Need some advice on power fluctuations

[Teh Prof]

So, my stereo setup was in my car when I bought it, so obviously I'm not 100% sure how it was done. I'm having the problem that whenever I turn up big bass, the lights on my dashboard and OBC flicker and sometimes the stock speakers cut out (although the bass keeps thumping). Sometimes my Valentine even loses power during one of these episodes. My bet is this is not good.

My hypothesis is that the subs are drawing more power than my alternator is capable of generating while also running everything else, so I get a brown-out. What can I do to remedy this situation? Is this a sign that my alternator is going bad, or perhaps my battery?

[da_bull]

Originally Posted by M3UOND

So, my stereo setup was in my car when I bought it, so obviously I'm not 100% sure how it was done. I'm having the problem that whenever I turn up big bass, the lights on my dashboard and OBC flicker and sometimes the stock speakers cut out (although the bass keeps thumping). Sometimes my Valentine even loses power during one of these episodes. My bet is this is not good.

My hypothesis is that the subs are drawing more power than my alternator is capable of generating while also running everything else, so I get a brown-out. What can I do to remedy this situation? Is this a sign that my alternator is going bad, or perhaps my battery?

Depending on how long youve had your system, it may be time to start replacing components. First the free stuff. Clean the cable ends, have the battery load tested at a car parts shop, have them also test the alternator. I'm betting the alternator is weak, probably due to stereo, if youve got any sort of system at all. The factory alternator is really designed to keep the car running, run all the factory installed equipment, and a little reserve for some extra stuff someone might install later (maybe 10-20% extra amperage).

Lets say the alternator does 100 amps (cant remember on your car, but for arguements sake..). 30-40 assigned to the car, 20-30 for lighting, 10 for audio, 20 for reserve. A typical audio system might draw 20-40 amps. Lets say 20 amps. Everything else working properly, this would be ok. 21 amp draw and above, it starts drawing from the battery, plus your alternator is working at full tilt all the time. Eventually something has to give.

Now, add in a weak battery, dirty cabling, your system probably draws more than 20 amps, possibly weak alternator, and some "current-drawing-bass-music" you got issues now. Plus your lights are the only real noticable drop in voltage. Your radar is probably sensitive to voltage changes (like a quick drop to 10 volts or so would probably shut it off).

Remedy: sell your stereo and buy a motorcycle

Actually check about getting an upgraded alternator (rewinding yours, buying new from like Ohio Generator, an additional one), a better quality battery, and make sure all your connections are tight and clean. Any dirty cables will add more resistance, resulting in loss in voltage. Hope this helps...

[Teh Prof]

Fantastic. Thanks very much.

[325eXTATIC]

Capacitors are a great way to significantly reduce amperage draw directly from Battery/Alternator!
They are essentially short term batteries that maintain a high capacitance and allow your system to draw from the stored energy in the capacitor rather than directly from the car's available power resources.

http://www.monstercable.com/mpc/prod...&section=three

I have a half farad cap in a system I haven't yet installed in my bimmer, but when it was in my honda, it saved me from killing my alternator and kept the bass sounding tight and clear.

DaBull's recommendations are all excellent however, and if you follow through, you could easily see a 10% increase in total power available from battery/alternator, but it will take TIME AND MUCH CARE to really do it right!

Check it out!

Josh W.