3.7V to 5V/9V Adjustable Boost Converter Module, 18650 Li-ion Battery Charging & Discharging Integrated Power Supply Board, 2A Output.

This module is a single-cell 3.7V lithium battery charger + boost converter. It charges a 18650 lithium battery through USB-C and can boost the battery voltage to an adjustable output between 4.2V and 28V. The maximum charging current is 1A, and the discharge/boost output is rated up to 2A (depending on input voltage, output voltage, and cooling conditions).

Product Parameters
1A programmable lithium battery charging and discharging current
Suitable for a single 3.7V lithium battery, fully charged at 4.2V

Constant-current / constant-voltage charging with temperature protection
Soft startup prevents current surges and extends battery life

Low power consumption, helping prolong battery usage time
Dual charging status outputs; battery-free and fault status indication
UV activation, supports trickle charging from 2.9V

Operating temperature: -40°C to 80°C
Input voltage range: 4.2V–6.5V
Output voltage adjustable: 4.2V–28V.