the millions.
A full battery energy storage system can provide backup power in the event of an outage, guaranteeing business continuity. Battery systems can co-locate solar photovoltaic, wind turbines, and gas generation technologies.
Battery energy storage systems can enable EV fast charging build-out in areas with limited power grid capacity, reduce charging and utility costs through peak shaving, and boost energy storage capacity to allow for EV charging in the event of a power grid disruption or outage.
One of the most effective ways to achieve this is by integrating Battery Energy Storage Systems (BESS) with EV charging stations. This innovative approach enhances grid stability, optimizes energy costs, and supports the transition to a more sustainable transportation ecosystem. Power Boost and Load Balancing
Battery energy storage systems can help reduce demand charges through peak shaving by storing electricity during low demand and releasing it when EV charging stations are in use. This can dramatically reduce the overall cost of charging EVs, especially when using DC fast charging stations.
Incorporating energy storage into EV charging infrastructure ensures a resilient power supply, even during grid fluctuations or outages. This reliability is crucial for businesses that rely on EV fleets for daily operations, as well as municipalities working toward sustainable public transportation solutions.
Fortunately, there is a solution, and that solution is battery energy storage. The battery energy storage system can support the electrical grid by discharging from the battery when the demand for EV charging exceeds the capacity of the electricity network. It can then recharge during periods of low demand.
Battery energy storage can store excess renewable energy generated by solar or wind and release it when needed to power EV charging stations. This can help increase renewable energy use and reduce reliance on fossil fuels.
The integration of EV charging infrastructure with Battery Energy Storage Systems is more than just a technological advancement; it's a shift in how we view and manage energy. This integration promises a future where energy is not only consumed more efficiently but also generated and stored sustainably.
Charging lithium batteries effectively requires essential components like solar panels, charge controllers, batteries, and inverters. When it comes to solar power, the efficiency of the charging process hinges on the quality of these components. Lithium batteries, being sensitive to voltage fluctuations, necessitate the use of. When picking solar panels for charging lithium batteries, it's essential to take into account panel efficiency factors, size, and wattage. These elements play a significant role in determining how effectively your batteries will charge. Ensuring the safe and efficient charging of lithium batteries with solar power requires the use of charge controllers. These devices play a vital role in. Discussing the efficient methods for charging lithium batteries is essential for maximizing their performance and longevity when using solar power. To guarantee ideal charging, several key factors must be.
[PDF Version]To charge lithium batteries with solar panels, you'll need specific equipment: Solar Panels: Choose from options such as monocrystalline, polycrystalline, or thin-film based on your energy needs and budget. Charge Controller: This device regulates the voltage and current coming from the solar panels to the battery, preventing overcharging.
To set up a solar charging system for lithium batteries, gather the following equipment: Solar Panels: Choose panels that produce sufficient wattage to match your energy needs. Options typically range from 100 to 400 watts. Charge Controller: Utilize a solar charge controller to regulate voltage and current flowing into the battery.
Utilize advanced technology and efficient charging methods for battery longevity. Charging lithium batteries effectively requires essential components like solar panels, charge controllers, batteries, and inverters. When it comes to solar power, the efficiency of the charging process hinges on the quality of these components.
Monocrystalline Panels: Known for their higher efficiency and space-saving design, they are ideal for charging lithium batteries efficiently. Properly matching the size and wattage of the solar panel to the battery capacity is essential for efficiently charging lithium batteries with solar power.
You need a solar charge controller to charge any 12V battery with a solar panel. You also need to take into account the correct size cable for the 12v solar panel. A portable generator may be an exception because it should have one built-in and an inverter. You may not know how to set up solar panels off the grid.
Lithium-ion batteries have a battery management system (BMS) to prevent overcharging. You should, however, always have a solar charge controller in your solar setup kit. Your lithium-ion battery will be kept safe if you invest in a good quality solar controller. This will make the charging process more efficient.
Lead acid and lithium-ion batteries dominate the market. This article offers a detailed comparison, covering chemistry, construction, pros, cons, applications, and operation.
Lead-acid batteries are the oldest technology and have the shortest lifespan, making them less popular for electric cars. Ultimately, each type of battery has its own pros and cons, and it's important to consider factors like cost, lifespan, and energy efficiency when comparing electric car batteries.
Lithium-ion batteries are lighter and more compact than lead-acid batteries for the same energy storage capacity. For example, a lead-acid battery might weigh 20-30 kilograms (kg) per kWh, while a lithium-ion battery could weigh only 5-10 kg per kWh.
The primary difference lies in their chemistry and energy density. Lithium-ion batteries are more efficient, lightweight, and have a longer lifespan than lead acid batteries. Why are lithium-ion batteries better for electric vehicles?
On contrary, lead is a carcinogenic material that is harmful to the environment. Even lead-acid batteries contain other chemicals such as sulphuric acid that are poisonous. But the recycling rate for lead-acid batteries is higher than Li batteries. Also, lead-acid batteries are cheaper because of their wide availability.
Lead-acid batteries remain an essential component in the battery industry. Despite not matching the energy capacity of newer batteries, their reliability, low cost, and high current delivery make Lead-acid batteries invaluable for certain uses.
2. Lead-Acid Batteries: Working: Lead-acid batteries utilize lead dioxide as the cathode and sponge lead as the anode immersed in a sulfuric acid electrolyte. During discharge, lead and lead dioxide react with sulfuric acid to produce electricity.
The characteristics that define an EV battery performance are listed below: 1. Battery Capacity 2. C-Rate 3. Weight 4. Size 5. Power In order to understand them in detail, keep on reading the article. Battery capacity or Energy capacity is the ability of a battery to deliver a certain amount of power over a while. It is measured in kilowatt-hours (product of voltage and ampere-hours). It determines the energy available to the. A C-rating is used to define the rate at which a battery is fully charged or discharged. For instance, when the vehicle with an 85kWh battery is. The size of the battery of an electric vehicle has its own significance. Energy per volume is important to building a compact EV. Volumetric energy density means an amount of energy contained within a certain volume.It. The major part of an EV's weight comes from its battery. In general gross weight of a passenger EV, varies from 600kg to 2600kg with the battery weight varying from 100kg to 550kg.
[PDF Version]There are four main types of batteries that are used in electric vehicles, namely ultracapacitors / supercapacitors, lead-acid batteries, nickel-metal hydride batteries and lithium-ion batteries. In the ultracapacitor polarized liquid is stored between an electrode and an electrocyte.
Li-ion batteries are the preferred choice for modern electric cars due to their advanced rechargeable battery technology. However, they are relatively expensive to produce compared to other battery types. Nickel-Metal Hydride (NiMH) batteries gained commercial use in the late 1980s.
Beyond their 1500 charges and useful lifespan in a vehicle, electric vehicle batteries can be used for energy storage where performance isn't so important. For example, they can be used in motorhomes to store solar power, or as a backup for a power cut in our homes. Why are electric car batteries so expensive?
An electric vehicle battery is a rechargeable battery used to power the electric motors of a battery electric vehicle (BEV) or hybrid electric vehicle (HEV). They are typically lithium-ion batteries that are designed for high power-to-weight ratio and energy density.
NiMH batteries are known for their recyclability and are proven to be a suitable option for EVs, with an average battery life of 5-7 years. Lead-Acid batteries, formulated in 1859, are the oldest type of battery still in use. They are known for their low cost but have a shorter lifespan of around 3 years.
Nowadays, Lithium-ion batteries are by far the most widely used, this is due to them recharging quickly, being robust against temperature changes, and being able to maintain power for long durations, with bursts of very high power.
The short answer is that you can charge a 6-volt battery with a 12-volt charger. So, what's the catch? The catch is that it can be dangerous to do so. On the other hand, you cannot charge a 12-volt battery with a 6-volt charger. There is no danger in trying to charge a 12v battery with a 6v charger. There is not enough. Ideally, the best solar panel to use to charge a six-volt battery is a six-volt solar panel. Because solar energy ebbs and flows throughout the day, the panel will deliver less than six volts of current at its weakest power. In short, a solar charge controller or a solar regulator limits the amount of energy from an array to its components, especially for Solar. There are different types of solar regulators. They are PWM — Pulse With Modulation and MPPT or Maxim PowerPoint Tracking regulators, and they work differently. PWM Regulators— The keyword here is PULSE. You can charge a six-volt battery directly without a solar regulator, but you do so at significant risk. A solar regulator on the cheaper end is around $50. However, the regulator's cost is minimal.
[PDF Version]This guide will help you to charge your 6V battery with a right solar panel that can meet your needs. = Battery Voltage * 1.5 times =6V * 1.5 ~9.6V Hence, After multiplying the battery voltage by 1.5 times, we get the Solar Panel's IMP required to charge a 6V Battery with a solar panel Maximum Power Voltage (Vmp) = 9V = 0.52 *12
The solar panel will provide a little over 9 volts at its peak. Given that a six-volt battery is 100 percent charged at around seven volts, the pairing of the panel to a battery works when both are six volts. While that sounds good news, it is not always a good fit. Are we talking in circles? Nope, and here's why.
A 6 volt solar battery, also known as a SLA AGM battery, is used to store solar energy from offgrid systems using photovoltaic technology. 2. How do you charge this type of battery?
It is important to charge the batteries only with a required and sufficient voltage panels, If the solar panels have much higher voltage and more power output, Then the batteries without an external overcharging circuit risk overcharging battery damages or battery degradation in the long run.
For example, let's say your estimated charge time is 8 peak sun hours and your location gets on average 4 peak sun hours per day. In that case, you know it'll take about 2 days for your solar panel (s) to charge your battery. Besides using our calculator, here are 3 ways to estimate how long it'll take to charge a battery with solar panels.
You can charge a six-volt battery directly without a solar regulator, but you do so at significant risk. A solar regulator on the cheaper end is around $50. However, the regulator's cost is minimal if you use the solar panel to charge the battery over many years.
The steel material for this battery is physically stable with its stress resistance higher than aluminum shell material. It is mostly used as the shell material of cylindrical lithium batteries. Structure of Steel Sheel Battery In. The aluminum shell is a battery shell made of aluminum alloy material. It is mainly used in square lithium batteries. They are environmentally friendly and lighter than steel shell batteries while having strong plasticity and stable. The pouch-cell battery (soft pack battery) is a liquid lithium-ion battery covered with a polymer shell. The biggest difference from other batteries is its.
The shell materials used in lithium batteries on the market can be roughly divided into three types: steel shell, aluminum shell and pouch cell (i.e. aluminum plastic film, soft pack). We will explore the characteristics, applications and differences between them in this article.
Aluminum shell batteries are the main shell material of liquid lithium batteries, which is used in almost all areas involved. The pouch-cell battery (soft pack battery) is a liquid lithium-ion battery covered with a polymer shell.
The following companies are recognized as leading players in the lithium battery industry: CATL, BYD, EVE, Guoxuan Hi-Tech, Penghui Energy, Chuaneng Power, Sunwoda, and AVIC Lithium Battery. For more information, you can also refer to other related best lists about lithium batteries.
It is mainly used in square lithium batteries. They are environmentally friendly and lighter than steel shell batteries while having strong plasticity and stable chemical properties. Generally, the material of the aluminum shell is aluminum-manganese alloy, and its main alloy components are Mn, Cu, Mg, Si, and Fe.
The steel material for this battery is physically stable with its stress resistance higher than aluminum shell material. It is mostly used as the shell material of cylindrical lithium batteries. Structure of Steel Sheel Battery
At present, most laptops use steel-shell batteries, but it is also used in toy models and power tools. The aluminum shell is a battery shell made of aluminum alloy material. It is mainly used in square lithium batteries.
To troubleshoot and diagnose the battery not charging problem on your laptop follow the below steps in order:Check Power Supply connections & Battery. Run Windows Battery Troubleshooter.
If your battery isn't fully charging, the first thing you can try is the Battery troubleshooter in Windows 10. Complete the wizard then restart your device to see if the problem is resolved. Most laptop computers include their own factory diagnostics utilities, too. It is recommended you also use those to test your battery.
To see if Windows can fix the battery not charging problem, you can run the power troubleshooter. 1. In the search type "troubleshoot settings " and then click to open them from the search results. 2. In the 'Troubleshoot' window, select Additional troubleshooters. 3. Scroll down and click on Power.
Battery not charging to full If you experience the problem which is The battery doesn't be charged when power level is above 95% with AC adapter connected. This is a normal condition for battery protection, not a problem for either the battery itself or the charging function. When the battery is charged to 100%, it will stop being charged.
To troubleshoot and diagnose the battery not charging problem on your laptop follow the below steps in order: Check Power Supply connections & Battery. Check Power Cable & Battery Connection. Disconnect External Devices. Diagnose Battery Health. Run Windows Battery Troubleshooter. Uninstall & Reinstall Battery Device Driver. Update Chipset Drivers.
Because one cannot run on battery power alone. It's a good idea to keep up with Windows updates so your system can continue to run smoothly and your data stays secure. On occasion, however, an update can cause a conflict that breaks something. After installing a previous Windows update, for example, my laptop's battery stopped charging.
Plug in your laptop. Power on your laptop. Click the battery icon in the system tray and you should see that your laptop is plugged in and charging. By reinstalling my Lenovo laptop's battery drivers and disconnecting its battery and then reconnecting it, I got my laptop's battery back to charging when it's plugged in.
An automotive battery is a battery of any size or weight used for one or more of the following purposes: 1. starter or ignition power in a road vehicle engine 2. lighting power in a road vehicle An industrial battery or battery pack is of any size or weight, with one or more of the following characteristics: 1. designed exclusively for industrial or professional uses 2. used as a source. A battery pack is a set of batteries connected or encapsulated within an outer casing which is: 1. formed and intended for use as a single, complete unit 2. not intended to be split up or opened A portable battery or battery pack is a battery which meets all the following criteria: 1. sealed 2. weighs 4kg or below 3. not an automotive or industrial battery 4. not designed exclusively. The 2008 and the 2009 regulations do not define a sealed battery. Defra and the regulators have adopted the International Electrotechnical Commission's (IEC) definition of a 'sealed cell'.
[PDF Version]This Classification Note provides requirements for approval of Lithium-ion battery systems to be used in battery powered vessels or hybrid vessels classed or intended to be classed with IRS.
Sealed batteries weighing 4kg or below may still be classed as industrial if they are designed exclusively for professional or industrial use. If a battery producer wants to classify a battery as designed exclusively for professional or industrial use, weighing 4kg or below, they must provide evidence for that classification.
Battery system is an “Energy storage device that includes cells or cell assemblies or battery pack (s) as well as electrical circuits and electronics (e.g., BCU, contactors)” [ 20 ]. Chassis/body in white (BiW) is the outer shell of the battery electric vehicle (BEV) [ 21] (p. 3).
Type approval would be required for each type of Li-ion battery (i.e. for each battery chemistry). The type approval process consists of the following: type testing & functional testing, (review type test records if the tests are carried out in Govt. lab or were witnessed by any other IACS society.
Primary batteries are non-rechargeable. The secondary batteries i.e. batteries which can be recharged have further variants based on the battery chemistry. The type of electrolyte used, aqueous (acid, alkaline) or non aqueous play a major role in battery energy density and safety. The primary focus of the survey procedure is on secondary batteries.
The battery system manufacturer is to prepare and implement a quality plan that defines procedures for the inspection of materials, components, cells, modules, battery packs, and battery systems and which covers the whole process of producing each type of cell, module, battery pack, and battery system.
This article summarizes top 10 manufacturers of global energy storage batteries. They are CATL, BYD, EVE, REPT,HTHIUM, Great Power, Envision Energy, CALB, GOTION HIGH-TECH, Ganfeng Lithium.
This article will mainly explore the top 10 energy storage manufacturers in the world including BYD, Tesla, Fluence, LG energy solution, CATL, SAFT, Invinity Energy Systems, Wartsila, NHOA energy, CSIQ. In recent years, the global energy storage market has shown rapid growth.
As the top battery energy storage system manufacturer, The company is renowned for its comprehensive energy solutions, supported by advanced industrial facilities in Shenzhen, Heyuan, and Hefei. Grevault, a subsidiary of Huntkey, is a leader in the battery energy storage sector.
First, we'll take a look at the top 10 quoted batteries on the EnergySage Marketplace: Enphase takes the top place with its IQ 10 Battery, which includes 10.08 kilowatt-hours (kWh) of usable capacity.
On the EnergySage Marketplace, the most popular battery brands include Enphase and Tesla. In the first quarter of 2022, the most commonly quoted and selected battery on the Marketplace nationwide was the Enphase IQ 10 Battery.
LG Chem, a branch of the LG conglomerate, boasts a rich lineup of lithium-ion batteries. Their RESU series, known for its compactness and efficiency, is popular among homeowners seeking solar energy storage solutions. 4.3. Panasonic Once Tesla's primary battery cell provider, Panasonic is an industry veteran with over a century of experience.
LG Energy Solution, coming in at third, has the most battery models in the top 10 spots: the RESU 10H, RESU Prime 16H, and RESU Prime 10H are among the most quoted batteries on the EnergySage Marketplace.
Specific Steps for Regular MaintenanceRegular Monitoring of Battery Status: Use specialized equipment to measure the battery's voltage, internal resistance, capacity, and temperature. Inspect Cables and Connectors:. Maintain the Thermal Management System:.
Establishing an adequate battery maintenance procedure is essential for ensuring a productive & safe work environment. Charts and maintenance plans are a fantastic approach to ensuring that batteries are properly maintained. Battery maintenance is essential for ensuring their best performance and longevity.
Different types of batteries, such as lead-acid and lithium-ion, require specific maintenance techniques to ensure their longevity and performance. Knowing the type of battery you are working with is essential to guarantee the correct charging and maintenance techniques are employed.
Specific maintenance requirements will vary depending on the type of battery; however, the following are general step-by-step procedure that apply to many different types of batteries, including lead-acid batteries typically used in cars and uninterruptible power supply (UPS) systems. Step-2: Do Not Top Off Before Charging
From visual inspections & cleanliness to evaluating electrolyte levels (if appropriate), charging system tests, and load testing, this complete approach covers essential procedures for maintaining several battery types, including lead-acid & lithium-ion.
It is still important to check their state of charge regularly using a monitoring tool that interacts with the integrated battery management system. Proper charging practices, such as quick charging of the battery after each period of use, will also help maintain their performance.
Construction equipment batteries, including deep cycle batteries, may require additional maintenance due to harsh operating conditions. Ensuring proper maintenance for all batteries used for construction equipment can help prevent costly downtime and keep your equipment running smoothly.
The CEIV Li-batt certification assesses your organization based on the guidelines for the Dangerous Goods Regulations (DGR) andLithium Battery Shipping Regulations (LBSR), and covers the following critical areas of lithium battery handling and carriage operations: 1. Quality and safety management - Including organization. The IATA Certification process is designed to guide and support you to success. We give you the understanding, tools and expert advice you need to achieve your organization's certification. The process is as follows: 1. Training - At.
Transport Document: For lithium battery shipments, this specifies the UN number, shipping name, hazard class, packing group, and total quantity. Pilot Notification: For shipping lithium batteries by air, pilots must receive written information on the presence and location of lithium batteries.
In addition, lithium-ion cells and batteries shipped by themselves must be shipped at a state of charge not exceeding 30% of their rated capacity. Lithium batteries are dangerous goods, and all of the regulatory requirements must be complied with, as set out in the Lithium Battery Shipping Regulations.
That's why the International Air Transport Association (IATA) is promoting the increased viability of air transport for lithium-ion batteries through a four-part approach: Promote the development of outcome-based, harmonized safety-related screening standards and processes for lithium batteries.
As far as transport is concerned, lithium batteries, if properly certified and specially packaged, can be shipped by road, sea, rail or air. However, medium and large batteries are among the goods not accepted by airlines, which disallow their transportation on cargo flights.
A table in the Lithium Battery Shipping Regulations manual gives the precise weight of batteries per package on both cargo and passenger aircraft. All marks and labels must be clearly visible on the exterior of all packages and overpacks. Proper marking and labeling is required when shipping lithium batteries by air.
NOTE: “Section II” Lithium Battery shipments that are compliant for Air transport (i.e. as per section II of the relevant Packing Instructions from the IATA DGR) also comply with all requirements of ADR/IMDG Special Provision 188 and can therefore be transported by Road in ADR affiliated countries and globally by Sea. 4.
In this article, we will examine a circuit that allows charging Li-ion cells connected in series while also balancing them during the charging process.
The following graph suggests the ideal charging procedure of a standard 3.7 V Li-Ion Cell, rated with 4.2 V as the full charge level. Stage#1: At the initial stage#1 we see that the battery voltage rises from 0.25 V to 4.0 V level in around one hour at 1 amp constant current charging rate. This is indicated by the BLUE line.
If the cells are protected and one cell charges faster than the other it's protection will cut it off and current will not flow the other battery in series. That is the function of battery management circuits. Lithium ion batteries are fully charged at 4.2V, and discharged at about 3 V.
Although Li-Ion batteries are vulnerable devices, these can be charged through simpler circuits if the charging rate does not cause significant warming of the battery., and if the user does not mind a slight delay in the charging period of the cell.
It is possible to charge the cells individually, but limit the current and don't exceed 4.2V, and monitor the battery temperature. Many lithium batteries have built in protection for overdischarge.
The charging also different than the lead-acid batteries. The 3.9v Lithium-ion batteries need 4.2 v of charging voltage and 1A charging current. The charging time is about 2-3 hours. if the optimized charging is not done, the battery will be damaged or reduces the battery capacity.
You can also view the Lithium battery Charger PCB, how it will look after fabrication using the Photo View button in EasyEDA: After completing the design of this Lithium battery Charger PCB, you can order the PCB through JLCPCB.com. To order the PCB from JLCPCB, you need Gerber File.