What is the normal discharge current for a car?

[MacSamantha]

The normal discharge current for a car varies depending on the vehicle model: domestic cars should be below 40mA, while high-end cars should be below 80mA. To measure it, set the multimeter to the maximum current testing range. After starting the engine, connect the multimeter test leads in series between the generator line and the battery. The position of the multimeter's pointer indicates the operating current and discharge current of the car. A car battery, also known as a storage battery, is a type of battery that works by converting chemical energy into electrical energy. Specifically, it refers to a lead-acid battery, which is mainly made of lead and its oxides, with sulfuric acid solution as the electrolyte.

[LaGeorge]

I've been driving for twenty years, so I know this well. The discharge current after parking should be maintained between 20 to 50 milliamps. If it's too low, the system might still be normal, but if it's too high, say over 80 milliamps, then you're in big trouble—the battery can easily drain overnight. Once, my old car had a discharge current of 70 milliamps, and the next day it wouldn't start. Turned out the anti-theft module was stuck. Testing it yourself is simple: just use a multimeter, disconnect the negative battery cable, and measure the current in series. Don't underestimate this—regular checks can save you money on battery replacements and avoid the embarrassment of push-starting. Normal cars have small leaks like the radio clock, but don't let them accumulate.

[SanNoah]

Working at the car dealership, I often encounter issues with discharge current. The normal range is 15 to 50 milliamps, and exceeding this could indicate a module failure or a short circuit causing leakage. For example, if the air conditioning system isn't turned off, the current can easily spike above 80 milliamps. To measure it, I use a multimeter connected in series after disconnecting the battery cable, making the data clear at a glance. When customers complain about their car not starting, this is the first thing to check. High discharge can drain a new battery in just two weeks. It's recommended to check this annually, especially for cars with aftermarket audio systems, as additional installations pose a higher risk of leakage. Addressing it early can save you from needing a tow truck.

[EmmettMarie]

From a parent's perspective, this is quite important. The normal battery discharge on a car is between 15 to 50 milliamps – a very small value, but if it's significantly higher, say 60 milliamps, the car won't start the next day. Learned this the hard way when my kid forgot to turn off the trunk light after getting out, causing the discharge to spike to 90 milliamps. It was a nightmare not being able to start the car in an emergency. For daily checks, you can use a portable ammeter to prevent it from affecting your child's school commute.