Your question should be answered in the following steps
①li-ion means lithium battery. 18650 is the collective name for single-cell batteries for high-light flashlights. The voltage is 3.7 V.
② In the question you mentioned two 4800 mAh batteries. Whether you connect these two batteries in parallel or in series, it is not recommended to charge them with a cell phone charger.
a. If you have to use a mobile phone charger to charge, it is not impossible, but it will harm the battery life, and it will not be fully charged, or it will not be charged. .
b. Two batteries are connected in parallel, the voltage remains unchanged at 3.7V, and the capacity becomes larger. The fully charged voltage of the 18650 lithium battery is 4.2V. In terms of charger design, the maximum voltage is 4.2V, common chargers for lumin flashlightsThey all charge at 4.2V. The only difference is the charging current. is different, some big and some small. If you use a cell phone charger with a voltage of 5V, it can be charged if it is higher than 4.2V. You can decide for yourself whether this will affect the battery life.
c. If two batteries are connected in series, the voltage will be 3.7+3.7=7.4 V. The voltage of a cell phone charger is 5 V, which is lower than the base voltage of the battery and lower than the lowest voltage when the battery is completely discharged. If you want to use it to charge, it won't charge.
In summary, and what has been said above, the real capacity of your lithium battery is, in a sense, falsely stated. Personally, I suggest that in addition to individual flashlights, a charging circuit should be designed in the flashlight itself, which is suitable for chargingwith a voltage of 5 V. Generally speaking, I recommend using a common charger. strong light flashlights. This is not only safe, but also good for the battery. The lifespan will also be longer.
I hope my answer can help you, and I hope you will adopt it!
Why do 18650 lithium batteries have different capacities?
The 18650 battery model actually represents the size. 18 means the battery diameter is 18mm, 65 means the length is 65mm and the last 0 means the battery is cylindrical.
First of all, the sizes of the two are different. The 18650 is larger than the AA battery.
Second, the tensions of the two are different. The voltage of the AA battery is 1.2 V (rechargeable) or 1.5 V (disposable), while the voltage of the 18650 battery is 3.7 V
>Most important , their internal structures and their chemical reactionsare different. 18650 is a lithium battery, while AA batteries are mainly zinc-manganese batteries or alkaline batteries.
Detailed information:
Theoretical life of the 18650 battery is 1,000 times that of one charge cycle. Due to its high unit density and capacity, it is mainly used in laptop batteries. In addition, the 18650 is widely used in various electronic fields thanks toce to its good operating stability: high-end bright flashlights, portable power supplies, wireless data transmitters, electric heated clothing, shoes, portable instruments, portable lighting equipment, portable printers, industrial instrumentation, etc. Medical equipment, etc.
Baidu Encyclopedia-18650 lithium battery
18650 is one of the most commonly used lithium batteries. 18650 represents a diameter of. 18mm and a length of 65mm, cylindrical battery, widely used in electric vehicles, flashlights, uninterruptible power supplies and other occasions.
18650 Battery SpecificationsThe rated voltage of 18650 battery will be different depending on the battery type. Taking common lithium-ion batteries as an example, its nominal voltage is 3.7V, saturation voltage is 4.2V and conventional. Capacity is 2600mAh, but batteries from different manufacturers, or batteries from different models from the same manufacturer, will have different rated capacities. Common capacities include 2000 mAh, 2200 mAh, 2600 mAh, etc. Batteries of different capacities will have different manufacturing costs. Currently, the conventional capacity of 2000 mAh is considered low capacity. There are also less expensive batteries with capacities of 1500 mAh or even lower. 18650 cans. The highest capacity achieved is around 3400 mAh.
Why do 18650 batteries have different capacities?In fact, it's not just 18650 batteries. Other types of batteries, even if they are the same size, will have different capacities. This is related to the manufacturing process of the battery, the materials used, etc. There are differences in the manufacturing costs of batteries of different capacities, which will result in differences inns sale prices. When choosing a battery, you should make a choice based on factors such as actual capacity requirements and cost.
Although different capacities can be obtained by connecting batteries in parallel, when the space is relatively fixed, you should consider choosing batteries of different capacities. Some need to use larger capacities, and some only provide electrical power. but for parameters such as capacity, they are not demanding. In fact, besides the differences in rated voltage and capacity of 18650 lithium batteries, another important parameter is the discharge rate. This parameter determines the instantaneous and long-term output current of the battery, so 18650 batteries are generally divided into capacity type and power type. Capacity type batteries focus on capacity and are generally usefulized in situations where long-term low-current discharge is required; Power type batteries require instantaneous or continuous discharge current. Generally used in situations where the operating current is relatively large, such as power tools, etc.
The main reason that batteries of the same size will have different capacities is due to manufacturing cost. Considering this problem, it is necessary to make a reasonable choice according to the actual situation. As for the 5500mAh, 9800mAh, 12500mAh and other capacity batteries mentioned in the question, this is not realistic for a single 18650. These batteries are all batteries with virtual capacity standards. To achieve this capacity, you must use multiple batteries in parallel. reached.