Removing the battery with the car running is a bad idea. Rather than re-writing something which exists on the interwebz, I pulled this from Troubleshooters.com under the section called Automotive Troubleshooting: Your battery does more than just provide electricity. It also shorts AC spikes and transients to ground.
Can you change a car battery with the car running?
No! You cannot remove a battery from a car while the engine is running!
Can you drain a car battery with the engine running?
Avoid Draining the Battery
As we mentioned, the battery charges when the engine is running. Conversely, it won’t charge when the engine is off! … Sitting in a parked car with the engine off, headlights on, while charging multiple devices, is a recipe for draining your batteries.
Does leaving a car running charge the battery?
“Starting the engine draws 100 to 130 amps, and idling the car for 15 minutes might put back three or four amps,” Brown-Harrison says. “If you’re idling only for 15 to 20 minutes, the battery never truly gets recharged. So each time you start and leave it to idle, the charge will get lower and lower and lower.”
Should I let my car run after replacing battery?
If it starts, let it idle for at least 20 minutes, or go on a five-mile drive so the battery can recharge. If it still won’t start, repeat the process.
How long will a car battery last if disconnected?
When the battery is removed, it can stay for six weeks to 6 months. However, you need to keep recharging the battery over time. Ideally, the battery should be recharged every 12 weeks when the battery is disconnected.
Can you test an alternator with the car off?
Simply check the voltage of your battery by touching the multimeter prongs to the terminals with the car shut off. Take note of that number; it should be somewhere in the 12-to-13-volt range, according to Hines. Then, start the car and check the voltage at the battery again while the vehicle is running.
Why does my car battery keep dying overnight?
Some of the most common reasons for a car battery to die repeatedly include loose or corroded battery connections, persistent electrical drains, charging problems, constantly demanding more power than the alternator can provide, and even extreme weather.
How long can I leave my car running while parked?
Idling your car for 30 seconds to a minute is acceptable, and it will not cause any harm to your vehicle. With advanced technology, even if you let your car idle for a slight longer duration, it will not damage it.
What are the signs of a bad alternator?
7 Signs of a Failing Alternator
- Dim or Overly Bright Lights. …
- Dead Battery. …
- Slow or Malfunctioning Accessories. …
- Trouble Starting or Frequent Stalling. …
- Growling or Whining Noises. …
- Smell of Burning Rubber or Wires. …
- Battery Warning Light on Dash.
Does revving the engine charge the battery faster?
But when your engine turns faster, the engine’s alternator also turns faster. … That way, all of the alternator’s power can be directed to recharging the battery. Once the car starts, you can rev it up to charge the battery faster, but the best way to do that is to just drive it.
How long should you idle a car to charge the battery?
If you find any of these cars start easily (the starter spins quickly), battery status is likely quite good, and a short drive or idling for 10 to 15 minutes may be adequate to keep the battery full, if done once every two weeks. If slower cranking is noted, a half hour drive once a week should do the trick.
How do you keep a car battery from dying when not in use?
5 Ways to Help Avoid a Dead Car Battery During the Summer
- Keep it cool. Since heat drains a car’s battery, parking it in a cool or shaded spot can buy your battery extra time. …
- Increase your driving time. …
- Cut down on car battery drain. …
- Keep it clean. …
- Get a car battery charger.
How do I reset my car after replacing the battery?
Switch off your vehicle and unplug all fuses once it has completely warmed up, then detach the battery to cut power. All of the old data should be reset after a few minutes, so reconnect the fuses and restart your engine.