ITEM NAME:5V 12VUPS Power Diy Plate Charger and Step-Up DC DC Converter Module NBJ Descriptio n Material: PCB Color: picture color Size: 20 * 15 mm Weight: 0.01 kg 1 PCS DD05CVSB_5V 2in 1 charge-discharge boost module output 5V 2.1a charging / 2.1a discharging module Description: 2 in 1 charge and discharge (boost) module Charging voltage :DC 4.6v-8v (recommended DC 5V) Charging current: 0-1a Full charging voltage :4.2V+-2%. Led indicator: "OK" Led is fully charged or battery failure status indicator; "CR" LED is the charging status indicator Discharge current: 0-2a; Discharge static current :450uA Discharge conversion efficiency :78%-90% Output current: 0-1.2 (5 v); Operating environment temperature :-40Â °~ +85Â ° Storage temperature :-65Â ° to +125Â ° Note: This module has no lithium battery discharge protection, Application: Battery-."CR" LED is the charging status indicator. Product list :1pcs DC DC converter module. 2.1a charging / 2.1a discharging module. We'd like to settle any problem in a friendly manner. Output current: 0-1.2 (5 v);.