What's in This Bundle
- 4x Panasonic NCR18650B, 3,400mAh, Flat Top
- 1x XTAR VC4SL 4-slot LCD USB-C charger
- 1x Type-C QC3.0 fast-charge cable, storage pouch, and manual (included with the charger)
A complete kit for anyone running a 4-cell device or building a small pack — four matched, genuine high-capacity cells paired with a charger that does more than just charge: it tests, monitors, and reports on each cell individually.
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 VC4SL 4 Bundle.
Why This Pairing Makes Sense
The NCR18650B is one of the highest-capacity mainstream 18650 cells available — it earned its reputation in laptop battery packs and early EV applications before becoming a favorite for high-capacity flashlights and DIY packs where runtime matters far more than burst current. Four cells bought together as a matched set means consistent capacity and internal resistance across the group, which matters for anything running cells in series or parallel. 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.
The XTAR VC4SL is a real step up from a basic charger: an LCD display showing live capacity, current, and internal resistance per slot, plus a capacity-test (grading) mode that charges, discharges, and recharges a cell to verify its actual capacity rather than just trusting the label. For a cell like the NCR18650B — where you'll see wildly different discharge ratings advertised across the market — having a charger that reports real, measured numbers is genuinely useful for cutting through that confusion.
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.
This listing is for Flat Top. For Button Top, click here
XTAR VC4SL — Charger Specs
| Parameter |
Value |
| Input |
Type-C, QC3.0 (9V⎓2A) |
| Charging Current (CC) |
3A×1 / 2A×2 / 1A×4 / 0.5A×4 / 0.25A×4 — steps down automatically as more slots are occupied, or can be manually adjusted within what the slot count allows |
| Charging Method |
3-stage charging (trickle → constant current → constant voltage), 4 independently monitored slots, dynamic power allocation based on input power available |
| Cut-off Voltage |
4.2V ±0.05V (Li-ion) / 1.45V ±0.1V (Ni-MH/Ni-Cd) |
| Cut-off Current |
≤120mA |
| Operating Temperature |
0°C to 40°C |
| Dimensions |
L156mm x W115mm x H35mm |
| Net Weight |
212g |
| Display |
Color LCD — press Mode to cycle between capacity, current, and internal resistance readouts per slot in real time |
| Special Modes |
Capacity/grading mode (charge → discharge → recharge cycle to verify true capacity), storage mode (charges or discharges cells to their rated storage voltage to extend battery life), standard charge mode |
| Compatible Cell Sizes |
3.6V/3.7V Li-ion: 10440, 14500, 14650, 16340, 17335, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650, flat-top 32650. 1.2V Ni-MH/Ni-Cd: AAA, AA, A, SC, C. Supports protected 20700/21700 cells; spring-loaded slots can also fit two 32650s and two 18650s at once |
| Safety |
Reverse polarity protection (displays "Err," shows 0V, and stops automatically), auto cut-off when fully charged, multiple charge protections |
A realistic note on charge time: the VC4SL's 1A-per-slot rate (with all four bays occupied and the QC3.0 adapter active) is a bit below the NCR18650B's own 1.625A standard charge current, so expect a full charge in roughly 4-4.5 hours for all four cells at once — slower than Panasonic's own reference rate, but well within a safe range.
Why the Capacity Test Mode Matters Here
The NCR18650B is a cell with genuinely inconsistent specs floating around online — you'll see it marketed anywhere from 4.875A to 6.8A depending on the seller. Buying four cells and being able to actually test their real capacity and internal resistance, rather than relying on whatever number happens to be printed on a listing, is a meaningful way to know what you actually bought. The VC4SL's grading mode runs each cell through a full charge-discharge-recharge cycle and reports the measured result.
Where This Bundle 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
-
4S, 2S2P, or similar DIY pack configurations where energy density matters more than discharge rate
-
Power banks and backup power builds built from a verified, matched set of four
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.
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 — that's exactly what the grading mode is for, if you want to check compatibility before combining batches.
-
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.
Frequently Asked Questions
Can this charger really tell me if a cell is underperforming? Yes — the grading/capacity test mode charges, discharges, and recharges a cell while measuring the actual capacity delivered, rather than relying on the printed rating. For a cell like the NCR18650B, where marketed specs vary a lot between sellers, that's a genuinely useful way to verify what you have.
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.
Do I need to charge all four cells at once? No — each of the four slots operates independently, so you can charge one, two, three, or four cells at a time, and mix different cell sizes or even NiMH batteries across the slots if needed.
What happens if I insert a cell backwards? The display shows "Err" for that slot and the voltage reading drops to 0 — the charger stops working on that slot automatically rather than attempting to charge.
In stock now. This bundle ships as a matched set of four genuine Panasonic NCR18650B Flat Top cells with a verified XTAR VC4SL charger — ready for high-capacity flashlights, power banks, and other moderate-drain builds out of the box.
