Li-polumer-battery

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.

Custom Lithium Battery Pack

 

 

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.

If you have any question, please feel free to contact us:

  • Name: Dawn Zeng (Director)
  • E-mail address: sales@himaxelectronics.com
Himax - Lifepo4-Battery-9.6V

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.

Li Ion Customized Battery Packs

 

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.

If you have any question, please feel free to contact us:

  • Name: Dawn Zeng (Director)
  • E-mail address: sales@himaxelectronics.com

 

 

Himax - 14.8v-2500mAh 18650 battery pack

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.

Li Ion Customized Battery Packs

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
Himax Decorative Pictures - battery pro

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.

18650 Battery Pack

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

A Letter to Battery Lovers

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

Himax Battery

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

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.

Low Temperature Battery

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).

 

Himax 12v-batteries-in-parallel

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,5Ah10Ah20Ah, 30Ah, 50Ah100Ah, 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 Pack Structure

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.

Lithium Battery Series and Parallel Connection

Lithium battery matching criteria
voltage difference ≤ 10 mv, impedance difference ≤ 5 mΩ, capacity difference ≤20mA

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.

Two Lithium Batteries Connected in Series (7.4V Lithium Battery)

Two Lithium Batteries Connected in Series
model 18650-2S1P 18650-2S1P 18650-2S2P 18650-2S3P
Voltage 7.4V 7.4V 7.4V 7.4V
Capacity 2200/2500/3000mAh 2200/2500/3000mAh 6000mAh 9000mAh
Dimension 18*105mm 18*36*65mm 37*37*66mm 37*55*66mm
Weight 90g 90g 180g 270g

Three Lithium Batteries Connected in Series (11.1V Lithium Battery)

Three Lithium Batteries Connected in Series
Series and Parallel Connection Mode 18650-3S1 P triangle 18650-3S1P in-line 18650-3S2P 18650-3S3P
Voltage 11.1V 11.1V 11.1V 11.1V
Capacity 2200/2500/3000mAh 2200/2500/3000mAh 6000mAh 9000mAh
Dimension 66.5*36.6*36.6mm 69.8*55.7*18.8mm 66.8*55.0*40.8mm 60.6*68.0*56.1mm
Weight 155g 158g 285g 425g

Four Lithium Batteries Connected in Series (14.8V Lithium Battery)

Four Lithium Batteries Connected in Series
Series and Parallel Connection Mode 18650-4S1P square 18650-4S1P In-line 18650-4S2P
Voltage 14.8V 14.8V 14.8V
Capacity 2200/2500/3000mAh 2200/2500/3000mAh 6000mAh
Dimension 69.6*37.7*37.7mm 69.3*73.4*17.6mm 70.6*74.2*37.1mm
Weight 181g 191g 371g

Six Lithium Batteries Connected in Series (22.2V Lithium Battery)

Six Lithium Batteries Connected in Series
Series and Parallel Connection Mode 18650-6S1P In-line 18650-6S2P 18650-6S3P
Voltage 25.2V 25.2V 25.2V
Capacity 2000/3000mAh 6000mAh 9000mAh
Dimension 114*72*22mm 114*72*41mm 114*72*60mm
Weight 303g 570g 835g

The length of the plug and lead of the lithium battery pack can be customized according to the customer’s electrical equipment.

Lithium Battery Wire/Terminal

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.

Commonly Used Lithium Battery Connected in series

Nominal Voltage Battery Category Common Quantity of series connection Charging Voltage
12V 3.7V LiCoO2 3S 12.6V
3.2V LiFePO4 4S 14.6V
24V 3.7V LiCoO2 7S 29.4V
3.2V LiFePO4 8S 29.2V
36V 3.7V LiCoO2 10S 42.0V
3.7V LiCoO2 11S 46.2V
3.2V LiFePO4 11S 40.2V
3.2V LiFePO4 12S 43.8V
48V 3.7V LiCoO2 13S 54.6V
3.7V LiCoO2 14S 58.8V
3.2V LiFePO4 15S 58.8V
3.2V LiFePO4 16S 58.8V
60V 3.7V LiCoO2 17S 71.4V
3.2V LiFePO4 20S 73.0V
72V 3.7V LiCoO2 20S 84.0V
3.2V LiFePO4 24S 87.6V

Lithium Battery Assembly Process

18650-3S6P/11.1V/15600mAh Lithium Battery Assembly Process

  • Cell Capacity Grading

    Cell Capacity Grading

    Capacity Difference≤30mAh
    After capacity grading, stay still for 48-72h and then distribute.

  • Voltage Internal Impedance Sorting and Matching

    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

    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

    Welded PCM

    Make sure that the circuit board has no leakage components, and the components have no defective welding.

  • Battery Insulation

    Battery Insulation

    Paste the fibre, silicone polyester tape for insulation.

  • Battery Pack Aging

    Battery Pack Aging

    For the quality of the battery, improve the stability, safety and service life of the lithium battery.

  • PVC Shrink Film

    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

    Finished Product Performance Test

    Voltage:10.8~11.7V
    Internal Impedance:≤150mΩ
    Charge-discharge and overcurrent performance test.

  • Battery Code-spurting

    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

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.

Full voltage not available

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.

Full Capacity not available

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 Parallel and Then Series of Power Battery Module Topological Structure
First Series and Then Parallel 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
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

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.

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.

  • 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.
Himax - What is Equalizing Charge?

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.

Himax - What is Equalizing Charge?

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.

Himax - How to Awaken a Sleeping Li-ion

Learn what you can do to prevent a Li-ion battery to fall asleep.

Li-ion batteries contain a protection circuit that shields the battery against abuse. This important safeguard also turns the battery off and makes it unusable if over-discharged. Slipping into sleep mode can happen when storing a Li-ion pack in a discharged state for any length of time as self-discharge would gradually deplete the remaining charge. Depending on the manufacturer, the protection circuit of a Li-ion cuts off between 2.2 and 2.9V/cell.

Some battery chargers and analyzers (including Cadex), feature a wake-up feature or “boost” to reactivate and recharge batteries that have fallen asleep. Without this provision, a charger renders these batteries unserviceable and the packs would be discarded. Boost applies a small charge current to activate the protection circuit and if a correct cell voltage can be reached, the charger starts a normal charge. Figure 1 illustrates the “boost” function graphically.

booost1.jpg

Figure 1: Sleep mode of a lithium-ion battery.

Some over-discharged batteries can be “boosted” to life again. Discard the pack if the voltage does not rise to a normal level within a minute while on boost.

Do not boost lithium-based batteries back to life that have dwelled below 1.5V/cell for a week or longer. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. When recharging, such a cell might become unstable, causing excessive heat or show other anomalies. The Cadex “boost” function halts the charge if the voltage does not rise normally.

When boosting a battery, assure correct polarity. Advanced chargers and battery analyzers will not service a battery if placed in reverse polarity. A sleeping Li-ion does not reveal the voltage, and boosting must be done with awareness. Li-ion is more delicate than other systems and a voltage applied in reverse can cause permanent damage.

Storing lithium-ion batteries presents some uncertainty. On one end, manufacturers recommend keeping them at a state-of-charge of 40–50 percent, and on the other end there is the worry of losing them due to over-discharge. There is ample bandwidth between these criteria and if in doubt, keep the battery at a higher charge in a cool place.

Cadex examined 294 mobile phones batteries that were returned under warranty. The Cadex analyzer restored 91 percent to a capacity of 80 percent and higher; 30 percent were inactive and needed a boost, and 9 percent were non-serviceable. All restored packs were returned to service and performed flawlessly. This study shows the large number of mobile phone batteries that fail due to over-discharging and can be salvaged.

 

Himax - Cost of Mobile and Renewable Power

Compare battery energy with fossil fuel and other resources

Lifting off in a large airplane is exhilarating. At a full weight of almost 400 tons, the Boeing 747 requires 90 megawatts of power to get airborne. Take-off is the most demanding part of a flight and when reaching cruising altitude the power consumption decreases to roughly half.

Powerful engines were also used to propel the mighty Queen Mary that was launched in 1934. The 81,000-ton ocean liner measuring 300 meters (1,000ft) in length was powered by four steam turbines producing a total power of 160,000hp (120 megawatts). The ship carried 3,000 people and traveled at a speed of 28.5 knots (52km/h). Queen Mary is now a museum in Long Beach, California.

Table 1 illustrates man’s inventiveness in the quest for power by comparing an ox of prehistoric times with newer energy sources made available during the Industrial Revolution to today’s super engines, with seemingly unlimited power.

SINCE TYPE OF POWER SOURCE GENERATED POWER
3000 BC Ox pulling a load 0.5hp 370W
350 BC Vertical waterwheel 3hp 2,230W
1800 Watt’s steam engine 40hp 30kW
1837 Marine steam engine 750hp 560kW
1900 Rail steam engine 12,000hp 8,950kW
1936 Queen Mary ocean liner 160,000hp 120,000kW
1949 Cadillac car 160hp 120kW
1969 Boeing 747 jet airplane 100,000hp 74,600kW
1974 Nuclear power plant 1,520,000hp 1,133,000kW

Table 1: Ancient and modern power sources

Large propulsion systems are only feasible with the internal combustion engines (ICE), and fossil fuel serves as a cheap and plentiful energy resource. Low energy-to-weight ratio in terms of net calorific value (NCV) puts the battery against the mighty ICE like David and Goliath. The battery is the weaker vessel and is sensitive to extreme heat and cold; it also has a relatively short life span.

While fossil fuel delivers an NCV of 12,000Wh/kg, Li-ion provides only between 70Wh/kg and 260Wh/kg depending on chemistry; less with most other systems. Even at a low efficiency of about 30 percent, the ICE outperforms the best battery in terms of energy-to-weight ratio. The battery capacity would need to increase 20-fold before it could compete head-to-head with fossil fuel.

Another limitation of battery propulsion over fossil fuel is fuel by weight. While the weight diminishes when being consumed, the battery carries the same deadweight whether fully charged or empty. This puts limitations on EV driving distance and would make the electric airplane impractical. Furthermore, the ICE delivers full power at freezing temperatures, runs in hot climates, and continues to perform well with advancing age. This is not the case with a battery as each subsequent discharge delivers slightly less energy than the previous cycle.

Power from Primary Batteries

Energy from a non-rechargeable battery is one of the most expensive forms of electrical supply in terms of cost per kilowatt-hours (kWh). Primary batteries are used for low-power applications such as wristwatches, remote controls, electric keys and children’s toys. Military in combat, light beacons and remote repeater stations also use primaries because charging is not practical. Table 2 estimates the capability and cost per kWh of primary batteries.

AAA CELL AA CELL C CELL D CELL 9 VOLT
Capacity (alkaline) 1,150mAh 2,850mAh 7,800mAh 17,000mAh 570mAh
Energy (single cell) 1.725Wh 4.275Wh 11.7Wh 25.5Wh 5.13Wh
Cost per cell (US$) $1.00 $0.75 $2.00 $2.00 $3.00
Cost per kWh (US$) $580 $175 $170 $78 $585

Table 2: Capacity and cost comparison of primary alkaline cells. One-time use makes energy stored in primary batteries expensive; cost decreases with larger battery size.

Power from Secondary Batteries

Electric energy from rechargeable batteries is more economical than with primaries, however, the cost per kWh is not complete without examining the total cost of ownership. This includes cost per cycle, longevity, eventual replacement and disposal. Table 3 compares Lead acid, NiCd, NiMH and Li-ion.

LEAD ACID NICD NIMH LI ION
Specific energy (Wh/kg) 30–50 45–80 60–120 100–250
Cycle life Moderate High High High
Temperature performance Low when cold -50°C to 70°C Reduced when cold Low when cold
Applications UPS with infrequent discharges Rugged, high/low temperature HEV, UPS with frequent discharges EV, UPS with frequent discharges
Cost per kWh ($US)
Load leveling, powertrain
$100-200 $300-600 $300-600 $300–1,000

Table 3: Energy and cost comparison of rechargeable batteries. Although Li-ion is more expensive than Lead acid, the cycle cost may be less. NiCd operates at extreme temperatures, has the best cycle life and accepts ultra-fast charge with little stress.

 

Power from Other Sources

To reduce the fossil fuel consumption and to lower emissions, governments and the private sector are studying alternate energy sources. Table 4 compares the cost to generate 1kW of power that includes initial investment, fuel consumption, maintenance and eventual replacement.

Fuel type Equipment
to generate 1kW
Life span Cost of fuel
per kWh
Total cost
per kWh
Li-ion
Powertrain
$500/kW (20kW battery
costing $10,000)
2,500h (repl. cost $0.40/kW) $0.20 $0.60
($0.40 + $0.20)
ICE in vehicle $30/kW
($3,000/100kW)
4,000h (repl. cost $0.01/kW) $0.33 $0.34
($0.33 + $0.01)
Fuel cell
– portable
– mobile
– stationary
$3,000–7,500 2,000h
4,000h
40,000h
$0.35
->
->
->
$1.85 – 4.10
$1.10 – 2.25
$0.45 – 0.55
Solar cell $12,000, 5kW system 25 years $0 ~$0.10*
Electricity
electric grid
All inclusive All inclusive $0.20
(average)
$0.20

Table 4: Cost of generating 1kW of energy. Estimations include the initial investment, fuel consumption, maintenance and replacement of the equipment. Grid electricity is lowest.

* Amortization of investment yielding 200 days of 5h/day sun; declining output with age not included.

Power from the electrical utility grid is most cost-effective. Consumers pay between $0.06 and $0.40US per kWh, delivered with no added maintenance cost or the need to replace aging power-generating machinery; the supply is continuous. (The typical daily energy consumption per household in the West is 25kW.)

The supply of cheap electricity changes when energy must be stored in a battery, as is the case with a solar system that is backed up by a battery and in the electric powertrain. High battery cost and a relatively short life can double the electrical cost if supplied by a battery. Gasoline (and equivalent) is the most economical solution for mobility.

The fuel cell is most effective in converting fuel to electricity, but high equipment costs make this power source expensive in terms of cost per kWh. In virtually all applications, power from the fuel cell is considerably more expensive than from conventional methods.

Our bodies also consume energy, and an active man requires 3,500 calories per day to stay fit. This relates to roughly 4,000 watts in a 24-hour day (1 food Calorie* = 1.16 watt-hour). Walking propels a person about 40km (25 miles) per day, and a bicycle increases the distance by a factor of four to 160km (100 miles). Eating two potatoes and a sausage for lunch propels a bicyclist for the afternoon, covering 60km (37 miles, a past-time activity I often do. Not all energy goes to the muscles alone; the brain consumes about 20 percent of our intake. The human body is amazingly efficient in converting food to energy; one would think that the potato and sausage lunch could hardly keep a laptop going for that long. Table 5 provides the stored energies of calories, proteins and fat in watt-hours and joules.