Stock alternator is 145 amps, enough bang with extra batts?

[sbarber82 10+ year member]

My stock alt is 145 amps and I am going to be running a 3500 watt amp. If I add additional batts and the big 3 will I be good with the stock alt that puts out 145 amps? Or should I just upgrade to a 270amp alt plus additional batts??

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[sbarber82 10+ year member]

Anyone?

 

[Slayerx 10+ year member]

Get the bigger alt and at least one battery. You'll kill your stock batt and alt in no time running 3.5k

 

[rebelfromva 10+ year member]

Get the 270 and a 100ah batt

 

[mazdakid 5,000+ posts]

I had my old m3a on a stock alt and 2 147ah batteries and never had a problem. My alt is half your size and i ran it daily at .35 no problems at all.

 

[sbarber82 10+ year member]

I had my old m3a on a stock alt and 2 147ah batteries and never had a problem. My alt is half your size and i ran it daily at .35 no problems at all.

What is the output of that m3a? Two extra bats or one under the hood and one as a aux?

 

---------- Post added at 06:30 PM ---------- Previous post was at 06:30 PM ----------

 

Get the 270 and a 100ah batt

A extra 100ah bat or a 100h under the hood? Right now I have a 75ah batt under the hood

 

[gckless 5,000+ posts]

I had my old m3a on a stock alt and 2 147ah batteries and never had a problem. My alt is half your size and i ran it daily at .35 no problems at all.

Those are some big batteries. What was your voltage at? Because all math says this is absolutely horrible.

 

[mazdakid 5,000+ posts]

People clamp over 4k on the m3a below 1 ohm. Im not sure what my rise was though.

I had a small battery under the hood and 2 big c&d in the back.

 

[rebelfromva 10+ year member]

Extra

 

[double 07 10+ year member]

I have the stock 130a alternator in my BMW running a DC 5k wired down to 1/2 ohm and a 110 x 4 with an XS power D3100 and XP3000 and for daily it's just fine......On my longer demos I get some drop to the lower 12s but at that point the demo is over because people are grabbing ears and diving out.......LOL........You have to think about it this way are you going to be listening to that system full tilt at long lengths of time?.......For most people the answer is NO....You will have hearing issues not voltage issues.....

 

[mazdakid 5,000+ posts]

Ya i guess my daily is probably a little different than a lot of other peoples.

My ride to work is 10 minutes and same with my ride home and i didnt really drive anywhere else.

Only time i demoed really was at an old local shop and voltage didnt go under 12.

 

[UnderFire 10+ year member]

I wouldn't go over 2500 without an HO alt, and that's pushing it, having that much load on a stock alt will kill it in no time.

 

[Chrispy 10+ year member]

With proper listening habits you will be fine although like already stated the life of your alternator and stock battery may suffer.

I ran 4000 rms with a stock 140 amp alt, stock batt, Optima yellow top and Big 3 for a couple years no problem. When I did really crank it, it wasn't long before I seen 11 volts and that's when I turned it down. All about listening habits.

I would work towards a beefier electrical though.

 

[sbarber82 10+ year member]

Well I am on the fence… Half say stock alt plus extra bats is fine, half say get the ho alt and extra bats…

On a side note. 1/0 welding cable is much less expensive than "car audio" cable on ebay. Any big difference between the two performance wise??

 

[Falcons 5,000+ posts]

im telling you right now to get the bigger alt and an extra battery. if you have to ask, then you might as well be on the safe side.