SUPER POWER PAK
The SUPER POWER PAK was created for the purpose of being a generic power board for reclaimed lithium cells. The main design goal was to double the power rating of the original POWER PAK. The original was designed for 5V 1.5A (7.5W), and this was designed for 5V 3A (15W).
Like the POWER PAK, this went through two revisions. The first version actually performed as expected, but I swapped around the pads on a couple of components, most notably the USB A port. Thankfully, I figured that out by shorting the output with a cable that connected the ground pin to the shell and not by plugging it into something. :| V2 also reworked the ESOP-8 footprint to better fit the TP4056.
The step-up side uses the MP3424A, an upgraded version of the MP3414A from before. It's rated for 3A output and just like its little brother, it's a stout little chip that performs way better than you'd expect. Unfortunately, it's a 2x2mm QFN package, so it's a little squirrely to solder by hand. The v1 boards also didn't specify any solder mask expansion. This works fine for most things you'd hand solder, but when you work with things this small, it matters. Still, each board took a couple of attempts to get the chip properly seated.
The charging side is the extremely common TP4056. It's designed for charging at 1A, and unlike the Microchip part I used earlier, the TP4056 has a thermal pad on the bottom so it can actually do that. Both chips have significant thermal sinking to an exposed ground plane on the bottom side, which has proven entirely adequate in practice.
Continuing with the doubling theme, this board supports two outputs. One is type-C only, and the other has the option of type-C or type-A. It turns out a type-C connector will fit entirely within the footprint of a type-A connector. So that's neat.
There are also separate LED outputs for charging and done, and the NTC thermistor connection is designed to be remote. And there's now M2.5 mounting holes so it can be easily put in a case.