20EA 60mAH 3X12X25mm 3.7V earphone ultra small rechargeable li-polymer battery cell with PCM 301225 lithium polymer battery Go to amazon.com Related posts Top 10 best 3.7v 60mah FeaturePCM is protect circuit board ,it can protect battery again higher or lower voltage Descriptionquite small li-polymer battery ,widely for electrical products,1C work ,charge voltage 4.2V ,discharge voltage 2.4V