UPDATE: The model below is now sold out, but a similar charger with solid reviews is available for $39.99.

EARLIER: Whether you have the original Apple Watch or a newer model like the Apple Watch Series 3 or Series 4, there’s one accessory that you absolutely must have. It’s called the Capshi Portable Apple Watch Charger, and it does exactly what the name implies. This little charger is the size of a keychain but it packs a 700 mAh battery with enough juice to charge your watch about twice before needing to be recharged itself. It’s fully MFi certified so you don’t have to worry about low-quality magnetic charging discs, and it’s only $45 on Amazon right now.

Here are the bullet points from the product page:

  • [ MFi Certified] :Built-in MFI certified(PPID:229515-0125.)magnetic charging module, Apple has tested this charger and certified it’s safe to use with all versions of the Apple watch. Your watch is protected from over-current, over-charging and over-heating.
  • [Made for all Watch]: Compatible for all 38/40/42/44 mm Apple Watch models; Apple Watch Series 4/3 / 2 / 1, Apple Watch Sport, Apple Watch Nike+, Apple Watch Hermès, Apple Watch Edition.
  • [Portable Charger for Apple Watch]: Built in 700 mAh lithium ion battery,Wireless Charger Power Bank for Apple Watch enables convenient, cordless charging at home and on the go,attatched to a ket ring,which is the perfect solution to Apple Watch users who are traveling,Portable,lightweight and easy to carry around.
  • [ Watch Magnetic Charging Module]: Strong magnetic adsorption allows you to adjust the angle freely without deviating from the charger center.Easy to use,Press the power button and set your watch on the magnetic circle. 4 LED lights tell you the status of the charge.
  • [Guaranteed Safety]: Premium construction and circuitry with CE, FCC & RoHS certification protect you and your device. Support 1 Year Warranty, 30 Days Money Back about iwatch chargers.

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