How to measure 12v battery with multimeter
How to measure the battery power with a multimeter?
Use a multimeter to connect the ammeter in series between the battery and the negative cable according to the connection method in the figure below. turn left | turn right
Before connecting the meters in series, you need to set up the meters first, first of all, select the type. Turn the knob to the DC current position. The mark is a horizontal line on the top, three dots in the middle, and a capital A on the bottom. This meter does not need to select the range, ordinary multimeter should choose flow 10A, or DC 20A. Then select the position of the test lead, the black test lead is always at the COM position, and the red test lead selects DC 10A or DC 20A.
Finally, connect it to the battery, first turn off the key and all electrical appliances on the car, and remotely lock it. Connect the red test lead to the battery cable and fix it firmly. Loosen the negative cable screw, connect the black test lead to the battery terminal, and then slowly remove the negative cable. Be sure to disconnect the cable after connecting the test leads, and the test leads cannot be reversed, otherwise the reading will be negative.
Wait for the various modules of the vehicle to go to sleep, and read out the accurate static discharge amount. Generally, it is normal if it is within 50mA. The measurement in the above picture is 335mA, and the battery of this car is 65Ah. Calculate 65÷0.335=194.029851, 194÷24=8.08333333, that is to say, the battery will be completely drained in 8 days. The vehicle will not start in less than 4 days.
How does a digital multimeter measure a 12v battery?
It can be tested by directly touching the two electrodes of the battery with the positive and negative test leads of the multimeter. The specific operation is as follows:
1. The multimeter has two test leads, the colors are red and black. The red test lead is inserted into the V/Ω hole, and the black test lead is inserted into the VCOM vacant position.
2. Adjust the gear of the multimeter to the [DC] voltage range, 20V.
3. Press the switch button of the multimeter to display numbers such as 0.000 (depending on the accuracy, the number of decimal places is different).
4. Use the two pen tips of the multimeter to touch the two electrodes of the battery respectively, and the multimeter will display the value. This value is the battery voltage. 5. If the displayed value is negative, just exchange the two test leads of the multimeter. Finally, please pay attention not to short-circuit the two electrodes of the battery, otherwise the battery may explode.
Put the multimeter in the DC voltage range of 50V, insert the red test lead into the "+" jack, and the black test lead into the COM jack, touch the positive pole of the battery with the red test lead, touch the negative pole of the battery with the black test lead, and then read directly from the dial.
