Vapcell U2 Battery Charger

Two bays, adjustable current, and a display that tells you exactly what is happening. The Vapcell U2 is a dual-bay universal charger built around an MCU management system and a military-quality sliding chute that accommodates cell sizes from 10440 all the way up to 26650.

Charging current is selectable: 0.5A, 1A, or 2A per bay on 3.7V Li-Ion / IMR / INR / ICR / NCR cells, with auto-detection for Li-Ion and Ni-MH. It also handles 3.2V LiFePO4 and 1.2V Ni-MH / Ni-Cd (including AA and AAA) with manual mode selection. 

Notably, it is one of the few chargers that handles 21700 protected batteries. Micro USB input. Real-time digital display. Safety protections cover over-charging, over-discharge, short circuit, and defective battery detection. Order with tracked delivery from Pirate Vapes.

Why vapers choose the U2:

• Handles 21700 protected batteries: One of very few chargers in this price range that fits and correctly charges 21700 cells with PCM protection circuits. Most budget dual-bay chargers do not.

• Adjustable charge current: 0.5A for sensitive or older batteries, 1A for standard daily charging, 2A when speed matters. Long-press the current button to switch.

• Defective battery detection: The U2 identifies and refuses to charge broken or faulty cells. If it cannot activate a battery, it tells you rather than forcing a charge cycle.

• Real-time digital display: Shows voltage, current, time elapsed, and capacity added for each bay simultaneously. Genuinely useful when checking a battery's state of charge rather than just watching a progress bar.

• Universal sizing: The sliding chute adjusts to accept cells from 10440 (tiny) through to 26650 (large vape and torch batteries) without adapters.

Vapcell U2 Battery Charger Features

Military-Quality Sliding Chute: What It Means

The U2's bay design uses a sliding chute rather than fixed contact plates. The positive contact slides outward to accept longer cells, then locks the battery into place under spring tension from the negative end.

Vapcell's descriptor of 'military quality' refers to the materials and tolerances on that sliding mechanism. The practical result is solid contact across a huge size range: from a 10440 cell (roughly the size of an AAA) through to a 26650 (the widest standard vape battery). No rattling, no poor contact, no adapters needed. Browse the full range of vape batteries at Pirate Vapes to pair with this charger.

The Digital Display Tells You What Is Actually Happening

Most budget chargers show a progress bar or LED dots. The U2 shows a digital tube readout for each bay: channel number, current battery voltage, charging current in use, time elapsed, and capacity added in mAh. It also displays the detected battery type (Li-Fe 3.20V, Li-ion 3.70V, or Li-ion 3.85V).

When a battery finishes charging, the display reads FULL. For vapers who use external-battery mods and want to track battery health over time, this level of information is meaningfully useful. It is also how you catch a battery that is no longer holding capacity properly.

Broken Battery Detection and 0V Activation

Two safety features worth understanding. First: broken battery detection. The U2 measures the cell before committing to a charge cycle. If it identifies a defective battery, it stops and does not charge it. This protects both the battery and the charger. Second: the 0V activation function. Batteries with PCM (protection circuit module) can sometimes drop to 0V if fully discharged.

Most chargers will read these as defective and refuse them. The U2 has an activation mode specifically for PCM-protected batteries at 0V, applying a trickle current to bring them back to a voltage the main charging circuit can work with. This is why the U2 handles 21700 protected batteries correctly when many other chargers do not.

Handles Three Battery Chemistries, Auto-Detected Where Possible

Insert a standard 3.7V Li-Ion or Ni-MH battery and the U2 identifies it automatically. For IMR / 3.85V Li-Ion and LiFePO4 / 3.2V cells, you short-press the mode button to manually select the correct chemistry before charging begins.

Most vapers will be using 18650, 20700, or 21700 Li-Ion cells and will not need to touch the mode button at all. The Ni-MH and AA/AAA compatibility is useful if you run other devices alongside your vape kit and want to consolidate chargers. Worth noting: the charger handles Ni-MH and Ni-Cd AA, AAA, SC, C, and D format batteries.

Adjustable Charging Current: 0.5A, 1A, or 2A

Long-press the current button on either bay to cycle through 0.5A, 1A, and 2A. For most 18650 and 21700 vape batteries, 1A is the standard safe charge rate. Use 2A if you need a fast charge and your battery's specs allow it. Older or smaller cells are better suited to 0.5A, which is gentler on the chemistry.

When two batteries are inserted simultaneously, the MCU caps the total at 2A and divides equally, regardless of what current you have manually set. Changing the current setting is possible at any point during a charge cycle.

Vapcell U2 Compatible Battery Sizes

The U2 accepts the following cylindrical cell formats. Sizes are given as diameter x length in millimetres.

Standard vape battery sizes (most commonly used):

• 18650: The most widely used vape battery format. Fits the majority of external-battery mods.

• 20700: Slightly larger than 18650. Common in high-drain devices.

• 21700: The current high-capacity standard. Larger still. Note: the U2 correctly handles 21700 protected cells.

• 18350: Compact format used in smaller regulated and mechanical mods.

• 20650 / 22650 / 26650: Larger format batteries used in high-drain mods and flashlights.

Full compatible size list:

10440 / 14430 / 14500 / 14650 / 16340 / 16650 / 17335 / 17500 / 17670 / 18350 / 18490 / 18500 / 18650 / 18700 / 20650 / 20700 / 21700 / 22650 / 26500 / 26650. Also: AA, AAA, SC, C, D format Ni-MH and Ni-Cd batteries.

How to Use the Vapcell U2 Battery Charger

Standard operation requires no setup for most vape batteries. The only reason to adjust settings is if you are using IMR, LiFePO4, or want a different charge rate.

1. Connect the U2 to a USB power source via the Micro USB cable. Use a 5V adapter capable of at least 2A output.

2. Slide the positive contact outward on the bay you are using, insert the battery, and release. The contact springs back against the positive terminal.

3. The display activates. It shows battery voltage and begins detecting the cell type. For standard Li-Ion and Ni-MH batteries, charging starts automatically within about five seconds with no input required.

4. For IMR (3.85V) or LiFePO4 (3.2V) batteries: short-press the mode button before charging begins to select the correct chemistry. The display shows the detected or selected battery type.

5. To change the charging current: long-press the current button and hold for three seconds until the display changes. Cycle through 0.5A, 1A, and 2A. You can adjust this at any point during a charge.

6. When a battery is fully charged, the display reads FULL. Remove the battery from the bay and disconnect the charger from the power source.

What's in the Vapcell U2 Box

One Vapcell U2 dual-bay battery charger. No Micro USB cable included. No batteries included. A standard Micro USB cable and a 5V / 2A (minimum) USB power adapter are required for use.

The Right Charger for Vape Batteries and More

The U2 covers the full spectrum of cylindrical rechargeable batteries used in vaping. Standard 18650 cells in dual-battery mods, 21700 batteries in high-capacity single-cell devices, and compact 18350 cells in smaller regulated mods are all within the U2's compatibility range.

It does not charge built-in batteries (USB-C or Micro USB charging handled by the device itself) or battery packs. It charges individual cylindrical cells only. Browse the full range of battery chargers and Vape Accessories at Pirate Vapes.

About Vapcell

Vapcell is a battery and charging equipment manufacturer that has built a strong reputation in the vaping and flashlight communities for producing high-capacity cells and competent chargers at a reasonable price. Their cell range covers 18650, 20700, and 21700 formats with independently tested capacity ratings.

The U2 is their entry-level dual-bay charger, positioned as a compact, feature-rich option rather than a bare-bones budget unit. The adjustable current output, digital display, and 21700 protected battery compatibility set it apart from cheaper alternatives at a similar price point.

Stock Up and Save

If you run a dual-battery mod, a charger that handles two bays simultaneously is the practical choice. Pick up the U2 alongside your next set of batteries from Pirate Vapes. Same-day dispatch before 4pm. Free Pirate Post on orders over £25. Tracked delivery throughout the UK.

Conclusion

Two independent bays, adjustable current at 0.5A, 1A, or 2A, a real-time digital display, compatibility across 20+ cell sizes and three battery chemistries, and proper handling of 21700 protected batteries. The Vapcell U2 is a capable dual-bay charger that gives considerably more information and flexibility than most chargers at this price.

If you use external-battery mods and want to keep track of what is happening to your cells during charging, it earns its price. Get it with your batteries at Pirate Vapes alongside the full range of Vape Batteries and chargers.

FAQs

Does the Vapcell U2 charge 21700 batteries?

Yes, including 21700 protected cells. The U2 includes a 0V activation function for PCM-protected batteries, which is specifically why it handles 21700 protected cells correctly when many cheaper dual-bay chargers refuse them.

How do I change the charging current?

Long-press the current button for three seconds. The display cycles through 0.5A, 1A, and 2A. You can change the setting at any point, including mid-charge.

Does the U2 charge two batteries at 2A each?

No. When both bays are occupied, the MCU caps total current at 2A and splits it between the two bays, so each receives 1A. With only one battery inserted, that bay gets the full 2A.

What battery types does the U2 automatically detect?

Standard 3.7V Li-Ion and 1.2V Ni-MH are auto-detected. IMR (3.85V) and LiFePO4 (3.2V) require manual mode selection via a short-press of the mode button.

Is a USB cable included?

No. The U2 uses Micro USB input, and you will need to supply a cable and a 5V / 2A (minimum) USB power adapter separately.

Will the U2 charge a completely flat battery?

If the battery has a PCM protection circuit and has dropped to 0V, the U2's activation function can attempt to recover it with a trickle current. Batteries without protection that drop to 0V are flagged as defective and will not be charged.