ION UBER BOOM User Manual page 5

Here are some other recommendations for getting the longest life from the internal battery.
General Usage
Storage
Repair
Disposal
ION Audio Uber™ Boom User Guide
Fully charge the battery before using it.
Avoid full discharge of the battery if possible. Li-Ion batteries are
maintenance-free, and the battery will last longest when operating
between 30–80% charged.
Do not use the product while charging the battery.
Do not charge the battery in exceedingly hot (greater than 90°F/32°C) or
exceedingly cold (less than 32°F/0°C) temperatures.
For best product longevity, do not store at exceedingly hot (greater than
90°F/32°C) or exceedingly cold (less than 32°F/0°C) temperatures.
For best product longevity, store with a 50% battery charge.
If you leave the battery level low and do not charge it for 6 months, it may
permanently lose capacity.
If the battery fails to charge, contact ION Audio at ionaudio.com.
Bring the unit to a recycling center or dispose of in accordance with local
ordinances.
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