Disposable battery sizing: 280 to 400 mAh

What mAh actually measures

A disposable vape battery mAh figure is charge, not energy and not runtime. A 350 mAh cell delivers 350 milliamps for one hour, or 700 milliamps for half an hour. To compare two cells you need energy, which is capacity multiplied by nominal voltage. Almost every cell in this class is a lithium polymer cell with a nominal voltage of 3.7 V, so a 350 mAh cell holds roughly 1.30 Wh. That figure has to cover every draw the device will ever produce.

Two devices with the same capacity can behave very differently. The board output, the coil resistance and how long a customer holds each draw all change how fast that stored energy drains. Capacity sets the ceiling. Everything else sets the rate.

How capacity turns into draws

The arithmetic is straightforward. A draw at 6 W held for three seconds consumes 18 joules, which is 0.005 Wh. Divide the cell energy by that and you get an ideal draw count. Then discount it, because no cell delivers its nameplate to the coil. The protection circuit, the discharge cut-off voltage, board losses and self-discharge during storage all take a share.

The table below assumes 70 percent of nameplate energy reaches the coil. That is a planning assumption for sizing a SKU, not a measured specification. Confirm the real figure by running units from your own batch to cut-off and counting the draws.

Cell capacity converted to energy and to draw count, at 3.7 V nominal

Cell capacity	Nominal energy	Draws at 6 W x 3 s, ideal	Draws at 6 W x 3 s, 70 percent usable	Draws at 8 W x 3 s, 70 percent usable
200 mAh	0.74 Wh	148	104	78
250 mAh	0.93 Wh	185	130	97
280 mAh	1.04 Wh	207	145	109
300 mAh	1.11 Wh	222	155	117
350 mAh	1.30 Wh	259	181	136
400 mAh	1.48 Wh	296	207	155

Read the last two columns as a range rather than a promise. The same cell loses about a quarter of its draw count when the board is set two watts higher.

Matching cell size to fill volume

There is no fixed conversion between millilitres and milliamp hours. Consumption per second depends on the coil, the wattage and the oil, so the only reliable route is measurement. Weigh a filled device on a balance that reads to a milligram. Run a counted number of timed draws. Weigh it again. The difference divided by the draw count gives milligrams consumed per draw. Divide the total fill mass by that figure and you have the number of draws the customer must get before the oil is gone.

Then compare that number with the working draw count in the table. If the device has to deliver more draws than the cell supports, you have three options and each costs something. Fit a larger cell, which adds weight, cost and charge time. Reduce the fill volume, which cuts the value the customer sees. Or make the device rechargeable, which adds a port and a charge controller. A 2 mL fill on a small non-rechargeable cell is the single most common source of complaints in this category, because the device dies with oil still visible in the window.

What supplier catalogues publish

Published ranges give a sense of where the market sits. CCELL lists all-in-one devices from 180 mAh on the Eco Star up to 500 mAh on the Palm Pro, with 280 mAh appearing most often across the Voca and Flexcell lines. Nextvapor publishes 280 to 380 mAh across its all-in-one range, with 280 mAh on the NEXGEN and 380 mAh on the LiteGo, Horizon and NovoPro. Both sets of figures are supplier claims taken from their own published material, not results we have tested, and Nextvapor's own site contradicts itself on several devices. Treat any figure you cannot trace to a signed specification as unconfirmed.

What else moves runtime

• Voltage setting. Power rises with the square of voltage, so a step from 2.8 V to 3.6 V into a 1.4 ohm coil raises the draw cost from about 5.6 W to about 9.3 W, roughly 65 percent more energy per draw. See variable voltage and variable wattage.
• Coil resistance. A fixed voltage board pushes more current through a lower resistance coil, so a 1.4 ohm build drains faster than a 1.7 ohm build at the same setting.
• Draw length. A customer who holds for five seconds instead of three cuts the draw count by about 40 percent. Your test protocol should use a length you can defend.
• Preheat. Each preheat cycle spends energy without producing a sale-relevant draw. Devices with a long preheat need headroom in the cell.
• Shelf time. Cells self-discharge. A device that sat in a warehouse for months arrives with less than it left with, which is why state of charge at shipment is worth specifying.
• Temperature. A cold cell sags under load and cuts off early. The energy is not lost, but the customer sees a flat device.

What to ask your supplier

Capacity is the easiest number for a supplier to state and one of the harder ones to verify, so ask for the surrounding detail rather than the headline alone.

• Nameplate capacity and measured capacity, with the discharge rate the measurement was taken at.
• The discharge cut-off voltage, which decides how much of the nameplate is actually reachable.
• Whether the device is rechargeable, and over which connector. A rechargeable disposable changes the sizing problem completely.
• The state of charge at shipment, and the puff cut-off timer duration.
• The cell manufacturer and datasheet, not just the pack specification.
• The UN 38.3 test summary, which you will need for transport in any case. See UN 38.3 shipping.

Empty Vapes stocks empty disposables and 510 batteries with low minimums from around 500 units, made to order in around six weeks, and CE, RoHS, REACH and EU Battery Regulation documentation on request. Registration duties in your market stay with you: see compliance.

FAQ

How many draws does a 350 mAh disposable give?

A 350 mAh cell at 3.7 V nominal holds about 1.30 Wh. A draw at 6 W held for three seconds costs 0.005 Wh, so the ideal count is about 259 and a working count is near 181 once you allow for 70 percent of nameplate reaching the coil. Treat that as a planning figure and confirm it by running units from your own batch to cut-off.

Is a higher mAh always better in a disposable?

No. A larger cell adds cost, weight and charge time, and the extra capacity is wasted if the oil runs out first. Size the cell to the fill volume and the wattage you intend to run. The trade-off is real in both directions: undersize it and the device dies with oil in it, oversize it and you ship lithium the customer never uses.

Does mAh tell me anything about vapour production?

No. Capacity is how much energy is stored, not how fast it is delivered. Vapour depends on the power reaching the coil, which is set by the board output and the coil resistance. Two devices rated at 350 mAh can produce very different draws.

What capacities do suppliers publish for empty disposables?

CCELL publishes a range from 180 mAh on the Eco Star to 500 mAh on the Palm Pro, with 280 mAh appearing most often. Nextvapor publishes 280 to 380 mAh across its all-in-one range. Both are supplier claims from their own material rather than figures we have tested, so ask for them in writing before you rely on them.

Sources

• Directive 2011/65/EU on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS) (recast), the official text on EUR-Lex.
• Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), the official text on EUR-Lex.
• Regulation (EU) 2023/1542 concerning batteries and waste batteries, the official text on EUR-Lex.

Trade guidance for B2B buyers, not legal advice. Empty hardware only, no cannabinoids and no e-liquid. B2B trade only, 18+ / 21+ per market. The buyer is responsible for the fill, for finished-product compliance and for product registration in their market.