
We often buy flashlights. There are many types of flashlights. How to choose? We will not talk about the flashlight today, only the battery in the flashlight, because the battery determines the brightness index of the flashlight. Understanding power is essential!
When choosing an LED flashlight, it is wise to start by looking at the battery needed to operate the light. There are many types of batteries on the market, and each type has usage restrictions. Did you know that certain environments require certain batteries? This is only part of the consideration when choosing a lamp. BATTERY TYPES–BATTERY LIMITS–BATTERY SAFETY, you need to choose a part of the lamp.
There are many types of batteries today and they are powerful! There is a lot to know about all your battery choices-18650 rechargeable batteries, 14500 rechargeable batteries, 26650 rechargeable batteries, alkaline disposable batteries, etc. What does all this mean?
#1-First of All, We Must Understand the Battery Type

When choosing a flashlight, first you may want to consider what kind of flashlight you want to buy? Use disposable batteries, rechargeable nickel metal hydride, lithium ion, lithium batteries?
Factors such as the ambient temperature when using a flashlight should also be taken into consideration, because different batteries have different requirements for temperature. Not all batteries are designed for all temperatures.
Rechargeable batteries belong to one of the following chemical categories: nickel cadmium (NiCad), nickel hydride (NiMH), lithium ion (Li-Ion). Then there are non-rechargeable disposable batteries: alkaline batteries, carbon batteries and lithium batteries.
– Li-ion rechargeable battery
The rechargeable flashlight batteries found in lamps manufactured in the past few years are generally lithium-ion batteries. Lithium ion (Li-ion)
There are many sizes of batteries:
14500 rechargeable lithium-ion batteries: These batteries are smaller and similar in size to regular AA batteries. But generally it cannot be replaced.
16340 rechargeable lithium-ion batteries: The size of these batteries is close to CR123A/RCR123A batteries, but the length of 16340 batteries is usually a bit larger than that of CR123A batteries. The voltages between these batteries are usually different.
18650 rechargeable lithium-ion batteries: Compared with the size of standard AA batteries, these batteries are larger in diameter and length. The 18650 lithium-ion battery is a very popular battery source in today’s flashlights because the 18650 battery has such a large power. Currently, the size and style of 18650 batteries vary from manufacturer to manufacturer. However, the battery industry is working hard to standardize the size of 18650 batteries. 18650 batteries are typically 3.6/3.7 volts and have various mAh (milliampere) ratings. Generally speaking, the higher the mAh rating, the longer the running time between two charges.
26650 rechargeable battery: This is a high-performance/high-capacity battery designed to provide excellent power for high-power devices. The size of the 26650 battery is larger in diameter and longer in length. Because of their size, they can provide a lot of power for small flashlights.
– NiMH rechargeable battery
These rechargeable batteries usually come in AAA, AA, C, D, 9-volt and 12-volt sizes. They are an excellent all-round battery. The disadvantage is that their shelf life is shorter than that of lithium-ion batteries. To
– Lithium (non-lithium ion) non-rechargeable battery
They are available in AAA, AA, 9V and small cylinder (CR123A) sizes. Lithium batteries perform very well at temperatures below freezing. If you want to use a flashlight or headlamp in extremely cold temperatures, please make sure that the device is working with CR123A batteries.
– Alkaline non-rechargeable battery
These are the most common battery types and are not rechargeable. They are also very cheap. You will find that they have the following sizes: AAA, AA, C, D, 9 volts.
The disadvantages of alkaline batteries are that they are disposable, non-rechargeable, cannot be reused, and can hardly work at ultra-low temperatures.
But the advantages are simple, convenient, and low self-discharge rate, which is very suitable as a power source for emergency flashlights.
#2-Understand the Expectations of Different Battery Types

Once you have determined which battery type is right for you, you can actually choose a flashlight. If you need a bright flashlight, then you need a high-power battery! If you want a small flashlight, put it in your pocket or bag for emergency use, and require high brightness, then you also need to choose a high-power battery!
#3-Understand Battery Quality and Safety

Now that you have a better understanding of batteries, know that not all batteries are the same. The new lithium-ion battery is very powerful, but the price is high. If you want to save money, you must not buy a flashlight with this battery.
In addition to alkaline batteries, you always want to buy protected batteries. The protected battery has built-in safety measures to prevent overcharging, overdischarging and overheating.
When the battery is not in the device, it is very important to store the battery correctly. You always want to store the battery in a clean, dry place. It is important that the stored batteries are not connected in series, from positive to negative. Check your battery frequently for any bumps, torn packages, or deterioration. If you find any battery failure, please discard the battery properly immediately.