I’m thinking of new things to worry about, lol. I’ve read (I should probably stop reading: no good will come from it) that battery life can be an issue.
I have a 7+. Does anyone have experience of using one at the parks? Do you use plug-in chargers, or Mophie cases? I know Disney itself offers various charging options.
I have a small Anker external charger. I don’t really use my phone in the parks though. But if I needed to, I could recharge it twice, and it’s really small.
I used a 7+ when we were there in February. I used it for pictures, FPP changes, characterlocator.com and of course to re-optimize the plans. Battery life is good but I used my power bank quite often.
At least it gives you a good feeling to have something with you to charge the battery and will be able to take pictures the whole day 
I have the same changer!
Works perfectly.
There’s definitely charging ports throughout the parks. So even if you complete go through your battery, you can plug in for a few minutes and get charged up. Thinking about it, it can be a great way to take a break and kinda just sit and enjoy the Disney ambiance. But if you want to keep on the go, a portable charging battery is your best bet (obviously).
However, something else to consider is the storage of the phone (not to add to your anxieties lol). iPhones take great video and photos, but the dang things have very limited storage (even when maxed out to 128GB). While in everyday life that makes almost no impact, for Disney, it becomes a bit of a liability. But the good news is there’s ways around it. You could use cloud services, but if you don’t want to that, there’s this thing: https://www.amazon.com/gp/product/B00AQUMZRA/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1
Charges the phone, and gives you the ability to transfer your videos and photos off the phone and onto SD Cards and/or USB Flash Drives by way of a private wifi. I used it when I went and it worked perfectly. I would set the transfer overnight and by morning everything I shot on the phone was backed up and I could then clear space on the phone. The only thing that i noticed is files that are larger than 4GB had issues transferring (so you just need to pause/resume once you get close to the file limit).
The battery size on the one I linked to isn’t that great, but I was able to fully charge my phone once on it with the battery near-depleted, which got me through the day without a problem.
So I know this is a bit of a ressurection, but I was curious how you made out in specifics to your battery concerns? I don’t think you mentioned it in your trip report.
I took an iPhone 7+ with me to WDW, and I bought a Mophie Juice Pack Air, which effectively doubles the battery life.
The Juice Pack turned out to be wholly unnecessary. I had no problems with battery life and never needed to use the Juice Pack. Nor — as others have mentioned this — did I have problems accessing or using the WDW WiFi network.
That being said, I don’t think I used my phone very much. I did take photos but tens rather than hundreds each day. I used the Disney app quite frequently to book FPPs and ADRs and to use the map.
Same with my iPhone 7 and usage of it.
I didn’t have to charge my phone two weeks ago, but I did switch it into low battery mode. I took pictures of the Christmas decorations and it hit my battery pretty hard.
