The short answer is – it depends. However, in general, amplifiers do not typically drain a car battery quickly and are unlikely to be the cause of your battery running down if you’re using it regularly.

High powered amplifiers and subwoofers can draw a lot of power, especially when they are turned up to their highest levels. This can cause the alternator to be unable to recharge the battery quickly enough, leading to a dead battery.

In extreme cases, if the music is loud enough, it is possible for the battery to be completely drained in a matter of minutes.

An amplifier will draw power from the car’s battery when it is on and may draw some current when off due to the small amount of standby power required to maintain its settings. This typically amounts to around 0.1 amps which shouldn’t significantly impact the charge level of your vehicle’s main battery.

The main issue with leaving an amplifier connected for extended periods would be draining due to any accessory leads that are left connected such as bass boost or input sensitivity controls.

If these controls are adjusted while the amplifier is off then they can slowly discharge the battery. For this reason, it’s best to disconnect any accessory leads and switch the amplifier off when not in use.

Ultimately, as long as you are mindful of your electrical system and ensure that your amplifiers and other accessories are properly powered down when not in use, there should be no issues with them draining your car battery.

If you have concerns about an excessive drain on your vehicle’s battery then it’s always a good idea to get it checked out by a qualified mechanic who can identify any potential problems.


1. If possible, connect your amplifier to the car’s auxiliary power source or use a separate power supply such as a deep cycle battery or an on-board charger to power your amplifier.

2. Make sure any accessory leads are disconnected when the amplifier is off and not in use.

3. Turn the amplifier off when it’s not being used so that no standby current is drawn from the car battery.

4. Get your car checked out regularly by a qualified mechanic.

Following these tips should help to ensure that your amplifier does not excessively drain your car battery and keep it running reliably for many years to come.