# Your question: How quickly should car battery voltage drop?

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If you measure the voltage immediately after the end of a drive, it should be more like 13.2, and drop to 12.7 within a few minutes as the chemical reactions in the battery slow down and stop when you stop charging it.

## How much battery voltage drop is acceptable?

Voltage drop should be checked with the circuit loaded and a fully-charged battery. In best case scenarios, voltage drop on a power side or ground side to a component through all connectors, and connections should not exceed 0.1V or 100mV, however most times 0.2V or 200Mv is acceptable.

## How much should a car battery discharge overnight?

On average, a normal reading should range between 50 and 85 mA (it depends on the particular model, number of electronic modules and power devices that remain on after shutting down the engine). Your car owner manuals may give you the normal parasitic load for your car model.

## How long does it take for battery to go down?

A new and fully car battery can stay for around two weeks without needing to be recharged from a generator. This battery will fully get discharged after approximately two to three months.

## Is it normal for car battery voltage to fluctuate?

When the battery’s state of charge is low, the voltage is raised slightly to quickly put the charge back in. When the state of charge is high, the voltage is lowered slightly to prevent overcharging. If the vehicle has a voltmeter gauge, you may see the voltage move up or down. This is normal.

## Is 11.9 volts enough to start a car?

This voltage range means the battery is in good condition for starting the vehicle. If the measured reading is less than 12.2 volts, the battery’s resting voltage is weak, which means it most likely needs to be charged or replaced.

## What voltage is too low for car battery?

What voltage is too low for a car battery? A car battery is dead if its voltage is anything between 11.75 and 11.89 volts. Any reading between that range means that the battery is no longer functioning and a car owner should consider a replacement.

## What are the signs of a bad battery?

5 Unmistakable Signs Your Car Battery is Failing

• Dim headlights. If your car battery is failing, it’s not going to be able to fully power your vehicle’s electrical components – including your headlights. …
• Clicking sound when you turn the key. …
• Slow crank. …
• Needing to press on the gas pedal to start. …
• Backfiring.

## What is draining my car battery when its off?

Even while your car is off, your battery provides power to things like the clock, the radio, and the alarm system. These things shouldn’t have a major impact on your battery. What may drain a car battery when it’s off are things such as interior lights, door lights, or even bad relays.

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## How do I know when my car battery needs replacing?

How to Know When it is Time to Replace Your Car Battery

1. 1) Your Battery Struggles to Combat Seasonal Challenges. …
2. 2) Your Car Has Been Sitting For Too Long. …
3. 3) Your Vehicle Struggles When Starting. …
4. 4) Your Battery Is Older and Triggers a Dashboard Light. …
5. Alternative Starting and Battery Problems.

## Does idling a car charge the battery?

Do Car Batteries Charge While the Engine Is Idling? The answer is ‘YES’, yes the car battery does charge while the engine is idling. Again, assuming that the battery can still hold a charge. … Then the alternator is producing AC current, thereby charging the battery while your car is idling.

## How long should a 12v battery hold a charge?

A healthy 12 volt motorcycle battery should maintain a range from 9.5 – 10.5 volts under the load, for a good 30 seconds straight. If the battery begins to hold and then steadily declines, there is a problem. If the voltage drops to 0 volts, there is a problem.

## Why does my battery voltage drop?

An excessive resistance of your high amperage circuit is an overlooked problem that can cause your volts to drop in your batteries. Check to see if the cables are corroded, damaged, or loose. Resistance is usually caused by battery terminals and cables that have not been properly cleaned.

## What causes voltage drop in car?

The more connections and wiring a vehicle has, the more vulnerable the electrical system is to voltage drop. … “Voltage dropping” a circuit tells you when the circuit is too restricted to operate a component (e.g., motor, relay, light bulb) or operate it correctly. If the circuit is restricted, repair it and retest.

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