This is a compact, inexpensive and very portable device designed with cost and ease of use in mind. Gold plated contacts resist corrosion and assure perfect connection with USB jack. Hand-assembled at LWE's shop in Pennsylvania USA, each unit is tested before packaging.

operation:

  • 1: Insert the depleted LR20nn cell into the battery holder on the underside, with the cell's negative contact facing down, as with most coin cell holders.
  • 2: Plug the device into a live USB type A jack. (this device uses only the USB power contacts and will not register as a USB device)
  • 3: The white light will come on, indicating power is available to the device.
  • 4: The red light will come on, indicating that the battery is being charged.
  • 5: When the battery is fully recharged, the red light will go off and the blue light will come on.
  • 6: Remove the device from the USB jack, and remove the recharged cell from the battery holder. Do not remove the battery before unplugging the charger.
troubleshooting:
  • white 'power on' light does not come on:
    ‣ Check that the USB jack is powered at 5 Volts.
    ‣ The device may be inserted upside-down. Try turning it over.

  • all three lights come on:
    Unplug the device from the USB jack at once.
    ‣ Check that the battery is properly inserted.
    ‣ The battery may be exhausted and incapable of being recharged. Check with a VOM to see if the cell's resistance is less than 75 MΩ.

  • battery is not recharged after more than 2 hours:
    Unplug the device from the USB jack.
    ‣ The battery may be exhausted and incapable of being recharged. Check with a VOM to see if the cell's resistance is less than 75 MΩ.
precautions:
  • Do not use this device to recharge Maxell / Renata / FDK et'c ML2032 / ML2016 rechargeable Lithium cells, or similar cells with a nominal output voltage lower than 3.6 Volts. Those cells are designed for a voltage much lower than the recharge voltage of this device. Using this device to recharge ML20nn cells may result in battery explosion and / or damage to the device.

  • Do not use this device to attempt to recharge CR2016 / CR2025 / CR2032 cells or any other disposable cells. Those cells are not designed to be recharged. Using this device with CR20nn cells may result in battery explosion and / or damage to the device.

  • Do not plug this device into a USB jack without first inserting a battery. Operating this device without an appropriate battery in the battery holder may damage the device.

  • Do not insert the battery 'upside down' with the negative contact facing out. The battery will not charge. Doing so may damage the device.

  • Do not stack two 16mm cells in the battery holder. The batteries will not charge, as their combined series voltage is greated than the device's charging voltage. Doing so may also damage the device.
device specs:
supply voltage: 5 Volts USB type A jack
regulator IC: Microchip Tech MCP73831
battery charge current: 37 mA
battery charge time: 60 - 90 minutes typical
weight (without battery): ~6 grams
This device is not labeled or recommended for vehicle use, or for critical applications such as medical equipment or military applications. Applying this device in such applications will void the Warranty. Buyer assumes all risk for off-label application. Contact the Seller for details.

This device has been assembled by hand. Small cosmetic imperfections may be evident.... Read more »