Moshi IonSlim 10,000 mAh (with Power Delivery)
If you're looking for one slim portable battery that can do anything, this is it. The Moshi IonSlim 10k is expensive, but it's one of the best options you can buy in 2019. Here's why.
For one, you're getting 10,000 mAh in a fairly sleek package that's wrapped in a lightweight and durable aluminum shell. There are LED lights for battery levels, and a full-size USB port that will work with any USB cable you own.
However, the USB Type-C port delivers up to 30w of power thanks to Power Delivery technology. This is enough to recharge a newer Macbook, or gives you enough juice to charge a Nintendo Switch. Most typical chargers can't push as much power as the brick coming out of your wall, so they don't work with laptops.
This one does! It actually has 10,300 mAh inside.