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What is The Industrial Battery System?

What is an industrial battery?

Batteries for industrial applications have certain characteristics, such as high discharge and large capacity. These batteries consist of three parts: Customized battery + BMS + Charging system

Industrial applications

Let’s look at where industrial batteries are used. Industrial applications cover a wide area, but we can separate them into 3 larger categories:

– Measuring, Mapping and Surveying equipment

– Detection and Inspection equipment

– Filming and Production equipment

In these three industrial areas, the batteries must be adjusted according to their different use.

For example, in areas with extremely cold temperatures, the batteries should have the ability to withstand low temperatures and continue to discharge at low temperatures all while fulfilling the charging capabilities. If a device can be charged in these extreme environments, users can save time and the cost that it takes to remove and replace a battery or device in these settings. This can increase the overall efficiency.

Why are industrial batteries needed?

Technically, not all industrial applications require industrial batteries. However, they are the preferred norm as a complete power system will ensure that a customer’s equipment maintains sufficient power without causing any delays or decreasing inefficiency due to power problems.

The BMS

A BMS (Battery Management System) is the intelligent component of a battery pack that is responsible for advanced monitoring and management. It plays a critical role in safety, performance, charge rates, and longevity. By monitoring the SOC (State of Charge) of the battery and managing the charge and discharge, the BMS can overall increase the efficiency and life of the battery.

Major functions of the BMS:

Overcharge protection
Over-discharge protection
Overcurrent protection
Overheat protection
Short-circuit protection
Cell monitoring & balancing
Communication interface
Self-diagnosis
Power gauge

Customized batteries

It is impossible for one battery to fit all the different industrial applications. Its voltage, capacity, and discharge current may easily meet the requirements of one device, but its size, internal resistance, temperature range, charging rate, and may not meet the requirements of another device. It is for this reason that industrial batteries must be customized. Take a forklift that must operate a cold storage warehouse or facility. Let’s say that the ambient temperature at which the forklift works in such an environment is -10℃ to -40℃.

At this point, one must ask: Can the battery powering the forklift discharge at -40℃? Can the discharge current start the forklift? How long can the battery keep supplying power? Mor importantly, how long does the forklift work?

Forklifts working in cold storage facilities generally need to be driven to a separate room with normal temperatures for charging. This is because a Lithium battery’s charging performance below 0 degrees is extremely poor, and the battery may pose a safety hazard. When the battery returns to normal temperatures, moisture can generate on the surface. If the battery is also used or stored in an environment with high humidity for a long time, the battery cells will corrode and affect the battery life.

Himax low-temperature LiPo battery charge curved

On the other hand, if the battery has been customized to work in low-temperature environments, then the battery will be able to be charged in the cold storage facility without having to go through the hassle of moving the forklift to another space. This will overall increase efficiency and save on costs, which is why a customized battery is important for industrial applications.

The charging system

In general, the power of industrial battery chargers is relatively large; after all, the voltage and capacity of industrial batteries are relatively large, but the essentials of industrial battery chargers are to create synergistic effects with industrial batteries.

Industrial batteries are biased towards customized energy solutions, so chargers need to be able to detect the state of the battery to provide the highest quality charging solution, such as determining its own charging cycle rate to adjust the charging current based on the battery’s discharge state. Through the BMS, the charger can detect whether the battery has an abnormal voltage gap and remind the user that the battery needs to be replaced. Fail-safe designs also protect the battery and device when the state of charge is abnormal.

Advantages of an industrial battery system

The profitability of the manufacturing industry is constantly in a state of flux. Therefore, capacity and cost control are particularly important, and cost reduction will help factories have a greater advantage in profitability and bargaining power. Being able to achieve this goal allows these companies to maintain their profitability despite the rise and fall of commodity prices. If you want to learn more about industrial batteries, please contact us.

June 23, 2020

Li-Polymer Battery, LifePO4 Battery, News

A LiFePO4 Battery Vs Lithium Ion Polymer Battery

The cycle life of a Lithium iron phosphate (LiFePO4) battery is more than 4 to 5 times that of other lithium ion polymer batteries. The operating temperature range is wider and safer; however, the discharge platform is lower, the nominal voltage is only 3.2V, and the fully-charged voltage is 3.65V.

Lithium iron phosphate is mostly used to replace traditional lead-acid batteries. We also often find that lithium iron phosphate batteries are used in household solar energy systems, fishing, golf carts, outdoor portable energy storages, and electric motorcycles.

What is a Lithium iron phosphate battery?

Lithium-ion polymer (LIPO) battery

A lithium ion polymer battery is a kind of rechargeable battery that mainly relies on the movement of lithium ions between positive electrode and negative electrode to work. Lithium ion batteries use an intercalated lithium compound as an electrode material. At present, the commonly used cathode materials for lithium ion batteries are: lithium cobalt oxide (LCO battery), lithium manganate (LMO battery), lithium-ion ternary (NCA, NMC battery), and lithium iron phosphate (LiFePO4 battery).

Lithium iron phosphate (LiFePO4, LFP) battery

A lithium iron phosphate battery is a type of lithium ion polymer battery that uses LiFePO4 as the cathode material and a graphitic carbon electrode with a metallic backing as the anode.

The LiFePO4 battery, also called the LFP battery, is a type of rechargeable battery. It is the safest Lithium battery type currently available on the market today. It is made to be small in size and light in weight, and the cycle life can reach thousands of cycles.

The difference between LiFePO4 batteries and other li-ion batteries

Inherited some advantages from Lithium-ion batteries

Large current charging and discharging are one of the advantages of LiPo batteries, which allows a device to release more energy in a short period of time. These batteries are used more in racing and power tools: almost all drones and RC model batteries use lithium ion batteries.

Batteries for RC models normally reach 15C, 30C, 50C discharge. Lithium-ion polymer batteries with high discharge rate can reach a maximum of 50C (continuous) and 150C (pulse). They are light in weight, have a long life, and can be manufactured into various shapes. These are just some of the advantages of lithium ion batteries, and lithium iron phosphate batteries have these advantages.

Long cycle life

Because a LFP battery’s cycle life is 4 to 5 times that of other lithium ion batteries, it can reach 2000 to 3000 cycles or more. The LiFePO4 battery can also reach 100% depth of discharge (DOD). This means that, for energy storage products, there is no need to worry about over discharging a LFP battery, and it can even be used for a longer period of time. A good LiFePO4 battery can be used for 3 to 7 years, so the average cost is very affordable.

For more content on depth of discharge (DOD), you can read this article: What is DOD for LiFePO4 batteries?

However, a LiFePO4 battery is not suitable for wearable devices as its energy density is lower than that of other lithium-ion batteries. Furthermore, the battery compartment has limited space, so the capacity is relatively lower.

Thus, compared to another LiPo battery, a LFP battery does not have quite as good endurance and compatibility with the conditions and internal space of wearable devices.

Why are most lithium iron phosphate batteries 12V?

It is said that the lithium iron phosphate battery can perfectly replace the lead-acid battery. The nominal voltage of a lead-acid battery is 2V, and the six lead-acid batteries connected in series are 12V.

However, the 12V LiFePO4 battery pack is generally composed of 4 battery cells connected in series. The nominal voltage of a single lithium iron phosphate pouch cell is 3.2V. When adding the voltage of the series, we get 12.8V (3.2V * 4 = 12.8V). There are also the 24V (25.6V) and 48V (51.2V), which are commonly used.

In addition, the voltage requirement of most industrial applications is 12V or above, which is also the minimum standard of the nominal voltage of general industrial batteries. There are also many applications that need to reach 220V, even 380V or above, such as an industrial forklift, winch, electric drill, etc.

The sales of 24V and 48V electric forklifts are on the rise especially recently, so a primary concern is over how safe a battery is. Compared to the lithium cobalt oxide and lithium manganese oxide batteries, lithium iron phosphate batteries are a lot more safe. The advantage of high life can reduce the whole costs of maintaining and replacing the battery as well.

The shortcomings of cold temperature

Compared to other LiPo and lead-acid batteries, lithium iron phosphate batteries have poor resistance in low-temperature environments; generally, they can only discharge at -10℃ to -20℃.

However, clients think positively of LFP batteries and their high safety functions. They sacrifice some battery performance and specify that they discharge at -30℃ to -40℃. These batteries are mostly used in the military or deep sea and space equipment.

Learn more about batteries

Keep an eye out on Himax’s official blog, where we regularly update industry-related articles to keep you up-to-date.

June 23, 2020

News

How to Maintain a GPS Lithium Battery?

At present, most vehicle GPS on the market is powered by a built-in lithium battery, this power supply method is suitable for many portable digital products. Lithium-ion batteries have the advantages of stable discharge performance, high energy density, small size, and no memory effect.

Vehicle GPS as one of the main products using lithium batteries, in the daily use of GPS, many bad usage habits can cause fatal damage to lithium batteries in-vehicle GPS systems. Since lithium batteries have special requirements in terms of use and daily maintenance when using lithium batteries as a power supply method, we should pay attention to the following:

Many users are accustomed to plugging in the GPS charger when using vehicle GPS, the car’s power supply will automatically charge the GPS batteries, so each time the GPS system is turned on or off is equivalent to charging and discharging the batteries, which will affect the battery life.

Since the main factor that affects the life and capacity of lithium batteries is the number of times the battery is charged and discharged, that’s why the GPS battery in vehicles has become less durable.

The correct use method is to charge the battery when the GPS power is low, and then disconnect the charger after the GPS is fully charged. It should be noted that the GPS battery would be at an over-discharged state by its self-discharge characteristics in case the GPS is not used for a long time. In order to prevent over-discharge, the GPS battery should be charged periodically every month.

The battery capacity of the newly purchased GPS is only 50% or lower, and it can be used normally for the first time. When the battery capacity is insufficient, it should be charged normally according to the instructions of the manual. It is best to use the original charger for charging.

In addition, there are several points to be noted during the use of GPS:

Don’t over-charge and over-discharge the GPS battery. Charging normally when the battery capacity is low, which will not damage the lithium battery.
Use the original charger for charging, don’t use a third-party charger.
Most car GPS lithium batteries are built-in, don’t disassemble or modify the battery without permission.
Avoid exposing the product to extreme environments and protect the battery from liquid corrosion.

In fact, the reasonable and correct use of lithium batteries, and proper maintenance, vehicle GPS service life will be extended according to the battery life.

June 16, 2020

News, Ni-Mh Battery

Do NiMH Batteries Explode?

Compared to a lithium ion polymer (LiPo) battery, the nickel-metal hydride (NiMH) battery is a relatively safe battery as it is well designed in terms of safety performance due to its material and structure.

Generally, the NiMH rechargeable batteries rarely leak, unlike alkaline batteries. However, both alkaline and rechargeable batteries contain electrolytes, which could induce leakage when the batteries are used incorrectly.

By this logic, nickel-metal hydride batteries may explode. The principle of explosion is that the air pressure inside an object becomes too large, so the container cannot be contained. When the container breaks, it results in an explosion as the air pressure is released in an instant.

If a battery is used improperly, there can be an overcharge/discharge, short circuit, and even increase in internal voltage. To prevent the battery from exploding, a recoverable safety valve will open and reduce the internal pressure, thereby preventing an explosion.

What are NiMh batteries?

The nickel-metal hydride battery is mostly used in mobile-communication equipment, power tools, and medical equipment.

NiMH batteries are divided into high-voltage and low-voltage batteries. The high-voltage NiMH battery was first developed by M.Klein and J.F. Stockel in the United States in the early 1970s. Since then, there has been a tendency to replace nickel-cadmium with nickel-metal hydride batteries.

The positive electrode active material of Ni-MH battery is Ni (OH) 2 (called NiO electrode), the negative electrode active material is metal hydride, also called hydrogen storage alloy (the electrode is called hydrogen storage electrode), and the electrolyte is 6 mol/L potassium hydroxide solution.

The batteries are produced by different methods according to how they will be used. Different methods include the sintering, pulping, foam-nickel, fiber-nickel, and infiltration process.

Many batteries use the slurry-pulled negative electrode and the foamed nickel positive electrode to form the battery. The charge-discharge chemical reactions are as follows:

Positive electrode: Ni (OH) 2 + OH- = NiOOH + H2O + e-

Negative electrode: M + H2O + e- = MHab + OH-

Total reaction: Ni (OH) 2 + M = NiOOH + MH

Note:

M: hydrogen alloy;
Hab: hydrogen adsorption; the process from left to right is the charging process; the process from right to left is the discharging process.

Features of NiMh batteries

Low-voltage nickel-metal hydride batteries have the following characteristics:

The voltage is 1.2 to 1.3V, which is equivalent to that of cadmium nickel batteries. The energy density is high, which is also more than 1.5 times that of cadmium nickel batteries.

They can be charged and discharged quickly, and they have good low-temperature performance. They are sealable and have strong resistance to overcharge and discharge. There is no dendrite formation, which prevents short circuiting. Overall, low-voltage NIMH batteries are safe and reliable.

High-voltage nickel-metal hydride batteries have the following characteristics:

The batteries have better over-discharge and overcharge protection, can withstand higher charge-discharge rate and also does not have dendrite formation. The mass specific capacity is 60Ah/kg, which is 5 times that of nickel-cadmium batteries.

They also have a long cycle life (up to a 1000 cycles) and excellent low-temperature performance. They are fully sealed and require less maintenance, and the capacity does not change significantly even at -10℃.

Preventing explosions from Ni-MH batteries

Below are just a couple of preventative measures to prevent NiMH batteries from exploding.

Avoid overcharging during use

Users should avoid overcharging because it is easy to cause the positive and negative electrodes in the battery to swell. This will cause the active material to fall off, the separator and the conductive network to be damaged, and the battery ohmic (Ω) polarization to become larger.

Storage of NiMH batteries

The nickel-metal hydride battery should be fully charged. If the battery is stored for a long period of time, the function of the hydrogen storage alloy of the battery negative electrode weakens, which affects the battery life.

Learn more about Himax NiMH batteries

Himax’s nickel-metal hydride batteries are the world ’s leading level, offers up to 2 times the C-rate of same size standard Nickel Cadmium Batteries. Due to their higher discharge rate and energy density features, users can use on more powerful equipments and applications.

Himax offers are variety of NiMH Battery Cells with wide temperature ranges. These Cells provide new electrode development which allows for a wide temperature range and long life. The cells have good availability with a wide cell selection that includes stable and compatible sizes.

June 16, 2020

Li-Polymer Battery, News

8 Advantages of Lithium Polymer Batteries

Lithium polymer battery is a kind of lithium-ion battery, but it has obvious advantages over liquid lithium battery (with high energy density, more compact, ultra-thin, lightweight, and high safety and size), is a novel battery. Below we detail the advantages of lithium polymer batteries.

1. Good safety performance

Lithium polymer batteries are structured in soft aluminum-plastic packaging, which is different from the metal case of liquid batteries. Once a safety hazard occurs, the liquid batteries are liable to explode, and the lithium polymer batteries can only be inflated.

2. Can be made thinner

Ordinary liquid lithium batteries adopt the method of customizing the casing first and then plugging the positive and negative electrodes. The thickness is less than 3.6mm. There is a technical limitation. The lithium-polymer battery does not have this problem. The thickness can be less than 1mm( ultra-thin battery can be 0.4mm in thickness), which meets the current mobile phone requirements.

3. Lightweight

Batteries with polymer weights do not require a metal case as protective packaging. Lithium polymer batteries are 40% lighter than steel-case lithium batteries of the same capacity and 20% lighter than aluminum-case batteries.

4. Large capacity

Polymer batteries have a capacity 10 ~ 15% higher than steel-case batteries of the same size and specifications, and 5 ~ 10% higher than aluminum-case batteries. They have become the first choice for color screen mobile phones and MMS mobile phones. The newest color screen and MMS mobile phones currently on the market also Polymer batteries.

5. Small internal resistance

The internal resistance of lithium polymer batteries is smaller than that of ordinary liquid batteries. At present, the internal resistance of domestic polymer batteries can even be less than 35mΩ, which greatly reduces the self-power consumption of the battery and extends the standby time of the mobile phone. It is completely possible. Reached the level of international standards. This kind of polymer lithium battery that supports large discharge current is an ideal choice for remote control model, and it has become the most promising product to replace the nickel-metal hydride battery.

6. The shape can be customized

Lithium polymer batteries can increase or decrease the cell thickness according to customer needs, develop new cell models, are cheap, have short mold opening cycles, and some can even be tailored to the shape of the cell phone to fully utilize the battery case space and enhance the battery capacity.

7.Good discharge characteristics

Lithium polymer batteries use colloidal electrolytes, which are subdivided into liquid electrolytes. Colloidal electrolytes have stable discharge characteristics and a higher discharge platform.

8.Simple protection plate design

Because of the use of polymer materials, the battery core does not ignite, does not explode, and the battery core itself has sufficient safety. Therefore, the protection circuit design of lithium polymer batteries can consider omitting PTC and fuses, thereby saving battery costs.

HIMAX specializes in custom, semi-custom, and off-the-shelf lithium polymer batteries. With over 15 years of customer service experience, HIMAX has developed a very complete service system, specifically tailored for our customers, which helps us in better understanding your needs in the first step of our communication, in a highly time-efficient way.

If you are interested in our lithium polymer batteries, please don’t hesitate to contact us at any time!

Email: sales@himaxelectronics.com

Himax Website: https://himaxelectronics.com/

June 9, 2020

Li-Polymer Battery, News, Ni-Mh Battery

Identifying Different Types of Medical Batteries

There are three types of medical batteries commonly seen in hospitals and clinical settings, and it is important to be able to distinguish them in order to know which custom battery adapter is the right fit when analyzing battery life:

Removable batteries: Nurses charge these packs on charging stations and get periodic analysis in the service center. Typical uses are defibrillators, infusion pumps, diabetic monitors, and surgical tools.

Built-in batteries: Increasingly, batteries are internal to the devices and are charged while the device is connected to the grid. Battery maintenance is done by the bio-med technician by opening the instrument. Typical uses are modern defibrillators, patient monitors, ventilators, surgical tools.

Standby batteries: These batteries are built into instruments on wheels and service as backup during transit and at bed-side. Many of these batteries are still lead acid. The depth of discharge is small if the nurse remembers to connect the AC cord. Typical uses are COW (Computer-on-wheels) blood transfusion units, as well as portable x-ray.

Dave Marlow, a certified biomedical equipment technician at the University of Michigan Health System, categorizes the battery as a “mixed bag of challenges”, with different medical facilities having different assortments of capabilities, battery technologies, manufacturing approaches, user training and experience differences. This is due to the fact that medical batteries must be designed, manufactured and labelled specifically for their use with specific medical devices (source) making the list of batteries designed for each machine essentially endless.

June 9, 2020

Li-Ion Battery, LifePO4 Battery, News

Why High Voltage Batteries?

Drones are being used more and more widely in all our lives, so the batteries that power these devices are increasingly advancing and being pushed to their limits. One of the biggest challenges to these batteries is endurance; more and more users need the power to last longer.

One such example is with an agricultural drone. Let’s say that the drone carries 10kg of pesticide with two ordinary Lithium Polymer (LiPo) batteries that have a capacity of 16000mAh in 6S (22.2V). This drone will only be able to last about ten minutes with these batteries, which farmers generally find to be too short. However, the use of high-voltage batteries with the same capacity and C rating can increase this flight time by 15-25%, which will increase the efficiency and operations.

We will explore why high-voltage batteries can improve flight duration and also look at the advantages of such batteries.

1. Weight

Without an increase in weight, high-voltage batteries provide better performance. This is key for UAVs since each drone has a specific payload that it cannot go over.

2. Higher Voltage

If we compare ordinary LiPo batteries to that of those with high voltage, we see a subtle change in voltage. Through this little voltage increase, users are able to get increased performance in their products.

Ordinary LiPo Batteries

The nominal voltage for a single LiPo cell is 3.7V. A 6S battery pack has a nominal voltage of 22.2V, and a 12S has 44.4V.

A single LiPo cell that is fully charged has 4.2V while a 6S has 25.2V and a 12S 50.4V.

High-Voltage LiPo Batteries

The nominal voltage of a single high-voltage LiPo cell is 3.8V, a 6S pack has 22.8V, and a 12S has 45.6V.

A single LiPo cell that is fully charged has 4.35V while a 6S has 26.1V and a 12S 52.2V.

3. Better Cycle Life

In the chart above, we can follow the discharge rate of several batteries. The high-voltage 4.4V batteries (shown in green) demonstrate a higher discharge rate and discharge capacity.

The above chart shows that, under the same discharge currents and cycles, the 4.4V (in blue) has a longer cycle life than the other batteries at 4.35V or 4.2V.

4. Increased Efficiency

Similar to the example offered at the beginning, we put two drones together for a simple test. Both drones carried 15kg of water with two batteries of 25C and 22000mAh in 6S.

The drone with the non-high-voltage batteries (22.2V) lasted 17 minutes and 50 seconds.

The drone with the high-voltage batteries (22.8V) lasted longer for 22 minutes and 10 seconds, lasting 4 minutes longer than the ordinary batteries.

Conclusion

According to the above data, the advantages of high-voltage UAV batteries are obvious.

We are able to custom, high-voltage cells and offer a one-stop service for your battery designs and solutions.

June 2, 2020

Li-Ion Battery, News

American University Develops A New Type Of Lithium-ion Battery That Will Not Catch Fire: Can Withstand Ballistic Impact

Lithium-ion batteries are required for smartphones, laptops, and electric cars. Although lithium-ion batteries have many advantages, they still have a fire hazard when they overheat. According to foreign media reports, The Johns Hopkins University is developing a new type of lithium-ion battery that will not catch fire and has made breakthroughs.

The researchers said that the new lithium-ion battery is very thin and flexible, unlike the current lithium-ion battery. Today’s lithium-ion batteries must be encapsulated in a rigid cylindrical or polygonal battery cover to isolate unstable and explosive components. The battery developed by Johns Hopkins University is very strong, can be immersed in water, cut, and even withstand ballistic impact.

ONE TOUGH POWER SOURCE

The popular myth that a spider is never more than a few feet away is arguably more true of lithium-ion batteries than of arachnids. Powering everything from smartphones and laptops to electronic cigarettes, lithium-ion batteries beat out alternative sources of power because of their top-notch energy density and long life cycle, meaning they can be recharged over and over again before breaking down. Yet for all these advantages, lithium-ion batteries come with a major concern: They can catastrophically ignite when they overheat.

At the Johns Hopkins Applied Physics Laboratory, a new type of lithium-ion battery that cannot catch fire is in the works. A team of researchers led by Konstantinos Gerasopoulos, a senior research scientist at the lab, recently made breakthroughs in their development efforts. The new battery is thin and flexible, unlike today’s lithium-ion batteries that must be packaged in rigid cylindrical or polygonal cases to wall off their volatile contents. The APL battery is also tough, able to withstand submersion in water, cutting, and even ballistic impacts.

“We wanted to create a battery that is as thin and powerful as the electronics it’s intended to power,” Gerasopoulos says. “And to do that, we needed to transform the battery’s safety.”

Swap out for safety

In batteries, a liquid electrolyte conveys electrons between two electrodes, providing an electric current that powers your device. Standard lithium-ion batteries contain an electrolyte with an organic solvent that, while efficient, happens to be flammable. Gerasopoulos and colleagues have developed a new class of electrolyte that uses lithium salts dissolved in water as an inflammable solvent. A polymer matrix—basically, a kind of plastic sponge—soaks up the water, and the ultimate result is a bendable, soft, contact lens–like electrolyte.

The positive with the negative

Usually, lithium-ion battery electrodes are foil-like and, when bent too much, can crinkle and be damaged. APL’s battery electrodes are instead crafted with Kapton, a flexible film often used to insulate a spacecraft from extreme temperatures. As an added bonus, Kapton is a readily available, off-the-shelf material, reducing the battery’s cost and complexity to manufacture.

More power for longer

The current iteration of the new electrolyte sustains 4.1 volts—not quite as much as conventional lithium-ion batteries, but it’s inching closer. The APL team also wants to improve the battery’s life cycle from around a hundred charges to more like a thousand, matching today’s typical battery performances. Continued tweaking of the polymer’s chemistry for better electrochemical stability should deliver on these two objectives.

The article is forwarded from Johns Hopkins Magazine by Adam Hadhazy

Original URL: HERE

June 2, 2020

Li-Ion Battery, LifePO4 Battery, News

How To Store 18650 Batteries Safely

What is the best way to store an 18650 battery?

In this blog post, rather than do my own testing – I will rely on the specification sheets provided by Panasonic, Samsung, and LG. We’ll look at the storing section of these spec sheets, and break down the important factors and what they mean. Scroll to the end, the overview, to get to the conclusions of the post quickly.

What does it mean?

There are three rows, each with different storage conditions. Note the second and third column are locked in place by the fourth. Each row represents recovering 80% of the battery’s usable capacity. Since the rated capacity of the NCR18650B is 3200 mAh, this 80% represents 2560 mAh after storage.

If you are storing an 18650 battery for less than a month, you may store it in an environment as hot as 50°Cand be able to recover 2560 mAh.
If you are storing an 18650 battery for less than 3 months, you may store it in an environment as hot as 40°Cand be able to recover 2560 mAh.
If you are storing an 18650 battery for less than 1 year, you may store it in an environment as hot as 20°Cand be able to recover 2560 mAh.

In the last case, storing for one year with a 20% drop in capacity translates to 1.6% loss of capacity per month, or 53 mAh.

In the first case (storing at high temperatures for less than one month) translates to a loss of 21 mAh per day.

Storage temperature and conditions

We can see from the above 3 items, it is temperature as the main factor determining the resulting capacity after storage, and ultimately how long you can store your battery for.

18650 batteries can be stored at very low temperatures, but high temperatures degrade them quickly. Rule of thumb: They must always be stored at less than 60°C.

Lithium-ion batteries, in most cases must maintain a voltage above 2.5V before they start to break down and decompose. Therefore, for long-term storage it is best to “top-up” your batteries when their voltage drops too low.

Note 1:When receiving new cells, the manufacture will ship them at a 40% charge. However, it is very likely this will soon be set at 30% as airline safety regulations demand safer transport, and less charge is safer.
Note 2:In these tests, Panasonic fully charged the batteries at 25°C, up to 4.2V. However, for long-term storage it is recommended not to store at a full charge, but to seek a lower voltage (more on that ahead).

Finally, the environment should be dry, or low humidity – without dust, or a corrosive gas atmosphere. Optimizing your cell’s environment becomes more important the longer they are kept stored. Anything above 3 months may start to be considered long-term.

Differences between the Samsung 25R and Panasonic 18650B

The Samsung 25R performs better during storage on all fronts. Across the board, the 25R can store at ten degrees lower than the 18650B. As well, the difference in higher temperatures, in favor of the 25R from 1 month, 3 months, to 1.5 years, is +10°C, +5°C, +5°C.

Most importantly, this 18650 battery can be stored a full six months longer and retain 90% capacity (10% more than the NCR18650B).

The optimal storing voltage

The 25R spec sheet notes that for long-term storage, the voltage should, rather than be fully charged, set at a lower, more optimal voltage. This is to prevent the degrading of performance characteristics. In the case of the 25R, the recommended voltage is 50 ± 5% of its standard (4.2V) charged state.

This works out to be a range between 3.64V and 3.71V

Other batteries have different ranges, but most are close to ~50% voltage which is usually around ~3.7V.

Overview

It is good to reference at least three batteries, and off the blog I have checked more. All 18650 batteries researched need a storage range of between -20 ~ +50°C (-4°F ~ + 122°F) or they will degrade, so this is a good rule of thumb to use.

Also keep in mind the maximum temperature for storage should never exceed +60°C (140°F). It is better to store in a cold environment, than a hot one.

Optimally, a good storage temperature should be closer to 25°C (77°F) or a somewhat lower. The closer you are to an optimal temperature, the longer you will be able to store your batteries without “topping up” and recharging them.

For the most part, the maximum time for 18650 storage before recharge is about one year.

If you are intending long term 18650 storage, a storage charge closer to 50% of usable capacity (~3.7V) rather than 100% (4.2V) will prevent faster battery degradation.

Frequently asked questions and notes

What happens if I don’t store my 18650 batteries correctly?

It will cause a loss of performance and your cells may leak and/or rust, and ultimately become unusable. Cells becoming unstable enough and exploding in storage is a possibility. In the worst case – explosion – it is not clear why this sometimes happens but it could be due to static, pressure, temperature, or packing incorrectly (allowing metal objects or batteries to touch).

Notes

For very short-term storage, don’t store the battery in a pocket or a bag together with metallic objects such as keys, necklaces, hairpins, coins, or screws when you are travelling.
Remove the battery from its application before storing it. For example, from your e-cigarette, flashlight, or electric bike. You should optimally store the batteries in a fire-proof container, with optimal environmental conditions.
Do not store 18650 batteries in or near objects that will produce a static electric charge.
Quick pressure changes can also cause 18650 batteries to malfunction

May 21, 2020

Li-Ion Battery, Li-Polymer Battery, News

Lithium Was Made In The First Three Minutes Of The Universe’s Existence

Lithium is thought to be one of the first elements made after the Big Bang. An enormous amount of Hydrogen, Helium, and Lithium (the first three elements on the periodic table) were synthesized within the first thee minutes of the universe’s existence.

This process is called Big Bang nucleosynthesis. Essentially, all elements heavier than lithium were made much later by stellar nucleosynthesis (like what is happening in the Sun).

Lithium is special for other reasons too

Lithium facts on history

Lithium is from Greek lithos meaning “stone”

Was used in the first man-made nuclear reaction in 1932

Lithium interesting facts

Soft enough to be cut by scissors

The lightest metal, and least dense solid element, so it can easily float on water

Does not occur freely in nature (it’s too unstable), but is found in nearly all lava, mineral water, and sea water

Pure lithium corrodes immediately when exposed to the moisture in air

Lithium in biology

All organisms have a little lithium in their bodies, but it does not seem to serve a biological purpose

Lithium in pills is used to treat bipolar disorder

Lithium in economics

80% of the world’s lithium is in salt flats between Argentina, Chile, and Bolivia

Let’s look at some pictures

Here are some pieces of raw lithium. Notice the lines and grooves cut into the soft metal by the tool they used to cut it. Also note what appears to be a bubble. It is most likely Hydrogen, as this is what is released when lithium reacts to water (or water from moisture in the air).

This is a photograph taken in Bolivia, in what is called ‘Salar de Uyuni’ – the biggest salt lake in the world. The amazing scenery holds a secret – a huge reserve of lithium. With the right investment, Bolivia may become what Kuwait was for oil to the new rechargeable revolution.

A fully developed lithium mine in the Atacama Desert. This is where the material in your 18650 battery most likely comes from.

This is a depiction of Asteroid 2012 DA14 which nearly missed Earth a few years ago. It was once famously valued at $195 billion US dollars for the large amount of metals like iron ore, copper, and lithium trapped inside. Maybe one day we won’t have to dig up our backyard to get the resources we need to enjoy ourselves.

So remember, next time you turn on your vaporizer, or other machine that uses li-ion batteries, to think a little about where it came from and what it means for our future.