Stepdown converter questions.....lots of them

[Steve390Gold]

Ok I want to put a BANGING system in my RXV. (My 4Runner had over 9kW rms power) So the foundation has to be a lot of 12v dc current. Thus far the largest 48 to 12v converter i can find is a 60amp unit.

Do they make anything bigger? I suppose i could parallel several 30A stepdown buck converters into a single, large 12v battery to act as a buffer and supply the amplifiers off of that battery? This would be a rough analog of a 90 amp alternator supplying the main battery in one's car correct?

Given the simplicity and relative good efficiency (85+%) of buck converters, has anyone constructed their own?

[cgtech]

This is a lot of "If's"...

If your DC Converter is "rated" to charge a battery, or be connected to a battery on it's output side (I have never seen one that "officially" supports that).

If there will be a problem trying to parallel several together, issues such as perfectly matched output voltages amongst all of them to be sure load is balanced among them. That's the first issue that comes to my mind.

[Mooncarter]

Sounds like a lot of power draw. Will a separate 12 volt battery do it?

[cgtech]

Two problems with that.

Amps like he is talking about run on 0 gauge and larger wires, they will drag the battery down and turn off quickly.

And amp power ratings are done at 13.4v (I think that's the number), not "12v battery at rest voltage", and their efficiency and power are lower at lower voltage.

On YouTube there is a channel called BigDWiz that has tons of cool car audio amp stuff thats fun to see.

[Mooncarter]

110v inverter? With different setup?

[Steve390Gold]

Originally Posted by Mooncarter

Sounds like a lot of power draw. Will a separate 12 volt battery do it?

In theory sure, however to accomplish this in reality would require an array of batteries. At a minimum of 4 group 31s and even those would deplete quickly.

Originally Posted by Mooncarter

110v inverter? With different setup?

Im not sure i follow?

[Steve390Gold]

Originally Posted by cgtech

Two problems with that.

Amps like he is talking about run on 0 gauge and larger wires, they will drag the battery down and turn off quickly.

And amp power ratings are done at 13.4v (I think that's the number), not "12v battery at rest voltage", and their efficiency and power are lower at lower voltage.

On YouTube there is a channel called BigDWiz that has tons of cool car audio amp stuff thats fun to see.

Yuppers, 1/0ga everywhere and speaker leads were 8ga. In dB drag racing i used to compete in street C. No power limits but you were limited on number of conductors entering the box (8 in street c), and type and size of subs used. Engine off and only 1 additional battery of equal size to OEM. With 4 Zapco 9.0's running off of 2 group 34 blue tops, the system voltage would drop from 13.0-12.9 to about 9.2v during the 3 second burp!! Even under those brutal conditions each of the 4 amps was generating about 15 to 16 amps and between 110-118 vac @ 43hz so roughly just under 1800 watts. The amps are rated to produce 2200w rms each so i was quite impressed with their output into the reactive load.

These amps powered 2 DD9915's, then i tried 4 kicker L7 12's, which was hilarious as they could not handle the power at all at full volume. And even the DDs would get stressed after about 15 seconds....lol Never did blow any subs.

I miss that truck...lol

[Steve390Gold]

Originally Posted by cgtech

This is a lot of "If's"...

If your DC Converter is "rated" to charge a battery, or be connected to a battery on it's output side (I have never seen one that "officially" supports that).

If there will be a problem trying to parallel several together, issues such as perfectly matched output voltages amongst all of them to be sure load is balanced among them. That's the first issue that comes to my mind.

Oh yeah that is a biggie....do any output converters on the market have a gain so i could voltage match them down to the weakest one with a DMM? Im guessing not?

[cgtech]

None that I know of.