Batcap, Wire Gauge vs Length question.

[rod_b 10+ year member]

I have existing 4awg in my car, about 15 ft runs for power and ground (back to the battery neg). It was running 600W (Kenwood 8104D). Planning on upgrading sub amp to 1500W and adding 400W for mids and highs. BCAE1 website says I should upgrade to 2 awg min. But if the length of wire run were 5 ft or less, 4awg would be sufficient. If I run a batcap or additional battery in back, would I still need to upgrade to thicker cable? Just wondering.

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[IDSkoT 5,000+ posts]

Dude, I have 2 AWG and I hate that ish... can't find a distro block that'll fit it... it's either 4 AWG or 0 / 0/1 AWG...

But, I'll digress back to the point:

No.

It's calculating roughly the amount of power it's pushing through that wire and how much power will be dissipated by the time it reaches the destination... adding road blocks won't make it any better.

 

[jrwalte 10+ year member]

You have no choice but to upgrade to 1/0. You could get away with running 4g from the rear bat to the amp, but you must use 1/0 from front bat to rear bat. Also do the big three upgrade if you haven't. Might as well do it in 1/0, as well. I run the same RMS as you want to and I need 1/0. I also upgraded to a 180amp alt.

 

[Louisiana_CRX 5,000+ posts]

The 4ga. should be fine as long as you run a 4ga ground with it from the front battery to the rear like Batcap recomends...In my Saleen...I'm running a Batcap 2000 in the Front and one in the back with 2 runs of 4ga...one pos and one neg...Then it goes to a DD M3 at 1ohm which is about 3000 rms on the sub...I have no dimming at all.....

 

[jrwalte 10+ year member]

That's beyond the recommended safety amperage rating for 4g, which is 125-150 amps at 15 feet. That's less than 1800RMS at battery voltage. Doesn't mean you can't run more amperage through it.

 

[IDSkoT 5,000+ posts]

The 4ga. should be fine as long as you run a 4ga ground with it from the front battery to the rear like Batcap recomends...In my Saleen...I'm running a Batcap 2000 in the Front and one in the back with 2 runs of 4ga...one pos and one neg...Then it goes to a DD M3 at 1ohm which is about 3000 rms on the sub...I have no dimming at all.....

That's because the good people at Ford put demons in your Saleen, making it work no matter what happens.

That's why I think they should've put it in Mercenaries 2 as a secret vehicle... it never blows up, never dies, and goes fast as fck.

P.S. You should PROBABLY put a fuse on that wire BTW... but, if you do that the fuse'll probably pop everytime you turn up your volume a little.

 

[headbussaboi 10+ year member]

What if you don't run a ground from the front to the rear and just ground the Batcap to the frame? I have 2 800's coming but I don't have space under the side carpet to run a 0 awg ground to the rear. Anyone tried both and see if there's any advantage?

 

[jrwalte 10+ year member]

It depends on your chassis and how resistant it is. For my '07 Corolla, I had to run a dedicated 1/0 ground. I was getting drops into the 12s, even if a heavy bass note wasn't playing, with a 180amp alternator on 1900RMS. Once I ran the dedicated ground from alternator to amp distro block, I maintain 13.9+. Only way to know is just install it and find out. If you think you're still having odd voltage drops or your amps seem to be getting hotter than they should, then consider a dedicated ground.