This DIY kits battery need Soldering battery or connect the battery to the charge board by yourself. The maximum output current is 2.1A and minimum output current is 1A. Both sides of the charging port will be based on how much current the smart phone receives the output number, so no need to consider which port should be used when charging your mobile phone.
1. 3 Led Indication Lights 2. Input: 5.0V /1A 3. Output voltage: 5.0V 4. Output current: 1A / 2.1A 5. Capacity: Can be installed 4 x 18650 3.7V 6. Dimensions: 107 x 70 x 25 (mm)