Alternator size help

[N9neMillahhh]

Cause I know that cheaper things usually aren't the best choice, but sometimes you get lucky! Anyone have experience or knowledge about the Powermax USA alternator?

[Guest]

So 250A would work, I found a 250Amp USA alternator on eBay for $230, would that be a good choice or should I get Mechman, if I get Mechman, I'll bump up to the 270Amp version.

get something that you know will work well. mechman/dc power.

why are you getting a single 380 amp fuse? the amp has dual inputs.

[N9neMillahhh]

It just says 380 amp external fuse, and I don't have enough power wire to do two runs, yet. And the wire won't be something I wanna get till later. Any ideas on that? I can get a 4 pack of 400A fuses for like $6. So I figured it wouldn't be a big deal.

[Pioneerchuck]

First off never skimp on quality when it comes to anything electrical. Especially proper wiring and fusing! As for only running 1 set of power and ground, the amp should technically still work. However, you will be starving that amp of the proper power it needs to work and you will more than likely see quite a bit of voltage drop and could possibly ruin your amp. Id say wait till you can afford to run the big boy power before you try and make it work with what you barely have.

[Emmet]

P(W) = V(V) × I(A)

power in watts is = to volts times amps

so re-arrange it to power/volts=amps

3500(watts)/(14.6Volts)= 239.73 AMP

so to answer your question, a 250 amp alternator will be sufficient, yessir

EDIT: unless you're running at 16V, which would be crazy. but if you were, just plug it into that equation, which would be : (since the site says it does 5300 @ 1 ohm on 16V) you would do: 5300/16 = 331.25amps.

Doesn't take into account amp efficiency, voltage drop or impedence rise.

You ain't gonna be seeing 14.6. Or 100% efficiency.

Maths is only good for a rough estimate.

[N9neMillahhh]

So Get the alternator first, then battery, then wire, then amp, that's the order cause I cant hook up the extra wires as is cause my battery sucks. Or should I do battery first?

[N9neMillahhh]

P(W) = V(V) × I(A)

power in watts is = to volts times amps

so re-arrange it to power/volts=amps

3500(watts)/(14.6Volts)= 239.73 AMP

so to answer your question, a 250 amp alternator will be sufficient, yessir

EDIT: unless you're running at 16V, which would be crazy. but if you were, just plug it into that equation, which would be : (since the site says it does 5300 @ 1 ohm on 16V) you would do: 5300/16 = 331.25amps.

I know what it's rated at, but I know many many people have measured theirs and I have a friend who measured his at 4319 watts with stock electrical and a single +/- run of 1/0.

[Aidan Hansen]

If I was in your shoes I'd go with a ill more than 250amp if your only going with one alt. We bass heads usually change our systems somehow I figure at least once per season. If you decide to let's say go 16v the 250amp ho alt could have a hard problem running all of that.

Also I'd suggest two runs off the ho alt because depending on the wire if its cca or ofc one wire from the alt won't be able to give you all of the power that alt can potentially give you. Since your getting a amp with dual inputs dual runs makes sense to me as well. Splitting your amps power from one 1/0 to two 1/0 into the amp would not be good for your amp. I myself am running six runs of cca from front to back(4 positive 2 negative). Alt wise two ho alts one 300 and one 350. One DC 5k for sub amp connected to the two batts in back with dual inputs.

[N9neMillahhh]

So if I got a Mechman that's 270A and get a new amp and run however many inputs on the amp I need, like if it has two sets of power inputs I'll run both sets of runs, and a new hood battery, and possibly a second battery in the trunk, would that be a good set up? Big 3 of course too. All in sky high 1/0 gauge.

[Guest]

P(W) = V(V) × I(A)

power in watts is = to volts times amps

so re-arrange it to power/volts=amps

3500(watts)/(14.6Volts)= 239.73 AMP

so to answer your question, a 250 amp alternator will be sufficient, yessir

EDIT: unless you're running at 16V, which would be crazy. but if you were, just plug it into that equation, which would be : (since the site says it does 5300 @ 1 ohm on 16V) you would do: 5300/16 = 331.25amps.

I know what it's rated at, but I know many many people have measured theirs and I have a friend who measured his at 4319 watts with stock electrical and a single +/- run of 1/0.

how do you know he wasn't clipping