How long does a charge keep the mug warm?

The listing does not state a runtime. Expect a few hours per charge at a keep-warm temperature rather than all-day heat, and plan to redock the base between cups.

Is the mug dishwasher safe?

Treat it as hand wash only. The ceramic cup is fine, but the heating element and battery in the base should not go through a dishwasher.

Can I use the mugs without the heating base?

Yes. They are ordinary 18 fl oz ceramic mugs, so they work normally; the self-heating base is what adds the keep-warm function.

What comes in the set?

Two ceramic mugs, one jasmine white and one gray, with the self-heating base hardware. Check the listing for whether each mug gets its own base or they share one.

How does this compare with an Ember mug?

Ember sells single mugs with app temperature control and a stated battery life. This set gives you two larger ceramic mugs, but it publishes no runtime or temperature settings, so check those before choosing.