Connected subwoofer; battery died

[Hezi]

Hello y'all! Total noob here. I connected an active subwoofer in my car.

 

I connected the yellow power wire directly to the positive battery terminal; the black ground wire directly to the negative terminal; and the blue power-on wire to the blue/white remote wire behind my head unit. Since the blue/white wire was connected on both sides to the harness, I spliced into it.

 

Everything was fine for 3 days, and then the battery was DEAD.

 

Interestingly, the battery wasn't found dead after a long night, but rather after a 20-minute drive. But mainly: can it possibly be that the woofer was drawing power from the battery, despite the power-on wire?! The woofer has a power indicator light. I made sure 100% that the light goes on only when the head unit is on.

 

So was it all just a freak coincidence? Was there another electrical problem in my car that killed my battery? The battery BTW is relatively new and hasn't yet shown any symptoms whatsoever. Alternator also seems to be fine: after I jump-started my car everything has been fine since (woofer disconnected, of course), with no symptoms whatsoever.

 

Woofer is a Pioneer TS-WX130EA, head unit is an aftermarket JVC, and the car is a European Ram Promaster.

Thanks in advance!

[audiofanaticz]

As long as you wired it correctly and the power was off when the radio/vehicle is off chances are very unlikely that it killed the battery.

That amp/sub combo is 50 watts rms with a peak power rating of 160 watts (which it will never most likely never make), so it draws about 5-10 amps of current when it is used at its maximum volume and probably has a fuse rating of 7.5-10 amps. A standard halogen headlight uses about 5 amps and a pair of headlights is about 10 amps usually. For that matter your aftermarket radio has a larger amp than what you put in and draws more power!
 

So unless your having your battery die every time you turn on your headlights, and as long as the amp is hooked into the power correctly I can reassure you that the battery failed for another reason. Maybe the battery is rather old, or been abused (there are date codes of when it was manufactured usually on the battery sticker), maybe your alternator is going/went bad and is no longer able to charge the battery and the battery finally just ran out of juice, maybe a combination of the both, but not because you put in some very low power amp/sub combo that literately takes less power than any other electricidal device in your vehicle.

So going with freak coincidence along with a possible underlying issue someplace else in the electrical system would be a safe bet!

[Hezi]

9 minutes ago, audiofanaticz said:

As long as you wired it correctly and the power was off when the radio/vehicle is off chances are very unlikely that it killed the battery.

That amp/sub combo is 50 watts rms with a peak power rating of 160 watts (which it will never most likely never make), so it draws about 5-10 amps of current when it is used at its maximum volume and probably has a fuse rating of 7.5-10 amps. A standard halogen headlight uses about 5 amps and a pair of headlights is about 10 amps usually. For that matter your aftermarket radio has a larger amp than what you put in and draws more power!
 

So unless your having your battery die every time you turn on your headlights, and as long as the amp is hooked into the power correctly I can reassure you that the battery failed for another reason. Maybe the battery is rather old, or been abused (there are date codes of when it was manufactured usually on the battery sticker), maybe your alternator is going/went bad and is no longer able to charge the battery and the battery finally just ran out of juice, maybe a combination of the both, but not because you put in some very low power amp/sub combo that literately takes less power than any other electricidal device in your vehicle.

So going with freak coincidence along with a possible underlying issue someplace else in the electrical system would be a safe bet!

 

Thanks for this. Makes sense. Incidentally, while installing the amp I found three burnt 10A fuses in the car. I replaced them, and suddenly my power steering started working again, after a year of driving without it (I simply hadn't realized...). So who knows, maybe all the electrical fiddling did something. I'll have someone look at it.

 

But just to be clear: can the sub theoretically draw power when the car is off, if its light indicator is off?

[Kyblack76]

No. It shouldnt. Off is off. Just like your head unit, or the other billion things that are key"d on. 

[audiofanaticz]

Technically yes, all amps will draw some power when off but not in the sense you are thinking of. It's very little, we are talking milliamps that just keep the capacitors inside the amplifier filled up. This goes for anything electronic that has capacitors in it really, and even your radio will use some power when off to keep your presets, clock, settings intact. Again, nothing that will kill your battery.

On an amplifier that is 5000 watts rms we are talking a draw of like a half amp if not less, and having multiples of these amps wont kill your battery when the vehicle is off, so something so small like what you are using its nothing, like I said its less than equivalent to turning your lights on.