What's in This Bundle
- 2x Panasonic NCR18650B, 3,400mAh, Flat Top
- 1x XTAR MC2 dual-slot USB-C charger
- 1x USB-C charging cable (included with the charger)
A ready-to-go starter kit for anyone who needs two matched, genuine high-capacity 18650 cells and a compact way to charge them — no separate charger purchase, no guessing whether a charger you already own is a safe, appropriate match.
Flat Top is the NCR18650B's native factory configuration — this is the standard terminal style Panasonic manufactures the cell in, not a converted or adapted version.
This listing is for Flat Top. Looking for Button Top? Click here to buy: Panasonic NCR18650B Button Top + XTAR MC2 Bundle.
Why This Pairing Makes Sense
The NCR18650B is one of the highest-capacity mainstream 18650 cells available, and it earned its reputation in laptop battery packs and early EV applications (Tesla's original Model S packs used this cell) before becoming a favorite for flashlights, laptop-style DIY packs, and other builds where capacity matters far more than burst current. Flat Top is the standard terminal type for most current devices — DIY packs, general electronics, and equipment that doesn't rely on spring-loaded contacts. Buying two cells together as a matched pair means you're starting with cells from a similar batch, which matters for anything that runs cells in series or expects consistent performance between them.
The XTAR MC2 pairs well here because it charges both slots at a full 1A simultaneously, with no current-splitting trade-off for using both bays at once. It's a genuinely portable charger that doesn't ask you to sacrifice charge speed for its small size.
Panasonic NCR18650B — Battery Specs
| Parameter |
Value |
| Brand & Model |
Panasonic NCR18650B |
| Capacity |
3,400mAh typical (3,200mAh minimum rated) |
| Nominal Voltage |
3.6V |
| Max Charge Voltage |
4.2V |
| Standard Charge Current |
1.625A |
| Discharge Cutoff Voltage |
2.5V |
| Max Continuous Discharge |
4.875A per Panasonic's own spec sheet |
| Discharge Temperature |
-20°C to 60°C |
| Terminal Type |
Flat Top (native factory configuration) |
| Protection Circuit |
None (unprotected cell) |
| Weight |
~45-47g |
| Cell Dimensions |
~18.3mm x 65mm |
A note on discharge current claims: you'll see this cell advertised elsewhere at 6.7A or 6.8A continuous. That figure doesn't match Panasonic's own published spec sheet, which lists 4.875A as the maximum continuous discharge rating. This is a genuine high-capacity, moderate-drain cell — not a high-drain one — and it's worth knowing that going in, especially if you're comparing it to cells like the Samsung 30Q or 25R.
This listing is for Flat Top. For Button Top, click here
XTAR MC2 — Charger Specs
| Parameter |
Value |
| Input |
Type-C, 5V⎓2A |
| Charging Current |
1A per slot — both slots simultaneously, no splitting |
| Charging Method |
3-stage charging (trickle → constant current → constant voltage), 2 independent slots with automatic detection |
| End-of-Charge Voltage |
4.2V ±0.05V |
| End-of-Charge Current |
<130mA cutoff |
| Operating Temperature |
0°C to 40°C |
| Dimensions |
L103mm x W53mm x H30mm |
| Weight |
54g |
| Compatible Cell Sizes |
10440, 14500, 14650, 16340, 17335, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650 (3.6V/3.7V Li-ion), including protected 21700 cells |
| Extra Feature |
"0V" activation technology — can recover some over-discharged cells |
| Status Indicators |
Green = standby/fully charged, Red = charging, Off/unlit = reverse polarity or abnormal insertion |
| Safety |
Reverse polarity protection, short-circuit protection, 3-stage charge control |
A realistic note on charge time: the MC2's 1A per slot is actually a bit below the NCR18650B's own standard charge current of 1.625A, so expect a full charge in roughly 4-4.5 hours rather than Panasonic's faster reference time — slower, but well within a safe range, and the trade-off for a charger this compact.
Where the NCR18650B Actually Fits
-
High-capacity flashlights run at low-to-moderate output — long runtime is the whole point of this cell
-
Laptop-style and general electronics packs — its original and most common use case
-
Power banks and backup power builds where energy density matters more than discharge rate
-
Low-drain DIY electronics that won't come close to demanding more than 4.875A per cell
Not the right choice for sub-ohm high-output flashlights on turbo, or power tools — this cell's discharge ceiling is meaningfully lower than dedicated high-drain cells like the 30Q, 25R, or 20R. If that's your use case, look at one of those instead.
Things Worth Knowing Before You Use This Kit
-
This is an unprotected cell. The charger enforces its own voltage and current cutoffs, but your device still needs to handle discharge-side protection.
-
Don't mix these cells with older ones you already own, even if they're also NCR18650B. Pairing cells from different ages or usage histories in a series/parallel setup can cause imbalanced charging over time.
-
Flat Top won't work in devices that specifically require Button Top cells — check your device's battery compartment before ordering if you're not sure which terminal type it needs.
-
Don't put these in a high-drain device. A 4.875A ceiling is a real limit — pushing this cell toward the 6-7A figures sometimes advertised elsewhere risks excess heat and accelerated wear, not just reduced performance.
Frequently Asked Questions
Can this charger handle the NCR18650B's full capacity safely? Yes. The MC2's 1A per slot is a safe rate for this cell, even though it's a bit under Panasonic's own 1.625A standard charge current — expect roughly 4-4.5 hours for a full charge, both cells at once.
Why do different sellers list different max discharge ratings for this cell? Panasonic's own datasheet lists 4.875A as the maximum continuous discharge current. Some listings advertise 6.7A or 6.8A, which doesn't match that primary source — treat the higher figures with caution rather than as confirmed specs.
Will Flat Top cells work in my device? If your device uses spring-loaded, flat, or magnetic-style contacts without a raised positive terminal requirement, Flat Top is the correct choice — and it's how Panasonic manufactures this cell natively. If your device specifically calls for Button Top (a raised positive terminal), you'll want that version instead.
Can I charge two different battery sizes at once? Yes — the MC2's two slots operate independently with automatic size and chemistry detection, so you could charge one 18650 and a differently-sized cell (like a 21700) at the same time if needed.
Is this kit protected-cell compatible? The MC2 supports protected 21700 cells if you use it for those later. The Panasonic NCR18650B cells included in this bundle are unprotected bare cells.
What does the "0V activation" feature do? It lets the charger attempt a slow, controlled charge on cells drained deep enough that a standard charger would refuse to recognize them at all. It won't save every over-discharged cell, but it can recover some that would otherwise be written off.
In stock now. This bundle ships as a matched pair of genuine Panasonic NCR18650B Flat Top cells with a verified XTAR MC2 charger — ready for high-capacity flashlights, power banks, and other moderate-drain builds out of the box.
Authentic Panasonic Cells – sourced from official distributors. No rewraps, no fakes.
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