MiniMag Ostand 10K Power Bank

The 10k capacity is perfect for a full day out, and the magnetic attachment snaps on so securely I never worry about it sliding off in my bag. I was also surprised by how compact it is despite the battery size—it doesn't add much bulk to my phone at all.

The magnetic alignment is rock solid, which is exactly what I wanted for my phone, but I wish the kickstand flipped out a bit more easily. Still, 10k mAh got me through a long day with plenty to spare.