The Keeppower S1 Li-ion Rechargeable Battery Charger is a compact, highly efficient charging solution designed specifically for users who rely on high-performance rechargeable batteries. Engineered with precision and reliability in mind, the S1 model features a single-slot design that is ideal for charging one battery at a time, making it perfect for both home and travel use. Its straightforward functionality, combined with smart safety features, ensures that users can charge their batteries quickly and securely without unnecessary complexity.

The charger operates with an input of DC 5.0V at 2.0A, which can be conveniently supplied by a variety of sources including USB power adapters, laptops, and power banks. This flexibility allows users to charge their batteries almost anywhere, whether they are at home, in the office, or out on an adventure. The output of the charger is 4.20V at up to 2.0A, optimized specifically for Li-ion rechargeable batteries, ensuring a fast and safe charging process.

Compatible with a wide range of Li-ion battery sizes, the Keeppower S1 supports the charging of popular formats such as 32650, 26800, 26700, 26650, 21700, and 18650. This broad compatibility means that the S1 can handle nearly any high-capacity cylindrical battery commonly used in flashlights, vaping devices, and portable electronics. For smaller batteries such as 18350, 16340, 14650, 14500, 14430, and 10440, the S1 is also suitable, provided users select the appropriate charging current for optimal battery health.

Monitoring the charging process is made simple through the integrated LED indicator lights. During charging, the LED glows red, providing a clear visual confirmation that the battery is being charged. Once charging is complete, the LED changes to green, signaling that the battery is fully charged and ready for use. This intuitive system helps prevent overcharging and encourages users to remove the battery promptly once it is fully charged, preserving the lifespan of both the battery and the charger.

Safety is a key aspect of the Keeppower S1’s design. Users can easily select the desired charging current by pressing the button once. Choosing the correct current is important to ensure safe and efficient charging, with recommendations clearly outlined: a 0.5A current is suggested for smaller batteries like the 18350, 16340, 14650, 14500, 14430, and 10440 sizes, while a 1.0A current is recommended for mid-sized batteries such as the 26650, 18650, 18500, 17670, 17500, and 16650. For the highest capacity batteries like the 26650 and 18650, a 2.0A current can be selected, although this maximum output is available only when charging a single battery.

An additional safety feature includes the charger’s error indication system. If a battery is inserted incorrectly, the charger displays an "Err" message, alerting the user to reverse the polarity before charging can proceed. This protective measure prevents potential damage to both the battery and the charger itself.

The Keeppower S1 also features intelligent time measurement during the charging process. In the first 60 seconds after starting the charge, the elapsed time is displayed in seconds, allowing precise monitoring of the initial charging phase. After 60 seconds, the display switches to measuring time in minutes, offering users an easy way to track the overall duration of the charging session.

With its efficient design, robust safety features, and compatibility with a wide range of Li-ion batteries, the Keeppower S1 Li-ion Rechargeable Battery Charger is a must-have accessory for anyone who frequently uses rechargeable batteries. Its ability to draw power from multiple sources and its compact, travel-friendly size make it perfect for users who need a reliable charging solution both at home and on the move. Whether you are powering flashlights, electronic devices, or other battery-operated tools, the S1 charger provides a simple, efficient, and safe way to keep your batteries performing at their best.

1. Type: 1-slot Li-ion Battery Charger;
   2. Part No.: S1;
   3. Input: DC 5.0V—2.0A;
   4. Output:
   4.20V—2.0A (For Li-ion Rechargeable battery)
   5. Compatible with:
   Li-ion Rechargeable Batteries: 32650/26800/26700/26650/21700/18650
   6. Track charging status via the LED indicator lights.
   Charging: RED
   Full Charged: GREEN
   7. Charged by USB power adaptor, laptop, power bank, etc;
   
   Safety Tips:
   ● Press the button once to switch charging current.
   ● “Err” means battery polarity reverse.
   ● Charging time: In the first 60 seconds, charging time is measured
   in second. Over 60 seconds, charging time is measured in minute.
   ● 0.5A charging current: Recommend for Li-ion battery 18350/16340/14650/14500/14430/10440.
   ● 1.0A charging current: Recommend for Li-ion battery 26650/18650/18500/17670/17500/16650.
   ● 2.0A charging current: Recommend for Li-ion battery 26650 and 18650.
   2.0A is available only when there is 1PCS battery is being charged.
   ● Remove the battery when fully charged.

SHIPPING
The final shipping cost and estimated delivery timeframe will be available to you during checkout. Currently, we offer 3 International shipping methods which are steady and easy to track. Priority worldwide shipping, Premium ( Partial countries) and a faster Express shipping. The estimated times stated below are not guaranteed. An international package could experience delays like postal strikes or severe weather or Cov-19 situation. All shipping ways, PO Box address is not acceptable.

If you don’t receive your order within the estimated time frame provided below and suspect that it might be lost in transit, please contact Flashlightgo Support ( support@flashlightgo.com ) and we can look into the order with the courier. Lost-in-transit requests must be submitted to Flashlightgo Support within 3 months of the date of shipping or before the courier archives the tracking information.

Option 1.
Express by DHL/UPS/Fedex/Aramax/SF etc ( there may be tax need to pay in this way),
The estimated time of delivery is usually 3-7 work days depending on the country. Includes detailed tracking and confirmation of delivery.

Option 2.
Premium ( 6-10days, All tax and Duty Paid),
All tax and duty are prepaid to carrier by Flashlightgo before shipping, so you dont need to pay any tax or duty when you get it.

Option 3.
Priority shipping(1-2 Weeks, average 10 days)
If we marked it is with all tax and duty paid, all tax and duty are prepaid to carrier by Flashlightgo before shipping, so you dont need to pay any tax or duty when you get it.

Learn more,Please click on here.

To ensure that you get the desirable product, we allow a seven-day product return period. Any product return application outside this period will not be entertained.
All returned product must be unused and the original package should be kept.

Return：
We do not offer return for personal products like socks and hats or food, magazine and fragile or dangerous products The original receipt must be available for application of return.

Discount products：
No product return for discount products

Gifts products：
If the item is marked as a gift when purchased and shipped directly to you, it cannot be exchanged , refunded or warranty.

Exchange：
We only replace items if they are defective or damaged.
Exchange service are offered only to wrong deliveries or product damage not caused by client. If needed, please email to info@flashlightgo.com.

Warranty
How long is the warranty period?
Flashlightgo warrants to the original purchaser that the Product(s) shall be free of any defect in material or workmanship for a period of one year for labor and one year for parts from the date of the original order except the items listed below:
Chargers,Batteries and Other Accessories: 3 months warranty

Should the Product(s) supplied by Flashlightgo prove defective because of improper workmanship or material as reasonably determined by us, Flashlightgo agrees, at its option, to either repair or replace the Product free of charge, excluding any shipping or handling charges.

Learn more,Please click here.