Thanks for posting and welcome to the Bose Community.
So that we can assist you with your question, can you please confirm which case you are referring to? If you could link the product this would be very helpful.
I look forward to hearing back from you.
Hector B - Community Support
Thanks for making us aware of this!
The SoundSport Charging case will not be able to charge the SoundSport Free charging case, this is due to the products not being compatible.
If you have any other questions, please do let us know.