Illustrative render of the Reliance RS50 cell✱ Render
Illustrative render generated from published specifications. Not a photograph of the actual cell.
21.35 × 70.3 mm · 67 g
21700NMC Mooch-tested · 70 A

Reliance RS50

Reliance · released 2024
Capacity4950 mAh17.82 Wh · 265.97 Wh/kg
Mooch continuous70 ASize to this figure
Resistance4DC internal resistance
Voltage window3.6 V2.5 – 4.2 V
Standard charge2500 mA~2 h to full

At 4950 mAh, this ranks #36 of 72 21700 cells in our database. Mid-range for capacity among 21700 cells. Higher discharge than 100% of 21700 cells in our database. Great for high-drain builds.

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Full specifications

Electrical
ChemistryNMC
Nominal voltage3.6 V
Max charge voltage4.2 V
Discharge cutoff2.5 V
Max continuous discharge70A (Mooch-tested)
Mooch CDR (trusted)70 A
Standard charge current2500 mA
Standard discharge current2500mA
Internal resistance4 mΩ
Physical
Form factor21700
Dimensions21.35mm × 70.3mm
Weight67 g
Top typeFlat Top
ProtectedNo
Wrap colorBlue
Performance
Capacity4950 mAh
Energy17.82 Wh
Specific energy265.97 Wh/kg
Energy density708.05 Wh/L
Power density (gravimetric)3,761 W/kg
Power density (volumetric)10,013 W/L
Year released2024
Operating Limits
Charge temp0°C to 60°C
Discharge temp-40°C to 80°C

Independent test data: Mooch's test of the RS50 ↗

At the standard 2500 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: Reliance RS50 (4950mAh)

C-RateCurrent (A)Theoretical runtime
0.2C0.99 A5h 00m
0.5C2.48 A2h 00m
1C4.95 A1h 00m
2C9.9 A30m
3C14.85 A20m
5C24.75 A12m
8C39.6 A7m 30s
10C49.5 A6m

Highlighted row is closest to the rated 70A continuous discharge.

Charging

RateCurrentEstimated time
0.5C2,475 mA~2h 00m
1C4,950 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
1P4,950 mAh17.8 Wh70 A
2P9,900 mAh35.6 Wh140 A
3P14,850 mAh53.5 Wh210 A
4P19,800 mAh71.3 Wh280 A
5P24,750 mAh89.1 Wh350 A
6P29,700 mAh106.9 Wh420 A

Example pack configurations

7S2P
24V ebike / small pack
14 cells25.2V nominal9,900mAh249Wh140A maxCell weight: 0.94 kg (add ~15% for wiring and BMS)
13S4P
48V ebike standard
52 cells46.8V nominal19,800mAh927Wh280A maxCell weight: 3.48 kg (add ~15% for wiring and BMS)
16S4P
DIY powerwall
64 cells57.6V nominal19,800mAh1140Wh280A maxCell weight: 4.29 kg (add ~15% for wiring and BMS)
4S6P
Power tool replacement
24 cells14.4V nominal29,700mAh428Wh420A 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

Dimensions21.35mm × 70.3mm
TopFlat Top
Format21700

Similar cells

Same format and chemistry, within ±500mAh capacity:

CellmAhCDRWhWeightWh/kg
Reliance RS50 (this cell)495070A17.8267g265.97
BAK 53E530010A19.169g277
Samsung INR21700-53G530010A19.172g265
LG M50T501414A18.170g258
Ampace JP50P1500040A1872g250
Amprius INR21700-50Q500050A1870g257

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.