1/2/5/10PCS 18650 Modulo di ricarica solare batteria agli ioni di litio 4,2V 3,7V 3,6V caricatore
MINI USB female chassis and the + - pads next to the power input, access to 5V. charging connection wire can not be too thin and too long. This connection resistance is large. Chip in the work of about 60 degrees heat is normal.