Charging the Apple Watch using its 6-pin accessory port

Over the last month Reserve Strap, who are planning on making an Apple Watch accessory strap with a built-in battery, has performed charging via the 6-pin accessory port of the Apple Watch in a variety of conditions. Reserve Strap made a short video documenting a charging speed test they performed between the Apple Watch wireless charging cord and our own 6-pin accessory port charging.

Some interesting observations were:

– Charging using the 6-pin accessory port is slightly faster than wireless inductive charging.

– No charging icon appears on the Apple Watch during 6-pin accessory charging. This is likely to avoid unnecessary screen clutter when using smart bands. We’re accounting for this by including a simple LED on the Reserve Strap to indicate charging state.

– While not apparent in the video, there was less ambient heat radiated on the back of the Apple Watch using 6-pin accessory port charging compared to wireless induction.

MacDailyNews Take: Again, we’d be really careful with using undocumented, unsupported ports as Apple could change how that port works at any time. Plus, we’ve pounded on our Apple Watches all day long and have never needed to recharge before putting it to bed at night. Battery life is simply not an issue.

(UPDATE: Of course, battery life would be an issue for camping, backpacking, etc., as MacDailyNews reader John points out below, but we’d recommend using any of the thousands of battery backup solutions that provide a standard USB port allowing for the use of Apple Watch’s Magnetic charging cable. (For example: Duracell Instant USB Charger (US$7.89) or Cottee 5000mAh Solar Battery Panel Dual USB Port Rain-resistant, Dirtproof and Shockproof Portable Charger Backup External Battery Pack Power Bank ($11.60) or Voltsaf External Battery Pack Backup Charger ($35.97) or similar.)


Third-party Apple Watch battery straps likely not to work – April 27, 2015
Developers: Leave Apple Watch’s diagnostic port alone! – May 11, 2015
Apple Watch’s hidden port a goldmine for developers, accessory makers – May 4, 2015


  1. I used to travel internationally extensively and was frequently in situations of being away from charging ports for 36 – 48 hours. I have friends who do that now. An active strap would be ideal for this kind of situation. Of course, if we were all rich, we could afford a $10,000 airline seat with charging port and use the executive lounges, but without those two amenities, an active strap would be just great.

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