Why are extra audio batteries in demand in the market?

If you look at the batteries used in the car, then you can see that these batteries are very much useful and give power to the whole car system. When you talk about the car, then you can see that music is the main thing in it. If you want to go for the music system in the car, then it consumes extra battery as well as it too put pressure on the cells. So, to release some pressure from the batteries, you can go for a new battery for your music system. Yes, when you play music in the car, it does not always mean that you run the engine of the vehicle. So, if the engine is not running, then the stored energy of batteries are used to power the music system. Why go for an extra battery? Nowadays, you can get some best and advanced music system for yourself. These systems usually use more power than the other traditional system. So, to play the music in a better way without draining the battery from your primary battery, you can always go for an extra car...