Integrated or non-Integrated solar battery?

Thinking about buying a foldable solar charger for your USB electronics? Should you buy one with an integrated or non-integrated battery? I get this question a lot. Here are some things to think about.

Integrated: 

• Usually more compact.
• Solar panels fold around the battery a little better.
• Fewer cords hanging out.

Non-integrated:

• You probably have a few batteries laying around the house already.
• For the same money, you usually get more solar panels.
• Less cost to upgrade to keep up with tech advancements.

Which do you like? Tell us why in the comments.