Doublepow UK03 Single Slot Battery Charger – USB Smart Charger for 3.7V/4.2V Li-ion Batteries 26650 18650 14500 10440 16340 21700 18500
Description
Description
The Doublepow UK03 is a single slot USB smart Li-ion battery charger designed for 3.7V/4.2V cylindrical lithium batteries. Featuring an upgraded spring-loaded compartment with free expansion, it is compatible with 26650, 18650, 14500, 10440, 16340, 21700, 18500, and more—truly one charger for multiple battery types. The built-in intelligent LED indicator shows red while charging and automatically turns green when fully charged, preventing overcharge. It also features six-fold protection: overcharge, short circuit, over-current, over-power, temperature, and over-voltage protection for safer use.
The charger uses USB power input, compatible with power strips, computers, car chargers, and other power sources for charging anytime, anywhere. The back features a USB cable slot with an ergonomic design for easy storage. Measuring 133×35×40mm and weighing only 45g, it is compact and portable—ideal for home, office, and outdoor use.
Key Features
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Single Slot Design: Charges one battery at a time, ideal for daily spares and replacements
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Upgraded Spring Compartment: Free expansion, compatible with multiple battery sizes
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One Charger for Multiple Batteries: Supports 26650, 18650, 14500, 10440, 16340, 21700, 18500, and more
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Intelligent LED Indicator: Red while charging, green when fully charged, preventing overcharge
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Six-Fold Protection: Overcharge, short circuit, over-current, over-power, temperature, and over-voltage protection
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USB Portable Charging: Supports power strips, computers, car chargers, and more
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USB Cable Slot: Back cable slot for easy storage
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One-Year Warranty: Worry-free after-sales service
Parameters
| Parameter | Specification |
|---|---|
| Brand | Doublepow |
| Model | DP-UK03 |
| Product Name | 3.7V Cylindrical Li-ion Battery Charger |
| Input | 500~1A |
| Output | 4.2V ⎓ 800mAh |
| Weight | 45g |
| Dimensions | 133 × 35 × 40mm |
| Charging Method | USB Charging |
| Indicator | Red while charging, green when fully charged |
| Protection | Overcharge, short circuit, over-current, over-power, temperature, over-voltage |
| Compatible Batteries | 26650, 18650, 14500, 10440, 16340, 21700, 18500 and other 3.7V/4.2V Li-ion batteries |
| Warranty | One Year |
| Standard | GB4706.18-2014 |
Applications
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Home daily charging: Charging Li-ion batteries for flashlights, remote controls, electric toys, and more
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Office backup: Charging batteries for portable devices, vape devices, etc.
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Car charging: Connecting to car USB ports for on-the-go charging
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Outdoor travel: Pairing with power banks for charging anytime, anywhere
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DIY battery pack maintenance: Charging cells before assembling battery packs
FAQ
Q1: What batteries can this charger charge?
A: Compatible with 26650, 18650, 14500, 10440, 16340, 21700, 18500 and other 3.7V/4.2V Li-ion batteries.
Q2: What is the charger’s output current?
A: Single slot output is 800mAh. Input current depends on the charging head you use—1A input with a 1A head, 2A input with a 2A head.
Q3: How does the charger display charging status?
A: The indicator shows red while charging and automatically turns green when fully charged, preventing overcharge.
Q4: What protection features does this charger have?
A: It features six-fold protection: overcharge, short circuit, over-current, over-power, temperature, and over-voltage protection.
Q5: Can this charger charge dry batteries?
A: No. This product is only suitable for 3.7V/4.2V Li-ion batteries and cannot charge dry (disposable) batteries.
Q6: How is the charger powered?
A: It uses USB power input, compatible with power strips, computer USB ports, car chargers, and other power sources.
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
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
Security

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.
