Soundcore AeroFit 2 is a new Open-Ear True Wireless Earbuds released by Anker recently. A recent teardown reveals its integrated battery. The earbuds has li-polymer battery with model number 74185PF3 and capacity of 70mAh and votage of 3.8V. There is also a battery inside the charging case to offer additional power for the earbuds. The battery has a model number 632834PN38, with capacity of 750mAh and voltage of 3.7V instead.
Sanag M13 Pro Wireless Bluetooth Smart Portable Speaker has a very simple 18650 battery with only capacity of 1800mAh. Normally a 18650mAh battery has at least 2200mAh, so it is quite strange that Sanag M13 Pro is equiped with a 1800mAh battery. However Sanag claims that its battery can provides up to 20 hours of playback.