separately grounding amp and second battery? help please

[frankeyshade]

I just hooked up new system last night first time with a battery in the trunk. I have a 4 gauge power wire from under hood battery with less than a foot to a 150amp fuse then out to my trunk. Then i have a circuit breaker 150a fuse about a foot before the battery in my trunk. I grounded the amp and the rear battery to the same ground in trunk. Their is one single ground. Amp negative to bolt, and battery negative to same bolt.

My problem I'm having is when I give the system a good amount of volume the circuit breaker fuse pops in the trunk before the second battery.

I am running a Rockford bd1500cp, on a DC level 4 15" m2 dual 2 ohm. It is hooked up at 1 ohm.

Any help would be appreciated I'm sure someone knows exactly what it is. Thank you very much everyone

[slamingsuburban]

do you have another amp hooked up also and if not try replacing that breaker with a 150 fuse. also your right at the limits of what a 4gage wire will cary as far as amperage so it might be time to look into upgrading to 0 gage

[audiofanaticz]

your drawing more than 150amps of current through the circuit breaker.

Circuit breakers work slightly different than a fuse, and they trip usually right around their ratings.

unlike the circuit breaker a 150amp fuse will not blow once 150amps is passed through it, or even 165amps. The 150amp fuse may not blow until it sees 170-180amps of current for extended periods of time like 1-3 minutes (but each fuse is different, and time and amperage ratings will differ).

Either way, the RF 1500bdcp amplifier calls for fusing of 200amps, and the 150amp fuse you have is a slow blow style fuse which will handle more abuse and current over its rating unlike a circuit breaker which is meant to trip as soon as its rated current is reached.

So what you should do to fix this problem since the front 150amp fuse is not blowing is swap out the 150amp circuit breaker for a fuse, or get a 200amp circuit breaker.

The next thing I find slightly odd is that you are pulling so much current through the power wire with a rear battery which should take the grunt of the amps load since it is the path with least resistance.

I would strongly suggest grounding the amplifier directly to the rear battery, and find a good solid ground for the rear battery where you can remove any paint, rust, debris away from the ground location, and ground the wire using a nut and a bolt (no self tapping screws if you currently are). Id also check all other power and ground connections and make sure the wires are tight in the ring terminals.

My next concern is that the amp requires a 200amp fuse, and is capable of doing close to 2000watts rms @ 1ohm and upwards of 1800watts rms @ 2ohms.

This is getting to be a bit of power for 4awg wiring to handle (even if its great oversized ofc 4awg wire).

Id strongly recommend using:

1/0 wire from your front battery positive to your rear battery positive. Fuse with in 16inches of each front and rear battery with 200amp fuses.

1/0 wire from your alternator positive charging post to your front battery positive.

1/0 wire from your alternator mounting bolt to your front battery negative

1/0 wire from your rear battery negative to your chassis/frame.

4gauge positive and negative wire from your rear battery to your amplifier (keep the wires as short as possible).

The above wire will cost a little more money, but it will better suit your amplifiers need and will probably get a decent bit more power from it, as well as reduce the chance of blowing it.

[frankeyshade]

Thanks for the reply. Should I swap out the breaker and do a 200amp fuse and see how it works? My lights DO NOT DIM AT ALL, the amp is at 6 out of 11. Letting the sub break in before I go full tilt with it. I will also take the amp ground and put to battery then take the battery ground to the ground I have both rite now. Does that sound a little better?

and what is so wrong with a self tapping screw? that's currently what I have paint stripped and all.

Also the Rockford amp calls for 200amp fuse and it only has 4 gauge terminals I'm using Memphis 4g wire it's pretty solid looking. Like I said earlier when it was bumping no interior lights were dimming at all at an idol, with headlights and ac on.

Also no it is my only amp just the little bd1500cp

[frankeyshade]

Also the sub should be able to handle this amp to its full potential rite? I plan on getting it tuned by a reputable shop

Amp birthsheet is 1959 at 1 ohm

[Jhunt94]

Almost sounds to me like your clipping the heck out of the amp and trying to make it put out more power than it can which is in turn drawing too much current. Rockford does call for a 200 amp fuse but the average current draw is around 120. I have a T1500-bdcp and a T400-4 both on a 140 amp circuit breaker and I've never had a problem with it except for the first time that I ran it and had the gain up too high which caused it to pull too hard and cause the breaker to trip.

And like the others said you probably need at least 1/0 from the front to the battery and then you could go with 4 gauge from from the battery to the amp. Wouldn't hurt anything anyways.

[frankeyshade]

What do you think I should set the gain too? It's at about 7 out of 11 now. I just don't understand how it can draw to much current if their is no lights dimming at all that should be a sign rite? everything seems fine. Only thing I can think is the 2 grounds are on same ground at moment amp and battery.

[Jhunt94]

i'd try to find someone with a DD-1 or an oscilloscope to tune it.

[Jhunt94]

What do you think I should set the gain too? It's at about 7 out of 11 now. I just don't understand how it can draw to much current if their is no lights dimming at all that should be a sign rite? everything seems fine. Only thing I can think is the 2 grounds are on same ground at moment amp and battery.

not necessarily. You could have the biggest battery bank in the world, but if you have the gain on the amp set way too high then the amp will be drawing more current than it should and since you have a second battery then it might not be cause a big enough voltage drop for the lights to dim. The gain adjustment isn't a volume knob and shouldn't be treated as such. And your problem might not be this, but I'm just speaking from experience and stuff that has happened to me.

[frankeyshade]

Sorry I'm not talking about bass boost I'm talking about the level. Bass boost is at zero if that's what your thinking.