Feature: OOTDTYLED Lead Acid Battery BMS Voltage Indicator. It can display battery voltage, battery power, you can also connect directly to the phone or charge 5V/9V/12V QC2.0/3.0 devices. It uses synchronous rectification system, with little heat, energy saving and environmental protection. Small size and light weight. Good workmanship and good performance. Easy to read, easy to use, durable to useSpecification:Opening size: Approx. 45*26*18mm5V/9V/12V QC2.0/3.0 USB charging (18W)The accuracy of the voltmeter is about 2%Working temperature: -10 - +65°CWouing strength: 10-80% (non-condensing)12V lead-acid voltage range: (4 series of lithium iron phosphate batteries can be used)Battery voltage is more than 10.3V+-2%, showing 10% powerBattery voltage is greater than 10.6V+-2%, showing 20% powerBattery voltage is greater than 10.8V+-2%, showing 30% powerBattery voltage is greater than 11.3V+-2%, showing 40% powerBattery voltage is greater than 11.6V+-2%, showing 50% powerBattery voltage is greater than 12.1V+-2%, showing 60% powerBattery voltage is greater than 12.3V+-2%, showing 70% powerBattery voltage is greater than 12.6V+-2%, showing 80% powerBattery voltage is greater than 12.9V+-2%, showing 90% powerBattery voltage is greater than 13.2V+-2%, showing 100% powerPackage Included:1*12V Lead-Acid Battery Capacity Indicator