Illustrative render of the Tenpower 40TG cell✱ Render
Illustrative render generated from published specifications. Not a photograph of the actual cell.
21.1 × 70 mm · 67 g
21700NMC Mooch-tested · 35 A

Tenpower 40TG

Tenpower · released 2022
Capacity4000 mAh14.4 Wh · 214.93 Wh/kg
Mooch continuous35 ASize to this figure
Voltage window3.6 V2.5 – 4.2 V
Standard charge2000 mA~2 h to full

At 4000 mAh, this ranks #49 of 72 21700 cells in our database. On the lower end for capacity among 21700 cells. A mid-range 21700 cell. Solid for builds that don't need extreme capacity or discharge.

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Full specifications

Electrical
ChemistryNMC
Nominal voltage3.6 V
Max charge voltage4.2 V
Discharge cutoff2.5 V
Max continuous discharge35A (Mooch-tested)
Mooch CDR (trusted)35 A
Standard charge current2000 mA
Standard discharge current800mA
Physical
Form factor21700
Dimensions21.1mm × 70mm
Weight67 g
Top typeFlat Top
ProtectedNo
Wrap colorGreen
Performance
Capacity4000 mAh
Energy14.4 Wh
Specific energy214.93 Wh/kg
Energy density588.31 Wh/L
Power density (gravimetric)1,881 W/kg
Power density (volumetric)5,148 W/L
Year released2022
Operating Limits
Discharge temp-20°C to 80°C

Independent test data: Mooch's test of the 40TG ↗

At the standard 2000 mA charge rate, a full charge takes about 2 hours. The last bit is a slow taper to top it off.

Voltage operating window

Cutoff
2.5V
Nominal
3.6V
Max charge
4.2V

Usable range: 1.7V

C-rate conversion: Tenpower 40TG (4000mAh)

C-RateCurrent (A)Theoretical runtime
0.2C0.8 A5h 00m
0.5C2 A2h 00m
1C4 A1h 00m
2C8 A30m
3C12 A20m
5C20 A12m
8C32 A7m 30s

Highlighted row is closest to the rated 35A continuous discharge.

Charging

RateCurrentEstimated time
0.5C2,000 mA~2h 00m
1C4,000 mA~1h 00m

These are estimates for the constant-current phase. Real charge time is a bit longer because of the slow taper at the end.

Datasheet

Pack scaling

Series voltage configurations

ConfigNominal VMax VMin VCommon use
1S3.6V4.2V2.5VFlashlights, single-cell devices
2S7.2V8.4V5VRC vehicles, 7.2V packs
3S10.8V12.6V7.5VPower tools (10.8V nominal)
4S14.4V16.8V10VEbike (small), some power tools
7S25.2V29.4V17.5VEbike (24V system)
10S36V42V25VEbike (36V system)
13S46.8V54.6V32.5VEbike (48V standard)
14S50.4V58.8V35VEbike (52V high-power)
16S57.6V67.2V40VDIY powerwall

Parallel capacity scaling

ConfigCapacityEnergyMax discharge
1P4,000 mAh14.4 Wh35 A
2P8,000 mAh28.8 Wh70 A
3P12,000 mAh43.2 Wh105 A
4P16,000 mAh57.6 Wh140 A
5P20,000 mAh72 Wh175 A
6P24,000 mAh86.4 Wh210 A

Example pack configurations

7S2P
24V ebike / small pack
14 cells25.2V nominal8,000mAh202Wh70A maxCell weight: 0.94 kg (add ~15% for wiring and BMS)
13S4P
48V ebike standard
52 cells46.8V nominal16,000mAh749Wh140A maxCell weight: 3.48 kg (add ~15% for wiring and BMS)
16S4P
DIY powerwall
64 cells57.6V nominal16,000mAh922Wh140A maxCell weight: 4.29 kg (add ~15% for wiring and BMS)
4S6P
Power tool replacement
24 cells14.4V nominal24,000mAh346Wh210A maxCell weight: 1.61 kg (add ~15% for wiring and BMS)

Design a custom pack with this cell:

Application suitability

PowerwallsHigh capacity means more stored energy per cell. Fewer cells needed for a given kWh target.
Ebike PacksGood balance of capacity for range and discharge for hills. Works well in most ebike packs.
Car AudioEnough discharge to handle amplifier bursts without voltage sag.
High-Drain VapingAbove the 25A Mooch CDR threshold. Suitable for regulated and mechanical mods.
FlashlightsHigh capacity means long runtime. Great for everyday carry and extended use.
Power ToolsSufficient discharge and capacity for most power tool packs.

Physical dimensions

Dimensions21.1mm × 70mm
TopFlat Top
Format21700

Similar cells

Same format and chemistry, within ±500mAh capacity:

CellmAhCDRWhWeightWh/kg
Tenpower 40TG (this cell)400035A14.467g214.93
BAK 45D450030A16.269g235
Dmegc 45E450013A16.270g231
Epoch P45B450045A16.270g231
Molicel P45B450045A16.270g231
Samsung INR21700-45T450035A16.272g225

Frequently asked questions

Handling and safety

Lithium cells can be dangerous if mishandled. A few things to keep in mind:

  • Never charge above 4.2V or discharge below 2.5V.
  • Store cells at around 3.6-3.8V (roughly 40-60% charge) for long-term storage.
  • Don't mix cells with different capacities, chemistries, or states of charge in a pack.
  • Inspect wraps before use. A torn wrap can cause a short circuit.
  • Always use a BMS or balance charger appropriate for your pack configuration.
  • Keep cells away from metal objects, keys, and coins. A short across the terminals can cause fire.

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Specs come from manufacturer datasheets and independent testing; Mooch-tested discharge ratings are shown when available because they reflect real continuous performance better than headline datasheet numbers. Browse the full 18650 & 21700 cell database to compare every cell.

Disclaimer: We do our best to keep the information on this page accurate, but we cannot guarantee that all specifications are correct or up to date. Cell characteristics can vary between production batches and may change over time. Do not rely solely on this data for safety-critical applications. Always verify against the manufacturer's official datasheet before use.