"Personally I try and build around 2kw or less for subs and 1500w or less for highs. That's around 300amps of current draw. Anything more and electrical upgrades get extremely costly."
If I get a: Extra Battery, and 250 Amp Alternator, will there be any potential further risk of extremely costly repairs?
My dash board lights started glitching and shutting off recently.
Also would you run an extra Battery for under 2K RMS or Peak?
It depends. Agm batts don't discharge and recharge very fast so they cannot support large amperage draws like lithium. It used to be 100ah per 1000w over the base 1000w.
A 250amp alt can support 3kw with a simple secondary battery. But fact of the matter is you should not let voltage drop below 12.5v. like ever
Staying above 13v is much more preferably.
And you have to consider the cost
High output alt $4-500
100ah agm $100-200
1/0 wire $3-5/ft
With just 2 25ft runs of 1/0 you are looking at $750 granted I wouldn't run a second run of 1/0 till I broke 4kw and at that point you would need more battery.
250amp alt - 50amp to run the vehicle(estimate but is usually close) = 200amp
200amp+100amp secondary batt+45amp primary batt= 345amp of leftover amperage
345amp×12.5v(agms rest at 12.5v some a little higher)=4312w
4312w×75% amp efficiency=3234w real world capability
That efficiency should be possible with most class d amps running 1ohm but 70% would still be 3018w
This is also worst case scenario since music is dynamic and you aren't drawing 345amps at all time. You also should be at a higher voltage so you have potential for
This is why agm vs lithium is so significant
Lithium drops .1v per cell and just holds until depleted so from 15.8v down to 15.2v where as agms just keep dropping as they drain. It's weird but that's just how agm vs lithium is.
Agm is draining like driving down a levee into the river
Lithium is like driving off the bridge. Both get to the river bottom but lithium just doesn't sink as fast. And this give the alt more time to top the lithium off during low drain parts of music.
Lithium is expensive but is significantly stronger. But it has a learning curve and requires research and a willingness to learn.