Thank you for reaching out to us and welcome to the Bose Community!
We are sorry to hear about this issue you are experiencing with your Soundlink Mini Bluetooth speaker II.
The amber light is indicating the battery is charging, however, the red light that comes on prompts you of the battery being low which tells us the battery indicator may be out of sync.
To solve this issue we recommend you try the reset all system settings, including Bluetooth device memory and language selection, and returns the product to its original out-of-box state.
Turn on the speaker, then press and hold the Power button for ten seconds. Once reset, the speaker turns off. This should clear any minor processors errors your Soundlink Mini II is facing.
If the above step does not work we recommend you reaching out to your local Customer Support Centre who will be able to assist you further. To do this follow this link, select your region, scroll to the bottom of the page and select contact us. Our team will be more than happy to help you!