Ten amps is the number that governs this cell. It sets a ceiling near 29W on one and 58W on a pair, so it is a runtime cell for low-power use, not a battery for a mod run hard. For a VOOPOO Drag X3 Pod Mod Kit 80W at full power, see the Efest IMR 18650 3000mAh 20A Battery.
Mainstream 18650 cells from the companies that actually manufacture them top out around 3500mAh, and Efest’s own published 18650 range stops there too. 4000mAh sits above that ceiling. Efest are a rewrap brand, so the number is a label claim rather than a measured one, and no independent bench test of this cell exists. It is stated here as what Efest prints, which is all anyone can honestly say about it.
Mod Cells it takes Rated at Safe on this cell VOOPOO Drag X3 Pod Mod Kit 80W One 18650 or one 21700 80W About 29W, roughly a third of the mod’s rating VOOPOO Drag 5 Mod Kit 177W Dual 18650 Two 18650 177W About 58W, roughly a third of the mod’s rating VAPORESSO Armour Max Mod Kit 220W Dual Battery Two 21700, or two 18650 on the supplied sleeves 220W Not suitable, VAPORESSO specify 25A or better and this cell is 10A
- Fits
- VOOPOO Drag X3 Pod Mod Kit 80W, one cell, kept at or below about 29W
- VOOPOO Drag 5 Mod Kit 177W Dual 18650, two cells as a matched pair, kept at or below about 58W
- Any other 18650 device run gently, where runtime matters more than power
Does not fit ✕ VAPORESSO Armour Max Mod Kit 220W Dual Battery, it fails the 25A minimum VAPORESSO specify, by a wide margin ✕ Any sub-ohm coil run at the wattage it is marked for: that is where this cell is worked past its rating ✕ Any device needing a 21700, a smaller cell rattles in a larger bay and loses contact ✕ Any mechanical mod, where nothing limits the current the coil can draw |
Not sure it is the right one? Message us on WhatsApp with your mod and the wattage you actually run it at, and we will tell you whether this cell clears it. The two things that matter are the number of bays and the continuous discharge rating, and neither is printed anywhere on the mod.
A high-capacity cell with a modest current rating
This is a 4000mAh 18650 rated at ten amps continuous, and those two figures pull in opposite directions. Capacity is how much the cell holds; continuous discharge is how fast it can safely give it back. A cell built for the first tends to give up ground on the second, and this one does.
Ten amps is the figure that decides what it can power. Everything else on this page follows from it.
The arithmetic that turns amps into watts
The formula every mod owner should know: safe watts equals the cell’s continuous rating, multiplied by the number of cells, multiplied by three point two volts, multiplied by nought point nine for chip efficiency.
Three point two volts rather than three point seven, because a regulated mod draws more current as the battery empties and the worst case is a nearly flat cell.
Ten amps gives about twenty-nine watts from a single cell and about fifty-eight from a pair. Reversed, the same sum tells you what a mod demands: eighty watts from one cell needs around twenty-eight amps, a hundred and seventy-seven from two needs about thirty-one each, and two hundred and twenty from two needs thirty-eight each. This cell holds ten.
What that means in practice
It does not mean the cell is bad. It means it belongs in a device run gently rather than a device run hard, and the distinction is worth making plainly because the previous listing for this product recommended it for sub-ohm use.
A Drag X3 running a 0.6Ω pod coil at twenty-five watts is well inside this cell’s limits, and the extra capacity is a real benefit there, more vaping between charges than a 3000mAh cell gives. The same mod pushed to its full eighty watts asks nearly three times what this cell can hold. Same battery, same device, entirely different answer, and the only variable is where you set the wattage.
The Armour Max is a no, not a maybe
VAPORESSO specify cells of twenty-five amps or better for the Armour Max. Ten amps does not approach that, and the shortfall is not the kind that a cautious user can manage by turning the power down. A mod that can pull two hundred and twenty watts will pull it if asked.
If you own an Armour Max, the cell on this shelf that clears its requirement is the Vapcell P42A 21700 4200mAh 30A Battery, rated 30A. This one is not, and the shortfall is not the kind a cautious user can manage by turning the power down.
On the four thousand figure
Efest buys cells from the companies that manufacture them and applies their own wrap. That is normal in this trade and says nothing about quality on its own, but it does mean printed figures are listing claims rather than measurements.
Mainstream 18650s top out around three thousand five hundred milliamp-hours, and Efest’s own published 18650 range stops there. Four thousand is above the established ceiling for the format, and no independent bench test of this cell has been published. We state what Efest prints because it is what can be stated. Treat it as the label rather than as a measured figure, and buy the cell for its ten-amp rating, which is the number that governs safety either way.
Charging without shortening its life
Every mod that takes a removable cell also charges over USB-C, and for occasional use that is fine. If you swap a pair regularly, an external charger with independent bays and automatic termination does a better job, because it treats each cell separately and keeps a pair matched in a way in-mod charging cannot.
Charge at half an amp to one amp rather than the maximum the charger offers. Charge indoors, on a hard surface, and not unattended overnight. Never leave a lithium cell on a trickle charger.
Wraps, rings and the things that actually cause accidents
The metal case of this cell is electrically live and connected to the negative terminal. The plastic wrap and the white insulator ring around the positive end are the only things stopping it from touching the positive contact. A torn wrap or a nicked ring is not cosmetic.
If a wrap is damaged, stop using the cell. A proper heat-shrink sleeve and a fresh insulator ring restore it; tape does not, and a taped cell is a cell waiting to short.
Never carry a bare cell loose in a pocket or bag. A coin or a key across the terminals shorts it, and a shorted 18650 goes into thermal runaway with no warning. Carrying them in a plastic case prevents the most common real accident in this category.
Buying in pairs, and keeping them together
For a dual-battery mod, buy both cells at once, of the same brand and the same model. Charge them together, use them together, and never mix them with other cells.
Mismatched cells in series discharge unevenly, and the weaker one is driven hardest, which can push it below its safe cut-off. Mark them A and B on the wraps and always return them to the same slots.
Ordered early, this leaves Vapesoko Nairobi the same day for Nairobi and the towns around it, and reaches the rest of Kenya by courier in 1 to 2 business days.
A second high-capacity 18650 has arrived
Vapcell M35A 18650 3500mAh 10A Battery is the same ten-amp proposition with a better-evidenced capacity: 3500mAh sits at the established ceiling for the format and has been independently measured at that figure, whereas this cell’s 4000mAh is above the ceiling with no published test behind it.
Best for
- A pod mod run gently, where a charge lasting longer matters more than power
- Anyone whose Drag X3 lives at 25W on a 0.6Ω coil rather than at 80W
- Long runtime per charge from an 18650
- An honestly stated 10A rather than a number borrowed from a bigger cell
- Anyone who has been sold this as a sub-ohm battery and wants to know what it really does
Specifications
- Specification: Figure
- Category: Accessories
- Consumable type: Batteries
- Format: 18650
- Rated capacity: 4000mAh
- Continuous discharge: 10A
- Safe ceiling, one cell: About 29W
- Safe ceiling, two cells: About 58W
- Nominal voltage: 3.7V
- Charge to: 4.20V maximum
- Discharge to: 2.50V minimum
- Terminal: Flat top, unprotected
- Brand: Efest
- Format: 18650, flat top, unprotected
- Continuous discharge rating: 10A
- Rated capacity: 4000mAh as printed by Efest, above the established ceiling for the format and not independently verified
- Safe ceiling, one cell: Around 29W
- Safe ceiling, two cells: Around 58W
- Not suitable for: The VAPORESSO Armour Max, which requires 25A or better, and for sub-ohm coils run at their marked wattage
- Recommended charge current: 0.5A to 1A on an external charger
- Sold as: A single cell. Buy two at once for a dual-battery mod
- Who it is for: Adult smokers and vapers, 18+. Not suitable for non-smokers or for anyone who has never used nicotine.
- Delivery: Same day in Nairobi and nearby towns on an early dispatch; typically 1 to 2 business days elsewhere in Kenya
