These batteries come from battery packs from broken scooters, tested and still has more than 2500mAh of capacity.
Taken from Ninebot and Xiaomi scooters battery pack
Capacity: 2550mAh
Nominal Voltage 3.6V - 3.7V
Charging cycle end voltage 4.20V ± 0.05V
max. Discharge current: 7.65A
Do not discharge deeper than 2.5V
Plus pool: Flat Top
Chemistry: INR - LiNiCoMnO2
Protection circuit: Without
Diameter: 18.5 mm
Height: 65.3 mm
Weight: 50g