Dynavox T10 Speech Generating Device ( including Batteries)
The battery is integral to the device. If the device sits unused and is not charged for a lengthy period of time (a few months) the battery will go into a deep discharge state and the battery will expire. The battery may out-gas which may be described as swelled or puffed, as gas is trapped inside the pack surrounding the cells. This battery may cause the device case to separate a small amount.
Nationally
https://www.accessdata.fda.gov/scripts/ires/index.cfm?Product=Z-1304-2018