Ok, so you’ve got a MacBook Pro and you need a battery pack, the main issues are:
- For the older MacBooks, getting something with a Magsafe connector.
- For the MacBook 2016 and later, you need something that does high speed USB C charging. Most chargers will charge at 5V x 2A or 10 watts, but these machine needs more like 60 watt for the smaller ones or 86 watts for the 15″ MacBook Pros.
- Your Windows laptop with a proprietary connector
Here are some good choices:
- BixPower 12V and 19V output with multiple tips. These work  with laptops with different inputs. So that you don’t have to up convert and downconvert them.
- RavPower USB C Battery Pack. For MacBook Pro 2016 and later, This supports up to 30W recharging, so not quite 10 watts, but about 3 times faster.
- Lizone QC Battery and Lizone 5 pin to MaBook Pro 2015 or earlier. This connects a Lizone battery directly to the a MacBook, they use a proprietary 5 pin, but they do have a Magsafe adapter.
- Chargetech AC Outlet Battery Pack. The most expensive option at $200 plus, but this has an inverter, so you can plug in anything that needs AC power up to 87 watts. It is also not as efficient as DC-to-DC but the faster charger of all.