Introduction to the selection method of 18650 lithium batteries and their chargers

18650 lithium-ion batteries are a common choice for high-power devices, and in terms of capacity, low self discharge rate, and large number of charging and discharging cycles, they also require long-lasting batteries.

18650 lithium-ion rechargeable batteries come in countless versions and have many functions, among which the most important are capacity, maximum pulse and continuous drain current, charging current, and protection of electronic devices.

The size of 18650 lithium-ion batteries is (diameter x length) 18.6 x 65.2 millimeters (0.73 x 2.56 inches), or circular 18 x 65 millimeters. The actual size may vary slightly depending on the manufacturer, but these small changes in size usually do not cause problems.

What are some considerations before purchasing a new 18650 lithium-ion battery?
1. The electrode end of the 18650 lithium-ion battery has a flat and button or side.
Most devices support the use of these two 18650 lithium-ion battery types, with capacity and maximum discharge current - these two values are closely related because high capacity design limits the maximum safe discharge rate, and vice versa, high discharge current design limits the capacity of lithium-ion batteries.
For example, the capacity of a high-capacity 18650 battery can reach or even exceed 5000 mAh, but the maximum safe continuous discharge rate of such batteries is usually within the range of 3-10 amperes.

On the other hand, 18650 lithium-ion batteries can safely and continuously provide 20-30 amperes of current for 1-5 seconds and up to 40-50 amperes of current, with a capacity typically in the range of 2500-3000 mAh.

Note: When promoting batteries, some manufacturers often overestimate the characteristics of their batteries. Therefore, reading comments and suggestions from other users is very important, not just the specifications and features provided by manufacturers. Alternatively, choosing a reputable brand may require paying extra.

Solder Lugs or Not - If there is a problem with the 18650 battery pack, please replace all batteries with new batteries (such as old batteries) that have the same capacity and charging/discharging current range (or better). Always use the same batteries produced by the same manufacturer, preferably from the same batch, and if it is necessary to solder their terminals, please have a professional soldering them for you, as this can be very tricky.

Due to the sensitivity of lithium-ion batteries to charging and discharging conditions, temperature, and other parameters, some 18650 lithium-ion battery models come with built-in protective electronic devices that can monitor battery parameters and protect the battery by turning it off when needed until conditions change.

Protective electronic devices require a certain amount of space, so the capacity of 18650 lithium-ion batteries will be slightly reduced, unless your device already has some kind of battery monitoring function.

18650 lithium battery charger
The modern 18650 lithium-ion battery charger is an intelligent battery charger that can sense battery type, chemical substances, status, etc. These battery chargers are typically used to charge various types of batteries, including NiCd, NiMH, and various lithium rechargeable batteries.

The most important functions of a smart battery charger include:
-Number of slots (number of rechargeable batteries),
-Charging current and mode, including battery testing, maintenance mode, complete discharge, trip current charging, etc;
-Acceptable battery size and chemical substances, etc
When selecting a battery charger according to your needs, please choose a battery charger based on both current and future needs.

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.