Ampace JP40 21700 4000mAh 70A

Ampace JP40 21700 4000mAh 70A

$4.45

4000mAh ultra-high discharge 21700 tabless cell with 70A CDR and 140A pulse. One of the most powerful 21700 cells available. Ideal for power tools e-bikes and drones.

390 in stock

SKU: AMPACE-JP40 Category: Tags: , , , , , ,

Ampace INR21700-JP40 – Ultra High Power 21700

Engineered for maximum current delivery. 70A max CDR with tabless full-tab design. Praised by independent testers for consistent real-world performance.

Technical Specifications

Specification Value
Format 21700
Nominal Capacity 4000mAh (3900mAh min)
Nominal Voltage 3.7V
CDR 70A (temp-limited 80C)
Pulse Discharge 140A (5s)
Chemistry NMC
Design Tabless (Full-Tab)
Internal Resistance 4mOhm ACIR
Charge Current 8A max (2C)
Weight 70g
Dimensions 21.3mm x 70.4mm
Discharge Temp -30C to 75C

Safety Warning

Unprotected cell. Always use with a BMS. Never short-circuit or overcharge. Keep away from fire and extreme heat. Not for use in e-cigarettes or similar devices.

Cell Specification

Item Specification and comments
Cell model AMPACE 21700A (JP40) – cylindrical Li-ion rechargeable cell
Standard discharge capacity ≈4000mAh – Charge: 0.5C (2A) to 4.20V, CV to 0.02C (80mA) @25±2°C; Discharge: 0.2C (0.8A) to 2.5V @25±2°C
Rated discharge capacity (10C) ≈3900mAh – same standard charge, discharge at 10C (40A) to 2.5V @25±2°C
Nominal voltage 3.7V
Standard charge 0.5C (2A) CC to 4.2V, then CV at 4.2V until current ≈80mA
Rated charge 2C (8A) CC to 4.2V, then CV at 4.2V until current ≈200mA
Charging time Standard: ≈140min (80mA cut-off); Rated: ≈40min (200mA cut-off) @25±2°C
Standard discharge 0.2C (0.8A) CC to 2.5V
Max. continuous discharge current 45A without triggering 80°C cut-off; 60A with 80°C temperature cut
Max. pulse discharge current 140A for 5s @25±2°C
Charge cut-off voltage 4.2V
Discharge cut-off voltage 2.5V
Cycle life (high-rate, 30A) ≈2400mAh after 600 cycles (≈60% of standard capacity) with rated charge and 30A discharge to 2.5V @25±2°C
Cycle life (high-rate, 40A) ≈2400mAh after 400 cycles with rated charge and 40A discharge to 2.5V (with temperature management) @25±2°C
Retention characteristics Capacity recovery ≈3600mAh (≈90%) after 30 days storage at 60±3°C, rated charge then 0.2C discharge to 2.5V
Initial impedance ≈4mΩ (AC 1kHz at shipment voltage 3.50–3.59V)
Operating cell surface temperature Charge: -10~60°C (recommended recharge release <45°C); Discharge: -30~75°C (must re-discharge release <60°C)
Storage conditions 0~60°C within 1 month; 0~45°C within 3 months; 0~25°C within 12 months; Humidity ≈75%RH
Shipment voltage 3.50–3.59V
Cell weight ≈70.0g
Cell dimensions (with sleeve) Height ≈70.42mm; Diameter ≈21.31mm

 

Download Manufacturer data sheet

Battery Safety

Battery Safety & Product Disclaimer

Read before purchasing or using any rechargeable lithium-ion battery.

Rechargeable lithium-ion batteries are high-energy devices that require proper handling and technical knowledge. Improper use can lead to fire, explosion, thermal runaway, serious injury, property damage, or death.

By purchasing products from CH-AmpX, you acknowledge these risks and agree to use all battery products responsibly and in accordance with manufacturer specifications.

Read the Complete Battery Safety Guide

Is This Product Right for You?

CH-AmpX battery cells are intended for:

  • Professional battery pack builders
  • Engineers and product developers
  • Industrial applications
  • Qualified hobbyists familiar with lithium-ion battery technology

These cells are designed to be integrated into battery packs protected by an appropriate Battery Management System (BMS) or Protection Circuit Board (PCB).

They are not intended for standalone consumer use, vaping devices, e-cigarettes, or any application lacking proper battery protection.

Before Every Use

Always inspect every battery before charging, installing, or transporting it.

Do not use any battery that shows signs of:

  • Damaged or torn PVC wrapping
  • Missing insulator ring
  • Dents or crushed casing
  • Swelling or bulging
  • Leakage
  • Corrosion
  • Burn marks or overheating

Using a damaged cell significantly increases the risk of battery failure.

Safe Charging Practices

Battery safety begins with proper charging.

Always:

  • Use a charger designed for lithium-ion batteries.
  • Confirm the charger matches the battery's voltage specifications.
  • Charge on a non-flammable surface.
  • Monitor batteries while charging.

Never:

  • Overcharge or over-discharge a battery.
  • Leave batteries charging unattended.
  • Charge damaged cells.
  • Use incompatible charging equipment.

Safe Storage & Transportation

Improper storage is one of the leading causes of accidental battery incidents.

Never carry loose batteries in:

  • Pockets
  • Backpacks
  • Purses
  • Toolboxes
  • Bags containing metal objects

Contact with keys, coins, tools, or other conductive materials can create a short circuit capable of causing severe burns, fire, or explosion.

Always transport batteries inside protective, non-conductive battery cases.

Store batteries in a cool, dry environment away from excessive heat, moisture, and direct sunlight.

Understanding Thermal Runaway

Thermal runaway is a rapid chain reaction that causes a battery to generate excessive heat, potentially resulting in venting, fire, or explosion.

It may be caused by:

  • Overcharging
  • Short circuits
  • Physical damage
  • Excessive temperatures
  • Internal battery failure

Reducing these risks begins with proper charging, careful handling, and correct battery storage.

Never Do the Following

To reduce the risk of injury or property damage, never:

  • Short circuit a battery.
  • Crush, puncture, or modify the cell.
  • Expose batteries to fire, water, or excessive heat.
  • Charge or discharge outside the manufacturer's specifications.
  • Dispose of lithium-ion batteries in household trash.

Recycle batteries only through approved recycling facilities.

If a Battery Fails

Immediately stop using any battery that becomes unusually hot, swells, leaks, hisses, or emits smoke.

If it can be done safely:

  • Move the battery to a non-flammable surface such as concrete or sand.
  • Keep it away from combustible materials.
  • Allow the battery to cool from a safe distance.

For lithium-ion battery fires, an ABC dry chemical extinguisher may be used. Large amounts of water may also be effective for cooling lithium-ion cells and helping prevent fire spread. Continue monitoring the battery after the incident, as damaged cells may reignite.

If the fire cannot be safely controlled, evacuate the area immediately and contact emergency services.

CH-AmpX Product Disclaimer

CH-AmpX supplies lithium-ion batteries and battery components intended for knowledgeable users and professional battery pack builders.

Customers are responsible for ensuring that all batteries are used, charged, stored, transported, and installed according to manufacturer specifications, industry best practices, and applicable regulations.

CH-AmpX shall not be held liable for any injury, property damage, equipment failure, financial loss, or other damages resulting from:

  • Improper handling or misuse
  • Incorrect charging practices
  • Unauthorized modification
  • Improper storage or transportation
  • Failure to follow recommended safety procedures
  • Use outside manufacturer specifications

By purchasing from CH-AmpX, you acknowledge the inherent risks associated with lithium-ion batteries and accept full responsibility for their safe handling and use.

View Complete Safety Guide
Weight 0.155 lbs
Dimensions 2.772 × 0.839 × 0.839 in

Reviews

There are no reviews yet.

Be the first to review “Ampace JP40 21700 4000mAh 70A”

Your email address will not be published. Required fields are marked *

Related products