Dual USB 5V 2.1A 1A Mobile Power Bank Charger PCB Board Boost Step Up Module With LED Display Board for 18650 Battery Phone DIY

Designed for 18650 battery DIY power bank: The battery of the 18650 battery must be flat, and the length is 65MM. The pointed battery cannot be used. If you are using old batteries, different capacities, different brands are not available, the assembled battery is guaranteed to be at least 3.5V per voltage. If the voltage is too low, it will not be charged. (It also support lithium battery, mobile phone battery and tablet battery). Supported connection methods: It is possible to connect only one lithium battery or multiple lithium batteries in parallel. The capacity of connected battery is no more than 200,000 mAh, As long as the battery with a voltage of 3.0-4.2V can be used. Charge indication of this power bank pcb board: The word "IN" will be shown in the display; Output indication: Long press the LED button after turning on the load, Start output, The word "OUT" and the current and voltage of 5V 1.0A or 5V 2.1A will be displayed in the display. This is a mobile powerbank module with Protection Function: The protection circuit of the boosted lithium battery has been integrated, prevent over-discharge, over-charge, overload short circuit protection, over current protection, and over temperature protection. Note: The positive pole of the battery is connected to B+ and the negative pole is connected to B-, do not reverse it. If it is reversed, it will burn out!!!! Why can't continue charging when charging capacity is 99%? You just assembled the battery, why the display percentage is not accurate, the battery power is only 50%, but it shows 80% after assembly?--Whether you are using a new battery or an old one all need to be discharged before use(charge your mobile phone), then turn it off charge it once gain. If it still cannot be solved, it is caused by large internal resistance and inconsistent capacity. Package included: 1X Battery Charger Board