The type of battery used in the hearing aids are nickel metal hydride. The charger has a lithium ion battery. You can read more about the overall life expectancy here.
Power Supply Specifications: Input: 100-240V ~ 50/60 Hz, 200mA max current. Output: 5.0V …1100mA
When traveling, simply connect your charger plug to the correct international adapter to charge. You can also plug the larger, USB-A end of the cord directly into a USB wall outlet to charge. Your hearing aid system can be used on an aircraft, as hearing aids are exempt from the rules applied to other personal electronic devices.
Proper storage of your Eargo devices will increase their lifespan and keep them in top working condition. When not in use, store them in the charger. This will keep them fully charged. Please try to avoid dropping your Eargo devices or your charger onto any hard surfaces.
As with many batteries, Eargo device batteries have a risk of leakage. Periodically check Eargo devices for any signs of leakage (visible white residue). If you see such residue or suspect battery leakage for any other reason, immediately discontinue use and contact Eargo immediately. If you suspect you have touched any battery fluid or residue, wash your hands thoroughly.
NATIONAL BUTTON BATTERY INGESTION HOTLINE: 1 (800) 498-8666
Batteries are dangerous if they are swallowed. To help prevent accidental ingestion of batteries, keep your hearing devices out of the reach of children and pets and never put your hearing device in your mouth.