What is the normal value for car battery leakage?

[DylanRose]

The normal value for car battery leakage is 45 milliamperes. The solutions are: 1. Turn off the ignition switch, all electrical devices, and all doors; 2. Lock the car with the remote to put the vehicle into sleep mode; 3. Loosen the negative terminal screw and replace the leaking circuit. The functions of the battery are: 1. Provide a strong starting current to the starter when starting the engine; 2. Assist the generator in supplying power to electrical devices; 3. Charge the battery when the generator's terminal voltage is higher than that of the battery. The steps for replacing the battery are: 1. Remove the battery's fixing mechanism. Some batteries may have a protective casing that needs to be removed; 2. Disconnect the negative terminal of the battery. Do not disconnect the positive terminal first, as a short circuit may occur if the positive terminal touches the car body, producing sparks; 3. Remove the positive terminal of the battery. The positive terminal may have a protective device, so take care to avoid damage during removal; 4. Replace the old battery, secure the new battery, install the positive terminal, and then the negative terminal.

[LeChase]

I previously tested several cars, and the ammeter reading between 20 to 50 milliamps after turning off and locking the car is considered normal. If it exceeds 50 milliamps, the battery is prone to draining. New cars manage the dormant current well, but with more electronic modules, the leakage current can be higher. However, exceeding 80 milliamps definitely indicates a problem. Last month, a friend's car had a leakage current of 120 milliamps, and it turned out to be a short circuit in the dashcam's power cable. It's recommended to use a multimeter to measure for half an hour before taking the reading, and remember to turn off additional electrical devices like the anti-theft system. If the measured value is too high, check the fault source by pulling out the fuses one by one. Aging wiring in older cars is the most common cause of problems.

[MacLuna]

I've repaired quite a few cars with electrical leakage issues. The normal range is usually between 0.03 to 0.06 amps. German cars tend to be slightly higher, possibly up to 0.08 amps, while Japanese cars often hover around 0.04 amps. I often teach car owners a simple method to judge: if the battery cables don't feel warm after locking the car for half an hour, it's generally normal. Once, I encountered a case with 0.12 amps of leakage, which turned out to be a short circuit in an aftermarket ambient light module. When testing for electrical leakage, you need to wait for all the vehicle's electronic systems to enter sleep mode, which takes about twenty minutes. If the reading is too high, check the cigarette lighter devices first - many issues are caused by mobile phone chargers.

[VanMalachi]

A small amount of current after the vehicle is turned off is normal, as electrical components need to maintain memory functions. The manufacturer's design standard is within 30 milliamps, but in practice, up to 50 milliamps is acceptable. Last week, a neighbor complained about their battery always being dead. Using a clamp meter, we measured 70 milliamps and found that the trunk light switch was stuck. To check for yourself, disconnect the battery's negative terminal and connect a multimeter, then lock the car and wait twenty minutes for the reading. Common causes of excessive current draw include aftermarket audio systems or GPS trackers consuming power. After three years of battery use, it's important to check for current leaks more frequently.

[JasperFitz]

The normal leakage current is generally between 0.02 to 0.05 amperes. Luxury cars with more electronic systems may reach up to 0.06 amperes. The day before yesterday, I helped someone test a car with excessive leakage and found it was due to a short circuit in the blower motor resistor. It's advisable to develop the habit of turning off the air conditioning and headlights before shutting off the engine. If the battery is dead within three days, there's an 80% chance the leakage is too high. The testing method is simple: buy a multimeter for a few dozen dollars and clamp it to the negative battery cable to read the value. Remember not to open the car door during testing, as it will wake up the onboard computer. If the reading is above 80 milliamperes, repairs are necessary.