° Power is almost always stored on DC batteries.

° Converting (DC to AC, or/and AC to DC) makes you lose about 20-30% of your capacity

= Use as much DC as possible!

if you want to charge a phone from a power station. Use the USB or DC ports that is has. This can save you 20%+20% (battery DC to AC and back to phones DC)

Don’t charge a power bank, to charge a phone. Every converting step takes a bite out of your capacity

But basically all big or motor/compressor appliances run on AC and changing them to DC requires skill and time and money.