What's in This Bundle
- 6x LG INR18650-MJ1, 3,500mAh, Flat Top
- 1x XTAR VC4SL 4-slot LCD USB-C charger
- 1x XTAR MC1 single-slot USB-C charger
- Cables, manuals, and storage pouch included with both chargers
This bundle exists because there's no clean single charger that handles exactly 6 cells at once. Rather than force you into a mismatched combo, we've paired the 4-slot VC4SL with the compact single-slot MC1 — together they give you 5 charging slots, so 5 of your 6 cells can charge at the same time, with the last one following right behind.
Flat Top is the MJ1's native factory configuration — this is the standard, unprotected form LG Chem manufactures the cell in.
This listing is for Flat Top. Looking for Button Top? Click here to buy: LG INR18650-MJ1 Button Top + XTAR MC4S 4 + XTAR MC1 Bundle.
Why This Pairing Makes Sense
The MJ1 was, at release, one of the highest-capacity 18650 cells on the market — LG's NMC811 chemistry with a silicon-graphite anode pushes energy density further than most cells in this size while still holding a genuine 10A continuous discharge rating. Six cells bought together as a matched set means consistent capacity and internal resistance across the whole group — which matters more than usual here, since independent testing has shown some batch-to-batch capacity variability with this cell. Flat Top is the standard terminal type for most current devices — DIY packs, work lights, and equipment that doesn't rely on spring-loaded contacts.
The VC4SL handles the bulk of the charging with its LCD display and capacity-test (grading) mode — a genuinely useful check for this cell given that documented batch variability. The MC1 rounds things out as a small, genuinely portable single-slot charger — useful on its own for topping off a spare cell, throwing in a bag, or keeping in the car, not just as filler to hit a slot count.
LG INR18650-MJ1 — Battery Specs
| Parameter |
Value |
| Brand & Model |
LG Chem INR18650-MJ1 |
| Chemistry |
NMC811 cathode, graphite-silicon anode |
| Capacity |
3,500mAh nominal (3,350mAh minimum) |
| Nominal Voltage |
3.635V average |
| Standard Charge |
0.5C (1.675A) CC, 4.2V CV, 50mA cutoff |
| Max Charge Voltage |
4.2V ±0.05V |
| Max Charge Current |
1.0C (~3.35A) |
| Standard Discharge |
0.2C (670mA), 2.5V cutoff |
| Max Continuous Discharge |
10A |
| Cycle Life |
400 cycles (charge 1.5A / discharge 4A) to 80% capacity |
| Charge Temperature |
0°C to 45°C |
| Terminal Type |
Flat Top (native factory configuration) |
| Protection Circuit |
None (unprotected cell) |
| Weight |
~49g max |
| Cell Dimensions |
Diameter 18.4mm (max 18.5mm), Height 65.0mm (max 65.2mm) |
A note on real-world capacity: independent lab testing has shown this cell's actual measured capacity can run somewhat below its 3,500mAh nominal rating in some batches — one third-party comparison test measured roughly 3,205-3,384mAh depending on discharge rate, noticeably below the datasheet figure. This isn't unique to the MJ1, but it's a genuine reason to prioritize matched-batch, verified sets like this bundle over mixing cells from different orders.
This listing is for Flat Top. For Button Top click here
XTAR VC4SL — Charger Specs (4 Slots)
| Parameter |
Value |
| Input |
Type-C, QC3.0 (9V⎓2A) |
| Charging Current (CC) |
3A×1 / 2A×2 / 1A×4 / 0.5A×4 / 0.25A×4 |
| Charging Method |
3-stage charging (trickle → constant current → constant voltage), 4 independently monitored slots |
| 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 — capacity, current, and internal resistance readouts per slot |
| Special Modes |
Capacity/grading mode, storage mode, standard charge mode |
| Compatible Cell Sizes |
10440 through 26650, flat-top 32650, plus 1.2V Ni-MH/Ni-Cd (AAA/AA/A/SC/C); supports protected 20700/21700 |
| Safety |
Reverse polarity protection ("Err" display, 0V shown), auto cut-off, multiple charge protections |
XTAR MC1 — Charger Specs (1 Slot)
| Parameter |
Value |
| Input |
Type-C, 5V⎓1A |
| Charging Current |
1A (single slot, constant current) |
| Charge Cut-off Voltage |
4.2V ±0.05V |
| Charge Cut-off Current |
<130mA |
| Operating Temperature |
0°C to 40°C |
| Dimensions |
L103mm x W25mm x H30mm |
| Net Weight |
27g |
| Charging Method |
3-stage charging (trickle → constant current → constant voltage), automatic Li-ion detection |
| 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; supports protected 21700 |
| Extra Feature |
"0V" activation technology — attempts recovery on over-discharged cells |
| Status Indicator |
Green = standby/fully charged, Red = charging, Off = reverse polarity or abnormal insertion |
| Safety |
Intelligent detection, auto cut-off, overcurrent/overcharge/overvoltage/short-circuit/reverse-polarity protection, soft-start |
| Package Includes |
MC1 charger, USB-C cable, user manual |
A realistic note on charging all 6: the MJ1's own standard charge current is 1.675A, meaningfully above the 1A per slot both the VC4SL and MC1 deliver — a conservative, safe rate across all 5 active slots. Expect a full charge in roughly 4.5-5 hours for those 5 cells, with the 6th following once a slot opens up.
Why the Capacity Test Mode Matters for a 6-Pack
This is one of the clearest cases in our lineup for why grading mode earns its keep. Independent testing has already shown this cell can land meaningfully under its nominal rating depending on batch — buying six cells and being able to verify their actual measured capacity, rather than just trusting the 3,500mAh figure, tells you what you actually have before you build a pack around it. Run them through the VC4SL in two batches of four (with the MC1 handling overflow) and flag any cell with a wider gap during testing rather than mixing it into a tight pack build.
Where the MJ1 Actually Fits
-
High-capacity flashlights and headlamps running moderate-to-high output modes
-
E-bike and e-scooter packs where 10A per cell in parallel is sufficient
-
6S, 2S3P, 3S2P, or similar DIY pack configurations prioritizing energy density with more current headroom than pure energy cells
-
DIY power banks and backup builds wanting more runtime per cell than lower-capacity options, built from a verified matched set
Not the right choice for sub-ohm mechanical mods, or anything regularly demanding more than 10A per cell — for those, a dedicated high-drain cell like the Samsung 25R or 30Q is a better match.
Things Worth Knowing Before You Use This Kit
-
This is an unprotected cell. Both chargers enforce their 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 MJ1. Given the batch-to-batch capacity variability noted in independent testing, running the grading test before combining batches is genuinely worthwhile.
-
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.
-
10A is a real ceiling. Don't use these in devices that regularly demand more current than that.
-
The MC1 charges one cell at 1A — it's not meant to replace the VC4SL for bulk charging, just to round out the slot count and serve as a lightweight backup charger.
Frequently Asked Questions
Can all 6 cells charge at the same time? 5 of the 6 can charge simultaneously — 4 on the VC4SL, 1 on the MC1. The 6th cell follows once a slot frees up.
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. Given the batch variability documented for this cell, that's a genuinely useful check.
Why might my actual measured capacity come in under 3,500mAh? Independent testing has shown some batch-to-batch variation with this cell, with measured capacity sometimes landing in the 3,200-3,400mAh range depending on discharge rate and batch. It's still a genuine high-capacity cell — just worth knowing that the nominal figure is a typical rating, not a guarantee for every individual unit.
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 LG manufactures this cell natively. If your device specifically calls for Button Top (a raised positive terminal), you'll want that version instead.
Is this kit protected-cell compatible? Both chargers support protected 21700 cells (the VC4SL also supports protected 20700) if you use them for those later. The LG MJ1 cells included in this bundle are unprotected bare cells, standard for this model.
In stock now. This bundle ships as a matched set of six genuine LG INR18650-MJ1 Flat Top cells with a verified XTAR VC4SL and XTAR MC1 charger combo — ready for high-capacity flashlights, e-bikes, and general electronics out of the box.
