18650 LI-Ion Battery Charger and Dual USB 5V 2A Step Up Power Supply Module

This 2-in-1 module charges from 1 to 6 18650 (3.7V - 4.2V) lithium-ion batteries, and steps up (boosts) the battery voltage to the 5V dual USB outputs to power and charge USB-powered devices like iPhones, mobile phones, tablets and Bluetooth speakers.  Just connect an unprotected lithium ion battery to the B+ and B- battery inputs to make your own mobile power source. Connect multiple batteries in parallel to increase the power capacity for a longer operating time between charges. To charge the battery simply connect a 5V USB power supply to the micro-USB connector. It will charge the connected battery to 4.2V, and then shut off. The blue LEDs on the back of the module display the battery level, charging status, and also output status.   The module incorporates protection circuitry that will turn off the 5V USB output voltage when lithium-ion battery voltage drops below about 2.8V. The board includes a white LED for use as a flashlight or emergency light. Just double-press the button o