This article will tell you some relevant knowledge about low-temperature li ion customized battery packs.
In our daily life, the most battery we use are the common battery. But in some special field, the low-temperature custom lithium battery pack is also used.
Special low-temperature li ion customized battery packs are rechargeable battery suitable for low-temperature environments of-40°C. The battery is required to reach more than 80% of the rated capacity when discharged at 0.2C. The main feature is that it has sufficient capacity at low temperature and can work normally.
Generally, lithium-ion battery cannot be used normally when the ambient temperature is -20°C, while low-temperature lithium-ion battery can still be used normally at -50°C.
In addition to communication power supplies, mobile power supplies, signal power supplies, and small EV power supplies also require low-temperature battery when working in the field.
Low-temperature li ion customized battery packs have the advantages of light weight, high density and long life, and are widely used in various electronic devices. Among them, low-temperature polymer lithium-ion battery also have the advantages of simple packaging, easy to change the geometric shape, ultra-light and ultra-thin, and high safety, becoming the power source of many mobile electronic products.
Currently, the low-temperature lithium-ion battery with better performance on the market is lithium cobalt oxide lithium-ion battery. Low-temperature li ion customized battery packs have the following advantages:
(1) High discharge performance, with a minimum discharge rate of 0.2C at -50°C and an efficiency of over 60%; and a discharge capacity of 80% at a discharge rate of 0.2C at -40°C;
(2) Wide operating temperature range, -50°C to 50°C;
(3) Excellent low-temperature cycle performance, charge and discharge at -30°C at 0.5C, and the capacity remains above 85% after 300 cycles;
(4) The size is flexible and can be customized in size and shape according to customer needs.
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Graphite negative electrode: artificial graphite AGP, artificial graphite S360, artificial graphite FSN-1, natural graphite 918-II, power type artificial graphite QE-1, power type artificial graphite QCG-X9, energy fast charging type artificial graphite QC8, low expansion rate Artificial graphite G49, etc.
Hard carbon anode: hard carbon for custom lithium battery pack, Kureray chemical hard carbon, Kuraray 509-5 (D50=5um), Kuraray 510-5 (D50=5um), spherical hard carbon, Kuraray type1, Kuraray type2
Lithium titanate, soft carbon, nano silicon 50nm, zinc foil and other materials
Electrolyte
Various electrolytes such as ternary material electrolyte, lithium-rich manganese-based electrolyte, lithium iron phosphate electrolyte, lithium cobalt oxide electrolyte, high voltage electrolyte, etc. can be prepared according to the specified formula or battery system.
Separator
Temini Super P Li, Japan Lion Ketjen Black ECP-600JD, Japan Lion Ketjen Black EC-300J, Temini KS-6, Temini SFG-6, acetylene black, single wall carbon nanotube slurry materials (water system/oil system), multi-walled carbon nanotube slurry, multi-walled carbon nanotube powder and other materials
Adhesive
American Solvay PVDF 5130, French Arkema PVDF HSV900, Japanese Daicel CMC 2200, Nippon Paper CMC MAC500LC, Japanese Zeon SBR BM-451b, JSR TRD104A, LA132, LA133, LA136D, LA136DL (lithiated polyacrylic acid bonded Agent PAA Li), PVP K30, PTFE and other materials
Kuraray Type2 hard carbon, Kuraray Type1 hard carbon, Kureha Chemical hard carbon, spherical hard carbon, NHC-B1, BSHC-300 and other materials
Electrolyte
Sodium vanadium phosphate electrolyte, sodium nickel ferromanganate semi-electrolyte, sodium nickel ferromanganate-hard carbon full electrolyte, sodium electrohard carbon electrolyte and other electrolytes can be prepared according to the specified formula or battery system
Separators
Whatman fiberglass separators (various specifications), special separators for sodium-ion batteries, etc.
Conductive agent
Temini Super P Li, Japan Lion Ketjen Black ECP-600JD, Japan Lion Ketjen Black EC-300J, Temini KS-6, Temini SFG-6, acetylene black, single wall carbon nanotube slurry materials (water system/oil system), multi-walled carbon nanotube slurry, multi-walled carbon nanotube powder and other materials
Adhesive
American Solvay PVDF 5130, French Arkema PVDF HSV900, Japanese Daicel CMC2200, Nippon Paper CMC MAC500LC, Japanese Zeon SBR BM-451b, JSR TRD104A, LA132, LA133, LA136D, LA136DL (lithiated polyacrylic acid binder PAA Li), PVP K30, PTFE and other materials
Current collector
Aluminum foil (single light/double light), carbon-coated aluminum foil (single-sided coating/double-sided coating) and other materials
Shells and other materials and tools
Button battery case, aluminum plastic film, tabs, N-methylpyrrolidone (battery grade), high temperature tape, cutting tools, soft pack battery test fixture, etc.
Nano-iron trioxide for batteries, nano-silica for batteries, nano-zinc oxide for custom lithium battery pack, nano-titanium dioxide for custom lithium battery pack, high-purity ultra-fine alumina for custom lithium battery pack, nano-aluminum hydroxide for lithium batteries, nano-alumina for lithium batteries, Nano-magnesium oxide for lithium batteries, nano-zirconia for lithium batteries.
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Custom lithium battery pack is becoming increasingly popular in today’s technology-driven world. The Custom Lithium Battery Pack ese packs are designed and built to meet the specific needs of individual customers, providing them with a custom-made solution for their specific application. Custom lithium battery packs offer a number of advantages over traditional battery packs, Custom Lithium Battery Pack including higher energy density, longer lifespan, and better safety performance. In this article, we will explore the benefits of custom lithium battery packs and how they can be used to meet the unique needs of individual customers.
One of the primary benefits of custom lithium battery packs is their high energy density. These packs typically provide Custom Lithium Battery Pack higher energy output than traditional battery packs, making them well-suited for applications that require a large amount of power, such as electric vehicles and power tools. Additionally, custom lithium battery packs also provide excellent performance in terms of power output and rechargeability, making them a cost-effective solution for meeting the power needs of various applications.
Another advantage of custom lithium battery packs is their long lifespan. These packs typically offer a longer lifespan than traditional battery packs, providing users with a long-term solution for their application. Additionally, custom lithium battery packs also provide excellent safety performance, making them a safer option for use in various applications.
Custom lithium battery packs are also designed to meet the specific needs of individual customers. These packs can be custom-built to meet the power requirements of various applications, including electric vehicles, power tools, and other consumer electronics. Additionally, custom lithium battery packs can also be designed to meet the specific needs of industrial applications, such as wind turbines and other large-scale energy systems.
In conclusion, custom lithium battery packs provide a number of advantages over traditional battery packs, including higher energy density, longer lifespan, and better safety performance. These packs are designed to meet the specific needs of individual customers, making them a cost-effective and safer option for meeting the power needs of various applications. As technology continues to advance and demand for energy-efficient solutions increases, custom lithium battery packs are expected to become even more popular in the future.
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Lithium (Li), as the charge carrier in traditional li ion customized battery packs and emerging lithium metal batteries, has always been an indispensable medium to ensure battery operation. However, battery energy, longevity, and safety improvements are urgently needed in various applications, including electric vehicles and grid energy storage. Currently, inactive lithium (dead lithium) in the form of a solid electrolyte interface phase (SEI) and metallic lithium that loses contact with the electrode and loses the conductive path are considered to be the main reasons for capacity fading and insufficient life. It depends largely on the nature of SEI on the negative electrode surface for these unfavorable factors.he volume change of lithium during cycling causes the SEI to rupture, fresh lithium is exposed to the electrolyte again to form a new SEI. Such repeated damage/repair of the SEI makes the previously used strategies to improve SEI stability unavailable. In addition, the potential relationship between SEI film fragments (dead SEI) and metallic lithium due to electrode disengagement and loss of conductive pathways is unclear, making clarifying strategies to suppress dead lithium to prevent battery failure more challenging.
In view of this, the team of Professor Tao Xinyong of Zhejiang University of Technology and Professor Lu Jun of Argonne National Laboratory (co-corresponding author) quantified the Li2O content in the SEI layer based on the recent understanding that Li2O dominates SEI on lithium metal anodes. More importantly, the team revealed the correlation between SEI film fragmentation and dead lithium and showed that lithium loss in the SEI and dead lithium fragmentation are major causes of expected performance degradation in lithium metal batteries.
Based on such findings, the team proposed a method to reduce SEI fragment content through the redox reaction of iodine mediator (I3-/I-), which can effectively activate electrochemistry in dead SEI and Inactive lithium. The proposed Li2O transfer from the dead SEI to the newly exposed lithium surface not only effectively eliminates the accumulation of dead SEI and lithium metal fragments during lithium deposition/stripping cycles but also significantly suppresses the highly active metal-induced electrolyte decomposition in batteries.
The team used biomass materials as carbon sources to prepare carbon-loaded iodine capsules (ICPC) and found that I3-/I- spontaneous redox can effectively restore dead lithium to compensate for lithium loss. Notably, the deactivated lithium in LiO of dead SEI and deceased lithium metal fragments are transferred to the high-voltage cathode and subsequently recycled to compensate for the loss of lithium, thereby significantly improving the cycle reversibility of lithium metal batteries. The electrochemical performance shows that lithium metal total cells based on limited li ion customized battery packs exhibit ultrahigh performance (1000 cycle life and high Coulombic efficiency of 99.9%); using this strategy to match LiFePO4 (LFP) and LiNi0.8Co0.1Co0.1Mn0 .1O2 (NCM811) and other commercial cathode-assembled button and pouch batteries have shown very encouraging cycle performance and ultra-high efficiency. Therefore, this strategy opens up new avenues for mitigating the capacity fading caused by inactive lithium supply of lithium metal batteries and improving their cycle life, and also for other anode materials challenged by dead SEI and dead lithium, such as silicon, tin, alloys, etc., providing the possibility of large-scale application. Related research results, “Rejuvenating dead lithium supply in lithium metal anodes by iodine redox,” were published in Nature Energy.
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Name: Dawn Zeng (Director)
E-mail address: sales@himaxelectronics.com
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Currently, lithium-ion batteries are used in industrial equipment in various industries. Since there are no fixed custom lithium battery pack specifications and size requirements in various industrial fields. Therefore, there are no conventional lithium batteries for industrial equipment and they all need to be customized. So how long does it take to make li ion customized battery packs?
Under normal conditions, it takes about 15 days to custom lithium battery pack;
Day 1: After receiving the order requirements, the R&D personnel evaluate the order requirements, quote samples and establish customized product projects.
Day 2: Selection and circuit design for product battery cells
Day 3: Make a structural drawing and confirm with the customer, and conduct business negotiations
Day 4: Start material selection, BMS protection board design, battery assembly, cycle charge and discharge, circuit and other tests and debugging verification
Then the packaging, warehousing, quality inspection, outbound delivery, and transportation to the customer are carried out, and the customer conducts sample testing and other work. Under normal circumstances, it takes about 15 working days.
Our lithium battery assembly is not like a small workshop where unknown batteries and BMS protection boards are directly packaged in series and parallel and shipped without testing and verification. This kind of battery is generally a price war. The price of the battery is very low and there is no after-sales guarantee. Basically, it is a one-time business. We will conduct strict testing on all materials, including battery cells, BMS, power harnesses and plugs. All materials must pass the inspection before they can be used to make li ion customized battery packs .
HIMAX is a manufacturer specializing in Li-ion Battery Pack Manufacturing. The batteries are widely used in special equipment, medical equipment, emergency firefighting, security communications, exploration and mapping, instrumentation and other fields. With more than 12 years of manufacturer production experience, Reliable quality.
If you have any question, please feel free to contact us:
Name: Dawn Zeng (Director)
E-mail address: sales@himaxelectronics.com
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The 18650 battery pack has become a popular power solution for a wide range of portable devices,from electronic cigarettes and flashlights to electric vehicles and satellites.
This reliable battery pack offers a high-performance, cost-effective energy solution,making it an excellent choice for a variety of applications.
The 18650 battery, which stands for “18mm diameter and 65mm height,”is a commonly used battery type in the electronics industry.
These batteries have a high energy density and can store a significant amount of power while remaining relatively small in size.
They also have a high discharge rate, allowing them to provide quick bursts of power when needed.
The 18650 battery pack consists of multiple 18650 batteries connected together in a circuit to provide a single power source with a higher total voltage and capacity.
These battery packs are typically designed to be easily installed and used with a variety of devices, providing a reliable source of power for extended use.
The 18650 lithium ion battery pack has several advantages over traditional battery types.
It is highly efficient, providing maximum power output with minimal waste. It is also safe to use, as these batteries are designed with built-in safety features to prevent overcharging, over-discharging, and over-heating. Additionally, the 18650 battery pack is cost-effective, as it can be produced in large quantities at a relatively low cost.
As the use of portable devices continues to grow, the demand for high-quality battery solutions will also increase. It provides a reliable and efficient power source for a wide range of applications, making it an essential component for many electronic devices. Whether it’s used in a flashlight, a drone, or an electric vehicle, the 18650 battery pack has the potential to revolutionize the way we power our portable devices.
If you have any question, please feel free to contact us:
Name: Dawn Zeng (Director)
E-mail address: sales@himaxelectronics.com
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Thank you for your long-term support and trust in Shenzhen Himax Electronics!
We are going to attend HKTDC Hong Kong Electronics Fair (Spring Edition) 2023 at Hong Kong Convention and Exhibition Center in Wanchai, Hong Kong, and we hope to discuss and communicate with you through this opportunity so that we can cooperate more deeply. Together to develop and occupy the market. We sincerely invite you to visit us, we are honored!
Company Name: Shenzhen Himax Electronics Co.
Stand No(s): 5E-A02
Show Dates: 12th-15th April
Venue: Booth 5E-A02, Hall 5th, Hong Kong Convention and Exhibition Center, 1 Expo Dr, Wan Chai, Hong Kong.
Name of Show: HKTDC Hong Kong Electronics Fair (Spring Edition) 2023
We believe this exhibition will bring you a lot of satisfaction, and there will be an extra discount for your order during the show.
Contact: Dawn
TEL: 0452 268 938
E-mail: sales@himaxelectronics.com
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Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. This is why your car battery dies on a cold winter morning, even though it worked fine the previous afternoon. If your batteries spend part of the year shivering in the cold, the reduced capacity has to be taken into account when sizing the system batteries. The standard rating for batteries is at room temperature 25 degrees C (about 77 F). At approximately -22 degrees F (-30 C), battery Ah capacity drops to 50%. At freezing, capacity is reduced by 20%. Capacity is increased at higher temperatures – at 122 degrees F, battery capacity would be about 12% higher.
Wide temperature variations
Battery charging voltage also changes with temperature. It will vary from about 2.74 volts per cell (16.4 volts) at -40 C to 2.3 volts per cell (13.8 volts) at 50 C. This is why you should have temperature compensation on your lead-acid battery charger or charge control if your batteries are outside and/or subject to wide temperature variations.
Internal temperature of a battery
Thermal mass means that because they have so much mass, they will change internal temperature much slower than the surrounding air temperature. A large insulated battery bank may vary as little as 10 degrees over 24 hours internally, even though the air temperature varies from 20 to 70 degrees. For this reason, external (add-on) temperature sensors should be attached to one of the POSITIVE plate terminals, and bundled up a little with some type of insulation on the terminal. The sensor will then read very close to the actual internal battery temperature.
Battery life reduces at higher temperatures
Even though battery capacity at high temperatures is higher, battery life is shortened. Battery capacity is reduced by 50% at -22 degrees F – but battery LIFE increases by about 60%. Battery life is reduced at higher temperatures – for every 15 degrees F over 77, battery life is cut in half. This holds true for ANY type of lead-acid battery, whether sealed, Gel, AGM, industrial or whatever. This is actually not as bad as it seems, as the battery will tend to average out the good and bad times.
One last note on temperatures – in some places that have extremely cold or hot conditions, batteries may be sold locally that are NOT standard electrolyte (acid) strengths. The electrolyte may be stronger (for cold) or weaker (for very hot) climates. In such cases, the specific gravity and the voltages may vary from what we show.
Now we have launched a low temperature battery, HiMASSi Smart & Temp battery, which supports charging at -31 ℉.
Welcome to consult! (sales6@himaxelectronics.com).
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Definition of Series and Parallel Connection of Lithium Batteries
Due to the limited voltage and capacity of the single battery cell, the series and parallel connection is needed in the actual use to obtain higher voltage and capacity, so as to meet the actual power demand of the equipment.
Lithium batteries connected in series
Add the voltage of batteries, capacity remains the same, and internal resistance increases.
Lithium batteries connected in paralle
Constant voltage, added capacity, reduced internal resistance, and extended power supply time.
Lithium batteries connected in series and parallel
3.7V single battery can be assembled into battery pack with a voltage of 3.7*(N)V as required (N: number of single batteries)
For example, 7.4V, 12V, 24V, 36V, 48V, 60V, 72V, etc.
Capacity of Parallel Connection
2000mAh single battery can be assembled into a battery pack with capacity of 2*(N)Ah as required (N: number of single batteries)
For example, 4000mAh, 6000mAh, 8000mAh,5Ah, 10Ah, 20Ah, 30Ah, 50Ah, 100Ah, etc.
Lithium Battery Pack
Lithium battery pack technique refers to the processing, assembly and packaging of lithium battery pack. The process of assembling lithium cells together is called PACK, which can be a single battery or a lithium battery pack connected in series or parallel. The lithium battery pack usually consists of a plastic case, PCM, cell, output electrode, bonding sheet, and other insulating tape, double-coating tape, etc.
Lithium cell: The core of a finished battery
PCM: Protection functions of over charge, over discharge, over current, short circuit, NTC intelligent temperature control.
Plastic case: the supporting skeleton of the entire battery; Position and fix the PCM; Carry all other non-case parts and limit.
Terminal lead: It can provide a variety of terminal wire charging and discharging interface for a variety of electronic products, energy storage products and backup power.
Nickel sheet/bracket: Connection and fixing component of the cell
Lithium Battery Series and Parallel Connection
Due to security reasons, lithium ion batteries need an external PCM used for battery monitoring for each battery. It is not recommended to use batteries in parallel. If connect in parallel, make sure the consistency of the battery parameters (capacity, internal resistance, etc.), the other batteries in series need to have consistent parameters, otherwise, the performance of the battery pack can be much worse than the performance of a single cell.
The purpose of lithium battery matching is to ensure that every cell in the battery has consistent capacity, voltage and internal impedance, because inconsistent performances will make lithium battery have various parameters during using. Voltage imbalance will happen. After a long run, the battery will overcharge, over discharge, capacity lost, or even fire to explode.
1.Series and Parallel Connection Mode of Lithium Battery
The length of the plug and lead of the lithium battery pack can be customized according to the customer’s electrical equipment.
3.Calculation Lithium Battery Connected in Series and Parallel
We all know that lithium battery voltage increases after series connection, capacity increases after parallel connection, then how to calculate a lithium battery quantity of series or parallel connection, and how many cells?
Before the calculation, we need to know which cell specification of the battery pack is adopted for the assembly, because different cells have different voltage and capacity. The cell quantity of series and parallel connection required to assemble a specific lithium battery pack varies. The common lithium cell types on the market are: 3.7V LiCoO2, 3.6V ternary, 3.2V LFePO4, 2.4V lithium titanate. The capacity is different because of the cell size, material and manufacturers.
Take 48V 20Ah Lithium Battery Pack for Example
Suppose the size of the single cell used is 18650 3.7V 2000mAh
Cell quantity of series connection: 48V/3.7V=12.97. That is 13 cells in series.
Cell quantity of parallel connection: 20Ah/2Ah=10. That is 10 cells in parallel.
18650-3S6P/11.1V/15600mAh Lithium Battery Assembly Process
Cell Capacity Grading
Capacity Difference≤30mAh
After capacity grading, stay still for 48-72h and then distribute.
Voltage Internal Impedance Sorting and Matching
Voltage Difference≤5mV
Internal Impedance Difference≤5mΩ 8 cells with similar voltage internal impedance are distributed together.
Cell Spot Welding
The use of formed nickel strip eliminates the problems of spurious joint, short circuit, low efficiency and uneven current distribution
Welded PCM
Make sure that the circuit board has no leakage components, and the components have no defective welding.
Battery Insulation
Paste the fibre, silicone polyester tape for insulation.
Battery Pack Aging
For the quality of the battery, improve the stability, safety and service life of the lithium battery.
PVC Shrink Film
Position the two ends after heat shrinking,
then heat shrink the middle part.
Put PVC film in the middle. No whiten after stretching. No hole.
Finished Product Performance Test
Voltage：10.8～11.7V
Internal Impedance：≤150mΩ
Charge-discharge and overcurrent performance test.
Battery Code-spurting
Code-spurting cannot be skewed, and it needs legible handwriting
Precautions for Lithium Batteries in Series and Parallel
Don’t use batteries with different brands together.
Do not use batteries with different voltages together.
Do not use different capacities or old and new lithium batteries together.
Batteries with different chemical materials cannot be used together, such as nickel metal hydride and lithium batteries.
Replace all batteries when electricity is scarce.
Use the lithium battery PCM with corresponding parameters.
Choose batteries with consistent performance. Generally, distributing of lithium battery cells is required for series and parallel connection. Matching standards: voltage difference≤10mV, impedance difference ≤5mΩ, capacity difference ≤20mA
1.Lithium Battery With Different Voltage Connected in Series
Due to the consistency issue of lithium batteries, when the same system (such as ternary or lithium iron) is used for series or parallel connection, it is also necessary to select the batteries with the same voltage, internal impedance and capacity for matching. Batteries with different voltage platforms and different internal impedance used in series will cause a certain battery to be fully charged and discharged first in each cycle. If there is a PCM and no fault occurs, the capacity of the whole battery will be reduced. If there is no PCM, the battery will be overcharged or over discharged, which will damage the battery.
2.Lithium Batteries With Different Capacities Connected in Parallel
If different capacities or old and new lithium batteries are used together, there may be leakage, zero voltage and other issues, because during the charging process, capacity differences make some batteries overcharge, some batteries not, while during discharge process, high capacity batteries do not run out of power, but low capacity batteries over discharge. In such a vicious cycle, the batteries will be damaged by leakage or low (zero) voltage.
To assemble lithium batteries, connect them in parallel or in series first?
Topological Structure of Lithium Battery Connected in Series and Parallel
The typical connection modes of a lithium battery pack are connecting first in parallel and then in series, first in series and then in parallel, and finally, mixing together.
Lithium battery pack for pure electric buses is usually connected first in parallel and then in series.
Lithium battery pack for power grid energy storage is tend to be connected first in series and then in parallel.
First Parallel and Then Series of Power Battery Module Topological Structure
First Series and Then Parallel of Power Battery Module Topological Structure
First Parallel, Then Series and Parallel Again of Power Battery Module Topological Structure
Advantages of Lithium Batteries First Connected in Parallel and Then in Series
If a lithium battery cell automatically exits, except the capacity reduction, it does not affect parallel connection;
In parallel connection, a short circuit of a lithium battery cell may cause short circuit due to large current, which is usually avoided by using fuse protection technology.
Disadvantages of Lithium Batteries First Connected in Parallel and Then in Series
If a lithium battery cell automatically exits, except the capacity reduction, it does not affect parallel connection;
In parallel connection, a short circuit of a lithium battery cell may cause short circuit due to large current, which is usually avoided by using fuse protection technology.
Advantages of Lithium Batteries First Connected in Series and Then in Parallel
First connecting the batteries in series according to the capacity, for example, 1/3 of the whole battery capacity are connected in series, and then connecting the rest in parallel, will reduce the failure probability of high-capacity lithium battery modules. First series and then parallel connection help the consistency of the lithium battery pack.
From the perspective of the reliability of the lithium battery connection, the development trend of voltage inconsistency and the influence of performance, the connection mode of first parallel and then series is better than that of first series and then parallel, and the topology structure of first series and then parallel lithium battery is conducive to the detection and management of each lithium battery cell in the system.
Lithium Batteries Charging in Series and Parallel
1.Charging Lithium Batteries In Series
At present, lithium battery tends to be charged in series, which is mainly due to its simple structure, low cost and easy realization. But as a result of different capacity, internal impedance, aging characteristics and self-discharge performance, when charge lithium battery in series, battery cell with the smallest capacity will be fully charged first, and at this point, the other battery cell is not full of electricity. If continue to charge in series, the fully charged battery cell may be overcharge.
Lithium Battery overcharge will damage the battery performance, and even lead to explosion and injuries, therefore, to prevent battery cell overcharging, lithium battery has equipped with Battery Management System (BMS). The Battery Management System has overcharge protection for every single lithium battery cell, etc. When charging in series, if the voltage of a single lithium battery cell reaches the overcharge protection voltage, the battery management system will cut off the whole series charging circuit and stop charging to prevent the single lithium battery cell from being overcharged, which will cause other lithium batteries unable to be fully charged.
2.Charging Lithium Batteries In Parallel
In parallel charging of lithium batteries, each lithium ion battery needs equalizing charge, otherwise, the performance and life of the whole lithium ion battery pack will be affected. Common charging equalization technologies include: constant shunt resistance equalizing charge, on-off shunt resistance equalizing charge, average battery voltage equalizing charge, switch capacitor equalizing charge, step-down converter equalizing charge, inductance equalizing charge, etc.
Several problems need to be paid attention to in parallel charging of lithium batteries：
Lithium batteries with and without PCM cannot be charged in parallel. Batteries without PCM can easily be damaged by overcharging.
Batteries charged in parallel usually need to remove the built-in PCM of the battery and use a unified battery PCM.
If there is no PCM in parallel charging battery, the charging voltage must be limited to 4.2V and 5V charger cannot be used.
After lithium ion batteries connecting in parallel, there will be a charging protection chip for lithium battery charging protection. Lithium battery manufacturers have fully considered the change characteristics of lithium battery in parallel before battery production. The above requirement of current design and choice of batteries are very important, so that users need to follow the instructions of parallel lithium batteries charging step by step, so as to avoid the possible damage for incorrect charge.
3.Notes for Lithium Battery Charging
Special charger must be used for lithium battery, or battery may not reach saturation state, affecting its performance.
Before charging the lithium battery, it does not need to discharge completely.
Do not keep the charger on the socket for a long time. Remove the charger as soon as the battery fully charged.
Batteries shall be taken out of electric appliances that have not been used for a long time and stored after they are fully discharged.
Do not plug the anode and cathode of the battery into the opposite direction, otherwise, the battery will swell or burst.
Nickel charger and lithium charger cannot be used together.
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Know how to apply an equalize charge and not damage the battery.
Stationary batteries are almost exclusively lead acid and some maintenance is required, one of which is equalizing charge. Applying a periodic equalizing charge brings all cells to similar levels by increasing the voltage to 2.50V/cell, or 10 percent higher than the recommended charge voltage.
An equalizing charge is nothing more than a deliberate overcharge to remove sulfate crystals that build up on the plates over time. Left unchecked, sulfation can reduce the overall capacity of the battery and render the battery unserviceable in extreme cases. An equalizing charge also reverses acid stratification, a condition where acid concentration is greater at the bottom of the battery than at the top.
Experts recommend equalizing services once a month to once or twice a year. A better method is to apply a fully saturated charge and then compare the specific gravity readings (SG) on the individual cells of a flooded lead acid battery with a hydrometer. Only apply equalization if the SG difference between the cells is 0.030.
During equalizing charge, check the changes in the SG reading every hour and disconnect the charge when the gravity no longer rises. This is the time when no further improvement is possible and a continued charge would have a negative effect on the battery.
The battery must be kept cool and under close observation for unusual heat rise and excessive venting. Some venting is normal and the hydrogen emitted is highly flammable. The battery room must have good ventilation as the hydrogen gas becomes explosive at a concentration of 4 percent.
Equalizing VRLA and other sealed batteries involves guesswork. Observing the differences in cell voltage does not give a conclusive solution and good judgment plays a pivotal role when estimating the frequency and duration of the service. Some manufacturers recommend monthly equalizations for 2–16 hours. Most VRLAs vent at 34kPa (5psi), and repeated venting leads to the depletion of the electrolyte, which can lead to a dry-out condition.
Not all chargers feature equalizing charge. If not available, the service should be performed with a dedicated device.
https://himaxelectronics.com/wp-content/uploads/2021/10/Equalizing-Charge.jpg300514administrator/wp-content/uploads/2019/05/Himax-home-page-design-logo-z.pngadministrator2021-10-12 03:52:572024-04-28 15:31:14What is Equalizing Charge?
