The two I mention above have been my go-tos for traveling for a long time, but they've recently been supplanted by a new entry: ElevationLab's BatteryPro.
Design and function
Designed to be part portable charger, part Apple Watch stand, the BatteryPro not only offers the most elegant and truly on-the-go charging solution I've found for the Watch, but it does so while offering a portable battery for your other electronics, too.
That portable 8000mAh battery is a large part of the Battery Pro's $99 price tag, a good $40 higher than most other watch stands in this category; it's not as full-featured as similar Mophie or Anker models — it has but a single high-speed USB output — but it's not designed to be.
The BatteryPro's primary job, after all, is being a great stand and charger for the Apple Watch. And it excels at it: It's the only portable Apple Watch charger I've seen that acknowledges what a slippery pain magnetic charging can be while on the move. The Apple Watch is designed to sit on a magnetic charger at rest; when moving, however, it takes only a slight jostle to detach the watch from its charger.
To fix this problem, ElevationLab offers a special StowStrap. It's a slightly-elastic cloth band that snaps flat against the battery in normal use, but can be unhooked and wrapped atop the Apple Watch charger to securely hold the watch in place while charging in a bag or pocket. I used this feature several times in-between games at a derby tournament last weekend; it's the only device that has reliably recharged my Apple Watch while not on a table, and for that alone, it deserves some serious props.
You can use the BatteryPro at rest, like most other chargers — just plug in the included microUSB cable and position the battery on its back or (if you want Nightstand mode) you can also pitch it up on its side. It's relatively steady, given that you're essentially propping up a half-pound battery in monolithic fashion on a table, but any major bumps or whacks to either table or battery will quickly return it to its back.
Not much to say about the charging experience itself: Like many other batteries of its ilk, the BatteryPro uses four LEDs to display charging level, and activates charging with a single press of its top-mounted red button. I managed to get a weekend's worth of charge from the battery, charging the iPhone 7 Plus and the Apple Watch at various points throughout Saturday and Sunday. I did use it briefly to keep my iPad Pro topped up, but I wouldn't recommend regularly charging an iPad unless you want to very quickly demolish its battery.
Most of the engineering and thought clearly went into this strap and the relatively compact design of the battery and Watch charger — it's not the flashiest Apple Watch stand out there, nor does it have the more protective perks or storage options of the TimePorter or Sena Watch Case. And that's okay: If you need a case to store bands or securely protect your watch when it's not on your wrist, there are other options readily available to you.