If you’re attending WWDC next week, the one piece of gear that I think is more essential to getting than any other is getting some kind of mobile batter pack for your phone. No-matter what you do — including not using it — your phone will be constantly running out of battery the entire week. It’s important — and not too late — to get one before leaving, because the local Apple Store is likely to be sold out of all but the crappiest models1. As far as type, there’s three varieties you might come across, and over the past three years I’ve now tried all three.
In 2011, I ended up getting one of this style for a good reason — I didn’t buy one before leaving and it was the only kind available at The Apple Store. It seemed practically useless, and was also pretty unwieldy. I’m not sure these are even being made for the iPhone 5, or if you’ll run across it, but if you do avoid this type as it’s going to end up being more trouble than it’s worth.
Last year, I was at least a little smarter and made a decision on what to get before leaving, and so I bought one of the case style chargers that are probably the most common. I found this style to be a big improvement over what I had the year before, and with the side benefit of being a pretty substantial case2.
It seemed to give me enough power that if I started off the day with both it and my phone fully charged, I could end the day just about running out of battery. It’s also nice, because you don’t need to do anything extra to bring it with you. The disadvantages were that it does make your phone kind of hard to pocket, it’s not enough power to last more than one day and it’s going to be useless once Apple changes the form factor of the iPhone. Because of that, I was only able to use this for a couple months until the iPhone 5 came out, and it’s sat in a drawer ever since.
This year, I sized up and bought a brick style charger. Instead of connecting directly to the iPhone at all, it’s just a brick with two USB plugs on it. It also holds about 5-6 times as much power as the case style charger I had last year, which means that it should theoretically last more than one day if I’m the only one using it3.
It does mean that I’ll have to have something to put it in wherever I go (a lot of people could probably fit it in a front pocket), but I’m likely to have my backpack with me, anyway. It does require bringing an extra cable everywhere I go, but that tradeoff bothers me less than it being worthless to me should the shape of the iPhone ever change. On The Wirecutter’s recommendation, I bought the Satechi Energy Station 10000 for $60 on Amazon (their affiliate link), but I think that any of this style with a similar capacity (10,000 MaH) that you can get before leaving should be fine.