Highlight LED digital tube display， light and easy to see inside the carSimple to use:Directly inserted into the car cigarette mouth， then test battery voltage detection， convenient and practical.operating parameter:range:7-20 v dc voltage is 12 v car availableDisplay Accuracy :0.01Voperating voltage:7V-20VMeasure the current sampling frequency:3 times/SECFeatures:Powered by car cigarette lighter charger (DC 12~24 V)When engine running (do not drive)，the LED dispaly:Between 13.5 TO 14.5 (12V CAR)Between 26.0 TO 28.0 (24V CAR)With the engine off， and nothing turned on，the LED dispaly:Greater than 12.0 (12V CAR) OR 24.0 (24V CAR)(for reference only)Measuring range : DC 8V-30V��%1.2Installation: insert the jack of the product into a cigar socketLED Display Cigarette Lighter Electric Voltage Meter For AutoCar Battery Car battery voltage displayWith high brightness of LED(light-emitting diode) there is no difficulity in seeing the display.With high brightness of LED there is no difficulty in seeing the displayThis digital gauge displays the voltage of batteries in the car.Installment:Clean the cigar socket.Insert the jack of the product into a cigar socket.Specifications:Net weight:22gPackage weight:33gPacking content: 1 x Electric Voltage Meterspecial suggestion:1.12 V lead-acid battery normal voltage range is 10.5 V to 14.8 V2.Different brand battery depending on different acid concentration and temperature， slightly floating up and down.3.when discharge， Voltage decrease with time.Discharge is lower than 10.5 V for discharge，Cause irreversible damage to the battery，Should be timely charge， reduce or off load device.To start with battery， should check whether the generator to the battery charging circuit is normal.4.When charging， voltage increased over time.Higher than 14.8 V， the battery overcharge the same injury.Check the charging circuit and generator is normal.5.Key check whether the battery is lack of water， should be timely added distilled water (acid)， in order to avoid the battery overcharge fever until discarded!The significance of voltage values: When the motor power， is the battery voltage， the normal value of 12.2 to 12.2. Will note below 11.6 close on-board electrical and immediately started the engine charge as soon as possible. Connected to a professional battery testing instrument testing， capacitance value less than 10 May not start After the car start，is the generator voltage，Normal value of 13.4 to 13.4， lower than 13.4 cannot be recharging the battery. Check the generator belt and abnormal of automotive electrical load，Above 14.8 is electricity will damage the battery and the car electrical appliances，Check the generator voltage regulator