[Inquiry] Razer Pokemon Wireless Earbuds - Battery differ between Left & Right

Regarding Razer Pokemon Wireless Earbuds, is it normal that there's a big difference in battery level between Left and Right? Both fully charged, but when Left notified low battery (10%), Right still got 60% according to Razer app and my phone - Left only lasted 2hr+ while Right lasted 4hr+ before battery dead. Tried a few times and confirmed that Left's battery consumed faster than Right's (too much difference), is my Left defected??