3.7V 4.2V MPPT Solar Charge Controller 18650 Li-ion-ion Battery Module 1A 5V
6: Two options, no needle and with needle. If there is no special welding tool, choose with pin. If you want to change the pin direction, choose without pin. The maximum charging current/output current is 1A, but you can change the current by changing the value of the R1 resistor.