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. MDN: I agree that battery life isn’t an issue for a day of use, but I could definitely see being away from a charger for more than a day (backpacking comes to mind immediately). At that point a battery backup of some variety would come in very very handy. Just pointing that out.

    1. I would far rather change bands than have to take my watch off and put it on a charging stand. When I wake up at night, I glance at my watch. If I have restless sleep the motion tracking of the watch would be diagnostic. How Apple cannot see this is a mystery.

      1. I’m sure Apple sees this, but what’s the answer? It seems to me that if you want to use your Apple Watch to track sleeping, you’d still need to charge your watch at times when you aren’t sleeping.

      2. Damn, the MDN app really sucks. I didn’t catch the first part of your comment that you were saying Apple should provide/allow replaceable charging bands. Please disregard my comment.

  2. Leave the damn diagnostic port alone. Dammit. Mine lasts all day, every day, no matter how much I use it. I leave it to charge over night and I put it on around 5am every morning. I take it off about 10pm. If that’s not long enough for other people, then they shouldn’t by an Apple Watch. These charging bands are a waste of money.

    1. I was worried about battery life. I don’t know what battery life was like before the software update. The update was released half an hour after I received my watch and I updated it immediatly.

      I have never been less then 30% battery at night. It goes on first thing in the morning and comes off right before bed. I run 5 miles often and still my battery is never less then 30%, typically above 50%.

      As a side note, I have seen big differences between step count on my watch and iPhone. And I have noticed big differences between calorie count when running between the watch and my running app RunMeter.

  3. I love this idea. Hopefully Apple will not kill it, but rather support it. An “active” strap could add many new functions beyond battery.
    For the battery specifically, what I can’t understand is the mindset of people like “Howie” who declare that charging bands are a waste of money. Why the vitriol? There are many many use cases for having better battery life. Its great that YOU don’t need it Howie, but you don’t represent ME or others for whom this is a great idea. Again, why the anger at an option that adds functionality.
    It is sad that there are some that are so full of hate…

    1. With each new device the Apple ecosystem grows. Extending capability through an active strap could well include far more than simply charging. Apple should embrace this kind of innovation and even reward it.

  4. If you are going camping, backpacking or trekking through the mountains, why not buy a cheap plastic water proof watch with a compass attached. I really wouldn’t want to take my Apple Watch into the wilderness as it’s worth too much.

    1. Silverhawk, do you have an Apple Watch yet? They are pretty addictive: you get used to having it around, even simply as a fitness band. And they are tough and pretty waterproof too (I’ve knocked mine into all kinds of things already with nary a scratch, plus running in the rain, etc.). I see no reason to leave my watch at home when I go camping. If you choose to, wonderful, but there are definitely benefits to having it, and I plan to use mine in the back country.

  5. I’ve been using my Watch for two weeks and I don’t know about the battery issue. One thing I know is if you DON’T charge it EVERY night on the next day it WILL run out of power.

    I used it extensively for a 4.5 hour hike from 10 in the morning to 2:30 in the afternoon and on the way back home at about 6pm it went into the reserve power mode. I have the smaller 38mm Watch.

    It looks to me that overall, the Watch has “just enough” power to make it through a day. However, if you are going to use it as a fitness tracker all day- you will run out of power. That’s what it looks like to me. AND, it remote areas it looks like the iPhone draws MORE power while using it in conjunction with the Watch, less. Bottom line, I’m sticking with this statement: “the Watch has “just enough” power to make it through a day.”

    While I’m not disappointed with the watch, it is a first generation product. I’m telling my friends that unless you are either completely distracted by too many calls and messages during the day or you want the best fitness tracker on the market you should wait for gen 2.

  6. Is not that much faster, I know it was a time lapse video but in all the frames the inductive charger was just 5% behind. Is not worthy if it doesn’t make that much difference (like twice as fast).

    What could be really useful is to pack some batteries in the strap and extend the battery life of the watch.

  7. I agree I thought battery life was not a problem. UNTIL I tried the Bluetooth headphone music playback from the WATCH. That is a serious battery killer. After only an hour or two the WATCH battery had drained to almost empty.💥😱⌚️😩

      1. I have take that back. Apple must have fixed the Bluetooth battery drain problem with the 1.01 update. You can find good $125 Bluetooth headphones on sale for only about $25. You don’t need to pay full price.😃

  8. What an odd video.

    1) The conductive charge is via wires poked into the Watch, NOT via any strap.

    2) The Watch being used for conductive charging has been VISIBLY pried out of its watch shell. WTF?

    So, we’re left to wonder what this Dr. Frankenstein demo is really good for?

    I also wonder if these guys are going to get financially hosed after Apple brings down the hammer on the use of these charging straps, which OBVIOUSLY void Apple’s warranty. Oops.

    A nice experiment on their own warranty voided watch. But we’re going to join in on their experiment, and pay for it?

  9. 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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