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Battery Knowledge

About Rechargeable Battery:

 There are five types of rechargeable batteries commercially available. Currently the most popular rechargeable batteries are Ni-Cd, Ni-MH and Li-Ion in consumer electronic industry,  Li-Ion battery are among our major products.

What is the cycle life of rechargeable battery?

 When a battery experiences a charge and discharge, we call a cycle or a period. In the stated charge and discharge principles and the capacity decline before a stated standard, the total cycles it can undergo called rechargeable battery cycle life.

What is rechargeable battery self discharge?

Primary battery or full charged secondary battery, when put aside for a period, it is capacity will decline or lose, this phenomenon calls self discharge that is electricity flee away. It is decided by the inner electro chemistry system, similar to water leakage from pond or reservoir.

What is battery inner impedance?

Battery impedance is the resistance when the current flow through an operating cell, in general the internal resistance is included both d.c. and a.c. resistance. For the rechargeable cell resistance is small and electrode is easy to be polarized along with producing a polarization resistance while measure d.c. resistance, the accurate value can't be measured.

What does the "Over-charge" affect the battery performance?

 "Over-charge" is described as a continuous charge action after the battery has been fully charged by a certain charge method. Since the capacity level from positive polarity is higher than the negative polarity, the positive polarity will generate Oxygen, which can be composed with the Cadmium generated from negative polarity via separator. In general condition, the internal pressure will not increase significantly, however, if the charging-current applied for battery is too much, the charging-time is extremely long and finally the Oxygen could not be used up in time, the battery will be defected by a pressure risen, battery distortion, leakage and so on. Definitely the battery's performance will decline as well  

What does the "Over-discharge" affect the battery performance?

If a cell's voltage reaches a designed value, that means the battery has discharge the stored capacity, but still the discharge action is continual, over-discharge will cause. Commonly the end voltage can be identified through discharge current, for example the end voltage is set at 1.0V/cell as discharged at 0.2C-2C, and 0.8V/cell at 3C or more, e.g. 5C or 10C. Over discharge may cause disaster, especially at heavy current or repeated over discharge. Commonly over discharge can make cell inner pressure raise, and the reversibility of activity materials both in positive and negative will be damaged. Even by charge only part can recover and the capacity is reduced obviously.

What does the short circuit affect the battery performance?

Any kinds of conductive material being bridged with the external terminals of a battery will result in short circuit. Based on the battery system, a short circuit may have serious consequences, e.g. rising electrolyte temperature or building up internal gas pressure. If the internal gas pressure value exceeds the limitation of cell cap endurance, the electrolyte will leak, which will damage battery greatly. If safe vent fails to respond, even explosion will occur. Therefore don't short circuit.

What is the performance of Lithium ion battery?

 High energy density;

High operation voltage;

    • No memory accumulation;
    • Long cycle life;
    • No pollution;
    • Light weight;
    • Very low self-discharge rate.

    What is the performance of Polymer Lithium ion battery?

    •  No liquid electrolyte, so never leak;
      • Can be made into various shape;
      • Can be made into thin battery, such as 3.6V, 400mAh, the thickness can decrease to 0.5mm;
      • High voltage in an battery: several battery with liquid electrolyte can be connected in series to get a high voltage only; the Li-polymer battery can get high voltage in an cell through multiplayer combination;
      • Same volume Li-polymer batteries` capacity is two times of Li-ion battery.

      What is the performance of Lithium MnO2 and Li-SOCL2 battery?

      •  High energy density;
        • Long shelf life;
        • Wide operating temperature;
        • Good sealing feature;
        • Steady discharge voltage

        Why do batteries packs with zero voltage or low voltage?

        (1) One of the cells voltages is 0V;

        (2) Plugs are short or open circuit, or ill touched;

        (3) Lead wires are broken from the soldering or weakly soldered;

        (4) Wrong battery connection or the connection tabs are miss or weak weld or broken off.

      • Safety Precautions:

        1. Read specification carefully or consult how to use correctly.
        2. According to electric appliance indication, please build in the battery positive pole and negative pole correctly.
        3. Do not put new and old battery or different kind and model battery into use together.
        4. Do not charge for the primary battery.
        5. Do not heat or disassemble the battery, even put it into fire or water.
        6. Do not short-circuit, in case of battery exploding, leakage or other casualty.
        7. If finding exceptional conditions, such as terrible odor, leakage, cracks and deformation on the battery crust, please stop using the battery immediately.
        8. Put the battery where children can not reach.
        9. If leaked liquid gets into eyes, flush eyes thoroughly with clean water at least 15 minutes, lifting upper and lower lids until no evidence of the chemical remains. Seek medical attention.
        10. If the electric appliance do not use for long-term, please take the battery out and store in a cool, well ventilated area.

      • Why does the lithium-ion battery pack have 0 voltage?

        Why does the lithium-ion battery pack have 0 voltage?
        For safety reasons, our lithium-ion battery packs have PCB protection to prevent overcharging and discharging of the battery pack. When the lithium ion battery is overcharged or discharged, the PCB will automatically cut off. Then you may find that the battery pack voltage is zero. This does not mean that the battery pack is exhausted. You can charge it with charger and everything will return to normal. Be sure to use the recommended charger. , this does not apply to batteries that have not been charged for more than two months. If not used, the battery should be recharged every 2 months to keep it fresh.

        For safety reasons, our lithium-ion battery packs have PCB protection to prevent overcharging and discharging of the battery pack. When the lithium ion battery is overcharged or discharged, the PCB will automatically cut off. Then you may find that the battery pack voltage is zero. This does not mean that the battery pack is exhausted. You can charge it with charger and everything will return to normal. Be sure to use the recommended charger. , this does not apply to batteries that have not been charged for more than two months. If not used, the battery should be recharged every 2 months to keep it fresh.

      • What is the best battery?

         Below is a summary of the strength and limitations of today's popular battery systems. Although energy density is paramount, other important attributes are service life, load characteristics, maintenance requirements, self-discharge costs and safety. Nickel-cadmium is the first rechargeable battery in small format and forms a standard against which other chemistry are commonly compared. The trend is towards lithium-based systems.

        Nickel-cadmium- mature but has moderate energy density. Nickel-cadmium is used where long life, high discharge rate and extended temperature range is important. Main applications are two-way radios, biomedical equipment and power tools. Nickel-cadmium contains toxic metals.

        Nickel-metal-hydride- has a higher energy density compared to nickel-cadmium at the expense of reduced cycle life. There are no toxic metals. Applications include mobile phones and laptop computers. NiMH is viewed as steppingstone to lithium-based systems.

        Lead-acid- most economical for larger power applications where weight is of little concern. Lead-acid is the preferred choice for hospital equipment, wheelchairs, emergency lighting and UPS systems. Lead acid is inexpensive and rugged. It serves a unique niche that would be hard to replace with other systems.

        Lithium-ion- fastest growing battery system; offers high-energy density and low weight. Protection circuit are needed to limit voltage and current for safety reasons. Applications include notebook computers and cell phones. High current versions are available for power tools and medical devices.

      • Characteristics of commonly used rechargeable batteries.

         1) Internal resistance of a battery pack varies with mAh rating, wiring and number of cells. Protection circuit of lithium-ion adds about 100mW.

        2) Based on 18650 cell size. Cell size and design determines internal resistance. Larger cells can have an impedance of <15mOhms,
        3) Cycle life is based on battery receiving regular maintenance. Failing to apply periodic full discharge cycles may reduce the cycle life by a factor of three.
        4) Cycle life is based on the depth of discharge. Shallow discharges provide more cycles than deep discharges.
        5) The self-discharge is highest immediately after charge, and then tapers off. The capacity loss of nickel-cadmium is 10% in the first 24h, then declines to about 10% every 30 days thereafter. High temperature increases self-discharge.
        6) Internal protection circuits typically consume 3% of the stored energy per month.
        7) The traditional nominal voltage is 1.25V; 1.2V is more commonly used to harmonize with lithium-ion (3 in series = 3.6V).
        8) Lithium-ion is often rated higher than the nominal 3.6V. Based on average voltage under load.
        9) Capable of high current pulses; needs time to recuperate.
        10) Applies to discharge only; charge temperature range is more confined. Delivers lower capacity at lower temperatures.
        11) Maintenance may be in the form of 'equalizing' or 'topping' charge to prevent sulphation.


        Wireless Headset Batteries

      • From Bluetooth to wireless headphones and headsets, JFC carries a vast selection of wireless headset batteries.your Bluetooth / headset does need a battery replacement after continuous use, and So before you go spend a hundreds of dollars on a new headset because your current one stopped working, come check us out first to see if a new batteries.

        Need help finding the correct battery? 

        Well we make it easy for you, simply type in the model of your battery in the search bar and you will get instant results! If you are too lazy to type (I know I am sometimes) we have a battery finder on the top of the page or just below you can use, just look for the brand and model/battery that if fits and you are good to go! Of course, we have no problem with you browsing Batteries In A Flash to find the correct Bluetooth battery replacement. Heck, give us a call if you have any questions, we are open 7 days a week

        What is Bluetooth?

      •  For those of you who are still new to Bluetooth, it is a Microchip technology enabling seamless voice and data connections between a wide range of Bluetooth devices through short-range, digital, two-way, radio transmissions operating in the 2.4 GHz ISM band. It normally can be linked to cars, phones, and other portable devices. It is often used today to prevent the use of hand-held cell phones while driving, bluetooth enables the user to drive with both hands while staying focused on the road.

      • Get 18650 Batteries From Laptop Batteries

        18650 batteries are a necessity for any do-it-yourself’er. If you going to build a project that needs batteries then more than likely your going to use 18650 batteries.  The problem is that they can be expensive if you’re buying them retail or even on the internet at an ecommerce store. 

        Assuming that you have a laptop battery that you are ready to tear into, lets talk about the precautions. You will first need to open the casing but you will need to be careful not to slice into the cells as this could cause a fire. When opening the casing use gloves and an utility knife to trace the seem. It may take several passes before the case is able to be opened.

        After the casing is open and the cells are exposed, the wires and ribbon cable attached to the circuitry need to be cut with wire cutters. The cells inside the casing maybe glued or taped securely into the casing. You will need to use a flat blade screwdriver to pry them loose. Be careful not to crush the cells during this process.

      •  Battery C Rating Explained and Demystified

      • Batteries are a bit of a mystery to people. They are not quite an electronic, so you dont have to program the time on them. However, they all have strange markings on them that battery manufactures expect you to understand. For instance, C Rating is found on most Li-PO battery packs. Typically it will look will something like 20C or 20C – 30C. So what does it mean? Watch the video below or read on for the explanation.
      • C Rating Background

        C Rate is derived from Coulomb’s Law developed by French physicist Charles Augustin de Coulomb. The c-rate is the governing measurement of what current a battery is charged or discharged at. For example, the posted mAh of the battery is the 1C rating. If a battery is labeled 2000mAh, then its 1C rating is 2000mAh.

        To make this simple, the battery should provide 1C current for one hour. In our example above that would be 2000mAh or 2A of current for one hour. The same applies for a 0.5C rating. Again using the 2000mAh battery, it would deliver 1000mAh or 1A of current for two hours.

      • Battery C Rating Examples

        The formulas for the example are simple. If for any reason I have not made it clear, comment for further explanation. The following examples are based on the first line in the table. 1600mAh battery with a 10C rating.

        Continuous Discharge
        (mAh / 1000) x C Rate = Continuous Discharge Amperage
        (1600 / 1000) x 10 = 16A

        Run Time for Safe Continuous Discharge
        60mins / C-Rate = Run Time
        60mins / 10C = Discharge 16A for 6mins

        Use the formulas above, the table has examples of common amperage batteries and C Rates found on them. They are not for literal products and are only used as hypothetical examples.

        Amperage (mAh)
        Cont. Discharge (A)
        Run Time (Mins)
        20C – 40C
        40A – 80A
         3 / 1.5

        As you you can see in the chart, the 3500mAh battery will produce a higher continuous discharge than the 5000mAh battery. However, the 5000mAh battery will deliver its current 33% longer than the 3500mah battery. So which result is more important to your application. Longer run time or higher continuous amperage discharge. If your battery is in an airsoft gun your probably looking for run time. If your using an e-cigarette battery then your probably looking for a higher continuos amperage.