Everything you should know about 21700 Chargers

Below you can find a list of the best chargers for 21700 cells. Please note that most 21700 chargers do not accept protected cells. The make of the cell doesn't really matter, as long as it's not built for a proprietary charging system like Olight. You can have Acebeam, Efest, Nitecore, Samsung, LG, Sony or any other brand of batteries and still use the following chargers. You just have to choose the one that meets your needs and accepts the length of your batteries. Note: Most of the chargers below will accept cells up to about 70mm (which is the length of a normal flat, unshielded 21700 battery).

Protected 21700 batteries are 73+ mm long. The 21700 batteries protected with a USB port are 75+ mm long. Please measure your batteries (and be careful not to short them) before ordering your charger.

Best Single Slot Magazines:

Fenix ARE D1:Small USB charger for lithium, NiCd and NiMh batteries!Accepts AA, AAA, NiMH, NiCd, Li-ion 4.2V (3.6V) cells and can easily handle 21700 batteries. Only 5V Micro USB input, no network, Includes a Powerbank function: 5V 2A. Charging Current 0.5A-2A, Reverse Polarity Protection, Price Range $15 – $25. In addition to charging Li-ion batteries such as 18500, 18350, 18650 and of course 21700, it can also charge AA and AAA rechargeable batteries. There is a small display which can show the battery type, charge current, time and Ah. Keep in mind that it basically loads at about 1.2A not 2A. On the 2A setting it drops to about 1.2A. It can charge LifePO4 batteries but does not automatically detect it. You need to set the charger to the LifePO4 setting.

Opus BT C100:Small charger with normal socket. The only programmable 21700 battery charger. Please note that it only fits unprotected 21700 batteries. Can recharge AA, AAA, NiMH, NiCd, LiFePO4 (3.2V), Li-ion 4.2V (3.6V) and Li-ion 4.35V (3.8V) cells

Display with details and settings to change, Charging current 0.5A-2A, USB output with 2.4A max. Accepts some longer and more protected 21700 batteries, but not all! Charging current can be set manually, including discharge function, analyzer, IR test (impedance) and update function. It can also charge 32650 batteries

Nitecore UMS2: Multi-chemistry charger with 2 slots for AA, AAA, NiMH, NiCd, Li-ion 4.2 V (3.6 V) and Li-ion 4.35 V (3.8 V) cells and can handle long 21700 protected batteries!!! Automatic charge current 0.2A-2A, Maximum charge current of 3,000mA, which needs to be set manually. LCD display with current, voltage etc. Capacity check and update function. This is the charger I personally use for all of my longer 21700 batteries. It doesn't matter if the battery is protected or if it has a USB port. They all fit in this charger. It uses the older micro USB protocol, but can still charge up to 3000mA for a single slot or 2*2000mA when using both slots.

21700 4-bay battery charger

MiBoxer C4-12: Special 4-bay charger with power bank function. It can handle batteries up to 73mm long with a 0.1A-3A charging current and has a 1A USB output (power bank function). Large LCD display to always keep the various charging stages under control. This charger is one of the fastest chargers on the market capable of charging 26650 batteries at 3A. Please note that some 21700 batteries protected or with a USB port may not fit.

Xtar X4 (extended version): Simple 4-bay 21700 charger for AA, AAA, Li-ion 4.2V (3.6V) cells. It can handle 2 large batteries such as D cells and 32650 batteries. Accepts 21700 protected batteries! (this is for the extended version only). Charging current 0.5A-2A (2x2A, 4x1A, 4×0.5A), Power Bank function for traveling and LCD display. The Xtar X4 uses a regular DC cable, so you don't have to worry about power like you do with some USB chargers. But you can still use a Micro USB cable for this charger when needed. In case you go abroad and don't have the correct wall plug with you. It also has a stable 1A USB output. Then you can charge your phone or tablet on the fly.

Vapcell S4+: Multi-chemistry charger: AA, AAA, NiMH, NiCd, LiFePO4 (3.2V), Li-ion 4.2V (3.6V) and Li-ion 4.35V (3.8V). It can handle 21700 batteries, but not the longest ones with USB ports. Charging current 0.2A-2A. It can handle most cylindrical batteries on the planet. It has a large display to view information on the status of the battery recharge. The Vapcell S4+ has received a lot of love from the flashlight community. The charger can handle AA, AAA, Li-ion and even charges up to a maximum of 3A.

SKYRC MC3000: The best charger for lithium batteries but only for short and unprotected 21700. Supported cell types : AA, AAA, NiMH, NiCd, LiFePO4 (3.2V), Li-ion 4.2V (3.6V) and Li-ion 4.35V (3.8V). Note: It cannot handle Protected 21700 batteries, nor button top 21700!

Ultimate control over every detail, 0.2A-3A charge current, Can handle literally every cylindrical battery on the planet. It has a large display, is Bluetooth compatible and has a PC connector. This charger does everything you can think of. You can load all kinds of chemicals. You can download, test, track, control and do anything with this charger. This is my favorite charger analyzer! You can set your own schedules, currents, etc. This is truly the most advanced charger in the world. If you want maximum control over your charging? Take this, and be done with it. You just need a manual to help you along the way. Note: Although it can accept 21700 batteries. This is for unprotected flat tops only. 21700 batteries with a button top or with a cap do not fit!

The best 8-bay 21700 battery charger

Xtar VC8 Plus: (There are 2 versions and only the PLUS version accepts 21700 batteries). This charger allows the recharging of AA, AAA, NiMH, NiCd, LiFePO4 (3.2V), Li-ion 4.2V (3.6V). It has 2 ports (DC input or USB-C), It can handle long batteries like 21700 with 0.25A-3A charge current (maximum 8 slots at 1 Amp or 4 slots at 2A). It has 2 large screens, built-in battery analyzer (capacity test). Xtar is a very popular charger in the charger market. In addition to cool chargers, they also make flashlights with a focus on divers. However, the VC8 Plus can handle 21700 batteries. They give you the option to order it with the DC plug or USB-C only. When ordering, make sure you get the Plus version and not the regular VC8 version. The Plus version is the one with longer spans. All 8 bays can be used simultaneously and the maximum charge current is 1A per battery when all 8 bays are used. Charging current increases to 2A when only 4 bays are used. The maximum charge current is 3000mA, when using 1 slot.

In recent years, flashlights powered by 21700 cells have increased exponentially. This type of battery is placed in terms of dimensions between the classic 18650 and the large 26650. But they manage to have very high capacities comparable to the 26650 and maintain extremely compact dimensions similar to the 18650. The torch manufacturers are making great use of them because the lights powered by 21700 cells can be pushed to the maximum to produce high light outputs and to guarantee high runtimes. But to charge these batteries there are often difficulties, given that the normal chargers used up to a few years may not adapt to this type of cell. In this article we have highlighted which are currently the quality chargers that allow you to charge this type of battery, listing their main specifications and technical characteristics.