Batteries can drain while in storage so users can take them out between uses. Battery draining faster in one ear over the other could be due to one directional sound causing one to work more than the other.

Moreover, the Ear Plugs will use a low portion of battery power even when turned OFF. HEARING PROTECTIONS EARBUDS – Walker’s Silencer Digital Earbuds are an in-the-ear-canal device that both amplifies low-level sounds so you can communicate on the range, and suppresses harmful sounds to protect your hearing.