Will a 130A alternator run all this?

[TheUnderFighter 10+ year member]

After a yellow-top and a the big 3 in 1/0 you certainly shouldn't be experience big drops like that. If you still are, you've got another problem.

There is a way to measure alt output, we did it in auto shop, I just don't remember:\

 

[hari-bhari 10+ year member]

ok so i payed a little closer attention today on the drive home. i listen to a lot of dubstep with sustained bass notes. the voltage drops only briefly when the bass note hits, but then quickly rises back up to 13.6 while the note is being sustained (and at quite loud volume). in other words, i get voltage drops more with tight bass drum hits and kicks that are frequent, but not with long sustained bass notes. it seems like basically the alternator is taking a moment to 'catch up' with the increased demand, so the voltage drops, my lights dim, and then it quickly rises back up. so in other words, i think my amperage is sufficient?

so then would a second battery be the better solution, to provide a buffer to the jolt that the alternator is experiencing? (i may start a new thread on this topic, i.e. 'when to get a new alternator vs a second battery' because it may be a common question)

thanks!

 

[sacsking916 5,000+ posts]

So did you do big 3 in 1/0 yet? And yes the alt does take a moment to get the voltage back up. Its slight but yes there is a spurt where you drop. Shouldn't be 11s though. If your problem still happens then putting another battery is just a band aid. You'll need to upgrade your alt eventually. But can't figure it out til you upgrade your wire.

 

[hari-bhari 10+ year member]

k, i will get the wiring done first, 0awg all the way around, and then switch from the red top to yellow top and see what happens. also figure ill check the max current output on the alternator at a speciality shop, but like i said, the voltage climbs right back up to where it should, so i think the alternator is fine?

 

[hari-bhari 10+ year member]

so i got the yellow top, it rests around 12.8v, and it has helped (but not solved) my dimming issues. i just ordered about $100 worth of cadence 0 awg, 2 fuse blocks, 2 distro blocks, and terminals. hope it helps!

 

[TheUnderFighter 10+ year member]

Now we're seeing some improvements! Keep us updated when that Cadence comes in

 

[winkychevelle 10+ year member]

quick question does your car ecu control the alt, mine in my cruze does and i had the same problem. my car wouldnt charge any higher than 13.8 with the system on with drops to 13.2 but my drops to 13.2 were so slow i didnt notice but kick drum were like strobe lights. i just added more batts to stabilize the drops

 

[hari-bhari 10+ year member]

hey winky, im thinking the same thing. my voltage drops with loud sustained bass are nowhere near as bad (only down to about 13.4) as the instantaneous drops i get with tight bass hits like kick drums (which take my voltage down to the mid 12s sometimes). i guess this means that the alternator can provide enough amperage, but it just takes a few hundred milliseconds to respond to the increased demand which is why we get a temporary voltage drop. i think the larger wire will help some, but really it seems like i need a buffer in the form of an extra battery.

funny thing is i just noticed that my main 4awg line from my battery to both amps is fused only at 75A, and so i know i'm not even drawing close to maximum capacity on these amps and still getting the dimming.