The 1 A LITHIUM BATTERY CHARGING BOARD (2 pcs) is a complete constant-current/constant-voltage linear charger for single cell lithium-ion batteries.
Specifications:

1. input voltage: 4.5 to 5.5 VDC (by on-board USB connector)
2. charging current: 1 A adjustable
3. charge accuracy: 1.5 %
4. full charge voltage: 4.2 V
5. charge indicator: green = fully charged, red = charging
6. working temperature: -10°C to +80°C
7. weight: 10 g
8. dimensions : 25 x 19 x 10 mm

wpm321a4v01.pdf

ce_rohs_open.pdf