Can a battery that tests good still be bad?
As long as battery voltage remains above 9.6 volts, the battery is considered “good.” But if it drops below 9.6 volts by the end of the test, the battery may be “bad,” or the battery may have to be recharged and retested if it was not fully charged prior to the test.
What causes a car battery to drain while driving?
Faulty Charging. If your charging system isn’t working properly, your car battery can drain even while you’re driving. Many cars power their lights, radio, and other systems from the alternator, which can make the battery drain worse if there’s a charging problem.
What does it mean when your battery drains overnight?
Why the Battery Drains Overnight A slow battery drain when everything is off is called a parasitic power loss. This happens when something – a glovebox light, an amplifier, any electrical component – is pulling power from the battery when it shouldn’t.
Can a bad alternator drain a car battery?
A car alternator recharges the battery and powers certain electrical systems like lights, radio, air-conditioning, and automatic windows. If your alternator has a bad diode, your battery can drain. The bad alternator diode can cause the circuit to charge even when the engine is shut off, and you end up in the morning with a car that won’t start.
Is it normal to have parasitic drain on battery?
Some parasitic drain is normal – your battery delivers enough energy to keep things, like your clock, radio presets, and security alarm operational at all times. However, if there’s an electrical problem – such as faulty wiring, poor installation, and defective fuses – parasitic drain can exceed what’s normal and deplete the battery.
Faulty Charging. If your charging system isn’t working properly, your car battery can drain even while you’re driving. Many cars power their lights, radio, and other systems from the alternator, which can make the battery drain worse if there’s a charging problem.
Why the Battery Drains Overnight A slow battery drain when everything is off is called a parasitic power loss. This happens when something – a glovebox light, an amplifier, any electrical component – is pulling power from the battery when it shouldn’t.
Some parasitic drain is normal – your battery delivers enough energy to keep things, like your clock, radio presets, and security alarm operational at all times. However, if there’s an electrical problem – such as faulty wiring, poor installation, and defective fuses – parasitic drain can exceed what’s normal and deplete the battery.
A car alternator recharges the battery and powers certain electrical systems like lights, radio, air-conditioning, and automatic windows. If your alternator has a bad diode, your battery can drain. The bad alternator diode can cause the circuit to charge even when the engine is shut off, and you end up in the morning with a car that won’t start.