DMEGC 40P 21700 Battery 2Pcs - 4000mAh 30A High Drain High Power (21700-40P)
Description
Unleash High-Power Performance
Unleash high-power performance with the DMEGC 40P 21700 Battery 2Pcs (Model: 21700-40P). Engineered by DMEGC (Dongyang Magnetic Materials), a leading Chinese lithium-ion cell manufacturer, these 21700 batteries deliver a solid 4000mAh capacity combined with an impressive 30A continuous discharge (up to 60A pulse). Designed for high-drain applications, the DMEGC 40P is the perfect choice for power tools, high-performance e-bikes, drones, and other demanding devices that require explosive current output without compromising reliability. This listing includes two individual cells (not pre-assembled), giving you the flexibility to build custom battery packs in series or parallel configurations for your specific high-power projects.
Key Features
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High 30A Continuous Discharge
Built for high-power demands. Delivers a massive 30A continuous current output under heavy loads, making it ideal for the most power-hungry devices. Supports up to 60A pulse discharge for short bursts of maximum power. -
Solid 4000mAh Capacity
Offers a healthy 4000mAh capacity while maintaining its incredible high-drain capability, providing a practical balance between runtime and raw power output. -
Ultra-Low Internal Resistance
Engineered for minimal energy loss during high-current discharge, generating less heat and ensuring maximum power delivery to your device. -
Authentic DMEGC Quality
Premium-grade 21700-40P cells from a reputable manufacturer, ensuring excellent cycle life, safety certifications, and consistent voltage stability under extreme loads. -
Flat Top Design
Standard flat top configuration, compatible with most battery holders, spring-loaded contacts, and DIY battery pack builds. -
2-Pack Value
Supplied as two individual cells, allowing you to build a 2S series pack (7.2V), a 1S2P parallel pack (8000mAh), or replace worn-out cells in pairs for balanced high-power performance. -
High-Power Specialized
Specifically optimized for high-drain devices like power tools, high-performance e-bikes, drones, and advanced electronic mods, where standard cells would struggle.
Technical Parameters
| Parameter | Value |
|---|---|
| Brand & Model | DMEGC 21700-40P |
| Battery Type | Lithium-Ion (Li-Ion) |
| Size | 21700 (Diameter 21mm, Height 70mm) |
| Capacity | 4000mAh (Minimum 3900mAh) |
| Nominal Voltage | 3.6V |
| Full Charge Voltage | 4.2V |
| Cut-off Voltage | 2.5V |
| Continuous Discharge Current | 30A |
| Pulse Discharge Current | Up to 60A (not for continuous use) |
| Internal Resistance | ~12-15mΩ (Typical) |
| Positive Terminal | Flat Top |
| Protection Circuit | No (Unprotected Flat Top Cell) |
| Operating Temperature | -20°C to 60°C |
| Quantity in Package | 2 Pcs (2Pcs) |
Applications
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High-Performance Power Tools
Upgrading cordless drills, impact wrenches, angle grinders, and chainsaws to handle the toughest jobs without bogging down. Two cells can power smaller tools or be used in a larger pack. -
Heavy-Duty Electric Bikes (E-Bikes)
Building or upgrading battery packs for high-torque motors, steep terrain riding, and demanding off-road e-bike applications. Two cells are a great start for a custom pack. -
High-Performance RC Models & Drones
Powering 1/8th or 1/10th scale buggies/truggies, large drones, and other RC vehicles requiring brutal current spikes. -
High-Drain Tactical Flashlights
Fueling high-lumen searchlights and tactical flashlights that demand massive current for ultra-bright output. Many tactical lights use two 21700 cells. -
Custom DIY Battery Packs
Building 2S, 3S, 4S, or larger high-power packs for robotics, e-skateboards, or portable heavy-duty tools.
FAQ
Q1: Does "2Pcs" mean it's a 2S battery pack assembled together?
A: No. "2Pcs" means you will receive two separate individual cells. You will need to assemble them in series (for 7.2V), parallel (for 8000mAh), or a specific configuration based on your device's requirements.
Q2: How does DMEGC 40P compare to Samsung 40T?
A: The DMEGC 40P offers very similar performance to the Samsung 40T. Both have 4000mAh capacity and 30A+ continuous discharge. The DMEGC 40P is generally more affordable, making it an excellent cost-effective alternative for users who want high-power performance without the premium price tag.
Model Comparison Table
| Brand | Model | Capacity | Continuous Discharge | Best For |
|---|---|---|---|---|
| DMEGC | 40P | 4000mAh | 30A | High power (budget-friendly) |
| Samsung | 40T | 4000mAh | 35A | High power (premium) |
| DMEGC | 50E | 5000mAh | 15A | Balanced (medium-drain) |
| DMEGC | 45E | 4500mAh | 10A | Long runtime (low-drain) |
Q3: Can I use these two cells to build a battery pack for my E-Bike?
A: A single 3.6V cell (or two cells) is not enough for an e-bike (which typically requires 36V, 48V, or 52V). Two cells can be combined in series to create a 7.2V pack, suitable for small devices like some flashlights or RC models. For an e-bike, you need many more cells wired in series. The DMEGC 40P is an excellent choice for high-performance e-bike packs due to its 30A discharge. Always consult a professional if you are unsure about building a pack.
Q4: Does this battery have a protection circuit (PCB/BMS) built-in?
A: No. The DMEGC 40P is an unprotected flat-top cell. It relies on the external device or a BMS (Battery Management System) to handle overcharge, over-discharge, and short-circuit protection.
Q5: What charger should I use?
A: Use a dedicated intelligent Li-Ion charger designed for 3.6V/4.2V cells. Ensure the charger supports the correct voltage for your specific pack setup (e.g., 1S charger for single cells, 2S charger for 2 cells in series, etc.).
Q6: How do I identify positive and negative terminals?
A: The flat top (the side with the DMEGC logo and model number) is the Positive (+) terminal. The bottom (the side with the shiny metal casing and a slight indentation) is the Negative (-) terminal.
Q7: Is DMEGC a reliable brand?
A: Yes. DMEGC (Dongyang Magnetic Materials) is a well-established Chinese manufacturer with significant experience in lithium-ion cell production. While not as globally recognized as Samsung or LG, their cells offer solid performance, good safety standards, and excellent value for money.
Shipping and Returns
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Free Shipping: Enjoy free shipping on all orders over $65. For orders under $65, the shipping cost is $8.99.
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Delivery Time: Once shipped, orders typically arrive within 7–15 business days.
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Easy Returns: We want you to be completely satisfied. If you're not, you can return your product within 30 days of receiving your order. Please ensure the items are unused and in their original condition. For return instructions, please contact our support team.
Payment & Security
Payment methods
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Security
Both cells arrived at 3.48V and 3.51V, which is fine. After 5 cycles their internal resistance differed by 2m¦¸. Still usable for paired applications.
I run these in a regulated mod, 75W all day. At 30A they barely get warm. Better than my old 25R stock.
Loaded with a constant 30A resistive load, voltage held above 3.5V for most of discharge. Temperature peaked at 62¡ãC. Safe and sturdy.
In my charger's capacity test, one cell showed 3870mAh, the other 3920mAh. Still plenty for my drone, but not quite 4000mAh.
Used these in my high-drain flashlight, constant 30A output without voltage sag. Runtime matches the 4000mAh claim closely.
Refund Policy
OneAndes Return & Refund Policy
At OneAndes, we are committed to providing high-quality cylindrical lithium-ion batteries for your drones, vacuums, garden tools, and other power needs. If you are not completely satisfied with your purchase, we are here to help. Please read our full return policy below before initiating a return.
1. Return Window
You have 30 calendar days from the date you received your item(s) to request a return. Any return request submitted after 30 days will not be eligible for a refund or exchange.
2. Eligibility Conditions
To qualify for a return, all items must meet the following conditions:
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Condition: Items must be unused, undamaged, and in the same condition that you received them.
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Packaging: Items must be returned in their original packaging with all accessories, manuals, and protective covers intact.
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Proof of Purchase: A valid receipt, order confirmation email, or proof of purchase must accompany all returns.
Non-Returnable Items:
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Batteries that have been installed, used, or show any signs of wear.
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Items marked as “Final Sale” or “Clearance” at the time of purchase.
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Customized or special-order products.
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Gift cards.
If a returned item fails to meet these conditions, we reserve the right to deny the return or charge a restocking fee.
3. How to Initiate a Return
Follow these steps to return your product:
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Contact Us: Email our support team at support@oneandes.com with your order number and the reason for return. We aim to respond to all return requests within 24 hours on business days.
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Receive RMA: We will provide you with a Return Merchandise Authorization (RMA) number and return instructions. Do not ship any item without an RMA number.
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Pack Securely: Place the item in its original packaging, include all accessories, and clearly write the RMA number on the outside of the box.
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Ship to Our US Warehouse: Ship the package to the following address:
OneAndes Returns
10320 6th St
Rancho Cucamonga, CA 91730
USA*Important: Lithium-ion batteries are classified as hazardous materials (Class 9). Please follow the shipping guidelines provided in Section 4 below. We recommend using a trackable shipping service and purchasing shipping insurance, as we cannot guarantee receipt of your returned item.*
4. Return Shipping Costs
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Defective or Incorrect Items: If the item you received is defective, damaged in transit, or different from what you ordered, OneAndes will cover the return shipping cost. In this case, we will provide you with a prepaid return shipping label.
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Buyer’s Remorse / Non-Defective Returns: If you are returning an item for any other reason (e.g., no longer needed, ordered the wrong model), you are responsible for the return shipping costs. You must prepay the return shipping cost using a trackable carrier that accepts lithium batteries. We do not provide prepaid return labels for non-defective returns.
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Lithium Battery Shipping Regulations: By law, all returns must be shipped in compliance with applicable dangerous goods regulations. We will provide guidance on proper packaging and labeling. Failure to comply may result in carrier refusal, seizure, or additional fees. We are not responsible for returned items lost or rejected by the carrier due to improper shipping.
5. Refunds
Once we receive and inspect your return at our Rancho Cucamonga, CA facility, we will notify you via email of the approval or rejection of your refund.
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Approved Refunds: If approved, your refund will be processed to your original method of payment within 5 to 10 business days. Please note that depending on your bank or credit card issuer, it may take additional time for the credit to appear on your statement.
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Partial Refunds: In certain situations, only partial refunds may be granted:
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Items not in original condition, missing parts, or damaged for reasons not due to our error.
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Items returned more than 30 days after delivery (reviewed on a case-by-case basis).
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Non-Refundable Fees: Original shipping charges are non-refundable unless the return is due to our error (defective product or incorrect shipment).
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Restocking Fee: We do not charge a restocking fee for defect-free returns, but we may deduct the return shipping cost, which will be deducted from your refund.
6. Exchanges
We replace items only if they are defective or damaged upon arrival. If you need to exchange a defective item for the same product, please contact us at support@oneandes.com. Exchanges are subject to product availability.
If you ordered the wrong battery size or model, please follow the standard return process above and place a new order for the correct item.
7. Damaged or Missing Items
If your package arrives visibly damaged, please take photos of the package before opening and contact us immediately. We will work with the shipping carrier to file a claim and arrange for a replacement or refund. Damaged or missing item claims must be reported within 7 calendar days of delivery. For immediate assistance, you may also call us at (213) 316-8849.
8. Order Cancellation
You may cancel your order without penalty if it has not yet been shipped. To cancel, email us at support@oneandes.com as soon as possible. If the order has already been processed or shipped, you will need to follow the standard return process upon receipt.
9. Warranty
All OneAndes batteries are backed by a 12-month limited warranty against defects in materials and workmanship. This warranty does not cover damage caused by misuse, improper charging, unauthorized modifications, normal wear and tear, or use outside of manufacturer specifications. For warranty claims, please contact our support team.
10. Contact Us
If you have any questions about our Return & Refund Policy, please reach out:
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Email: support@oneandes.com
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Phone: (213) 316-8849 (Mon-Fri, 9 AM – 5 PM Pacific Time)
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Mailing Address: 10320 6th St, Rancho Cucamonga, CA 91730, USA
We aim to respond to all inquiries within 24 hours during business days. Please include your order number for faster assistance.