21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
UltraFire_HIGH_DRAIN_LI-ION_RECHARGEABLE_BATTERY_12 - UltraFire
UltraFire_HIGH_DRAIN_LI-ION_RECHARGEABLE_BATTERY_12 - UltraFire
Continuous_Discharge_Current_9 - UltraFire
Continuous_Discharge_Current_9 - UltraFire
Internal_Safety_Features_5 - UltraFire
Internal_Safety_Features_5 - UltraFire
UltraFire 10440 500mAh 3.7V Batteries (2/10-Pack) - Protected - UltraFire
UltraFire 10440 500mAh 3.7V Batteries (2/10-Pack) - Protected - UltraFire
Mercury_Free_Lead_Free_Cadmium_Free_8 - UltraFire
Mercury_Free_Lead_Free_Cadmium_Free_8 - UltraFire
Safe_and_Reliable - UltraFire
Safe_and_Reliable - UltraFire
Low_Cost_and_Environmentally_Friendly_2 - UltraFire
Low_Cost_and_Environmentally_Friendly_2 - UltraFire
1-Year_Free_Warranty - UltraFire
1-Year_Free_Warranty - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire
21700 5000mAh 3.7V Rechargeable Batteries (2-Pack) - UltraFire

UltraFire® 21700 Rechargeable Battery

5000mAh | 3.7V | Protected

The UltraFire 21700 5000mAh rechargeable battery powers with high-drain output, built-in protection, and long-lasting, rechargeable reliability.

Size: 36.5mm x 16.7mm

SKU: 9484

$29.99
$37.99
SALE 21% OFF

Free Shipping 

Easy Returns

1-Year Warranty
Included

· New Generation Power

UltraFire
21700

Engineered for high-drain devices. 5000mAh of pure, protected energy. The ultimate power source for your professional gear.

EXPLORE SPECS

Technical
Excellence

Every UltraFire cell undergoes rigorous testing to ensure it meets our uncompromising standards for safety and performance.

10A

Max Discharge

500+

Cycles

Capacity

5000mAh

High Density Lithium

Voltage

3.7V

4.2V Peak Charge

Protection

PCB Built-in

Triple Safety Layer

Lifespan

500+ Cycles

Long-term Reliability

Advanced PCB Protection

Our integrated protection circuit board guards against overcharge, over-discharge, and short circuits, ensuring your devices and batteries stay safe under any conditions.

High-Drain Performance

Optimized for high-performance flashlights and electronic gear, the 21700 cell provides a steady 10A discharge rate without voltage sag.

Thermal Stability

Advanced chemical composition and structural design allow for excellent heat dissipation, maintaining peak performance even during extended high-power use.

The 21700 Advantage

Compared to traditional 18650 cells, the 21700 format offers significantly higher energy density and better power delivery.

Standard Cell

18650

Capacity

3400mAh

Power Output

Medium

UltraFire Premium

21700

Capacity

5000mAh

Power Output

High Performance

Power Your
Next Adventure

Don't settle for less. Get the original UltraFire 21700 5000mAh protected batteries today and experience the difference.

Specifications

Brand

UltraFire
Title

Battery Type

21700 Rechargeable Battery
Title

Material

Li-ion

Title

Capacity

5000mAh
Title

Voltage

3.7V

Title

Max Continuous Discharge

10A
Title

Energy

18.5 Wh
Title

Rechargeable

>1000 cycles
Title

Size

36.5mm x 16.7mm

Title

Weight

70g
Title

Chargeable

Yes

Title

Protective Case

Yes
Title

Certifications

CE, FCC, MSDS, UN38.8

Reviews

Customer Reviews

Based on 3 reviews
100%
(3)
0%
(0)
0%
(0)
0%
(0)
0%
(0)
G
Greg Saunders
I love how this flashlight feels in my hand

The Ultra Fire 201 7 Hundred battery flashlight is unlike any other flashlight I currently own (and I have about 30 of them). It feels great to hold in my hands.

Now, getting down to business: the battery life seems to last forever; I have yet to charge it! The brightness is impressive, although I typically use it on the diffused setting in positions 2 or 3. The focused light is outstanding, allowing me to narrow the beam and throw light all the way down the block.

It looks fantastic, operates well, and is well-designed with ergonomics in mind. It has quickly become one of my new favorite flashlights!

L
Luke
Great battery!

It holds a charge well, recharges quickly, and delivers strong, reliable power every time.

E
Edmund Kelley
Battery

Best flash light I ever had

Frequently asked questions

Q1: Is the 21700 battery safe to use?

Yes, our 21700 batteries come with a built-in protection board and are CE, FCC, MSDS, and UN38.3 certified for safe and reliable use.

Q2: How do I charge and maintain a 21700 battery?

Use a compatible charger designed for lithium-ion batteries. Avoid overcharging or exposing the battery to extreme heat, and store it in a cool, dry place when not in use.

Q3: How long does a 21700 battery last?

With proper use and charging, a 21700 battery can last for hundreds of charge cycles, providing long-lasting and reliable performance.

Use Cases

High-Capacity 21700 Cell

High-Drain Power Tool Battery Packs

Cordless Power Tool Battery Rebuilding

DIY E-Bike Battery Pack

PEVs (Personal Electric Vehicles)

Custom Electric Skateboard (esk8) Builds

Onewheel Battery Upgrades

High-Lumen Tactical Flashlights

Search and Rescue Torches

Long-Range FPV Drone Power

DIY Powerwall 21700 Modules

Off-Grid Solar Storage Banks

Vanlife Lithium Battery Conversion

High-Capacity Portable Power Stations

Emergency Prepper Power Banks

Custom Lithium-Ion Battery Packs

Ham Radio Portable Power Station

UltraFire® 21700 Rechargeable Battery

2 PCS
$29.99
$37.99