gravity5
+1y
If your stereo and vehicel systems draw more than your alternator can supply, you need a bigger alternator period. If you keep the smaller alternator, and add batteries, and caps that is great, but it only create more load on the alternator when it is charging those extra storage devices.
Think of it as a garden hose running at a constant flow rate, lets say 10 gallons an hour....if you have one 10 gallon bucket that it is filling, it will take on hour....correct. Great now lets say that the bucket drains at a rate of 15 gallons per hour, we have an overdraw situation. Even if the drain is intermittent, it is still too fast for the hose to keep up. So lets add more buckets, lets say another 10 gallon bucket for the fun of it. We now have a 20 gallon reserve instead of 10 gallons.....so it will last longer, but the hose still fills it up at 10 gallons per hour. It will still eventually draing completely. And the hose will have to run constantly. Thats over a 100 percent duty cycle. And as far as I know alternators are not 100 percent duty cycle devices.
All you will do by adding more reserve is make the power last longer, in the end the alternator still has to charge all of those extra devices, and will overrun itself doing it. Which in the longrun will cause premature alternator failure.