How many Amps/Watts before need Alt Upgrade?

[c_hayhurst 10+ year member]

I have a 2004 Nissan Sentra with a stock alternator, which puts out 50-60 amps of power.

I also have a run of 1/0 power wire that can be hooked from the engine battery to a Stinger 300A trunk battery (battery not in the car right now). 1/0 wire is then run from the trunk battery to the sub amp.

I currently have a BXi2008D, which is rated at 1200Wx1 at 2 Ohms, to power two DC-9 equivalent 12" subs which can each handle 800W RMS.

How many watts/amps can I run on the stereo before I need to upgrade to a HO alt?

I am looking for 2000W to power my entire stereo, subs and cabin speakers combined. I would do this in my daily driver, running high volume 10-15 minutes at a time while on the freeway

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[Bradleyc2 10+ year member]

The most important thing to remember with Hifonics amps is the input voltage from your alternator.

They rate their amps on a 14.4 volt load and that is how they get the rms rating that they do.

So, if you are looking to get the rated rms from these amps, you need to make sure that your electricals are in check... BIG 3 done with HO alternator

If I'm not mistaken, the BXi2008 pulls about 140 amps.. these amps are current hungry and you almost always are going to need an HO alternator when running a HC Hifonics amps.

To answer your question, you need one now before you blow your amp up from not having enough current.

Traditionally, anything above 1000 watts is the defacto on when to upgrade your electricals.