Alternator Voltage: Bad or Awesome?

[gckless 5,000+ posts]

So I got my DC Power 270XP about a week ago, and installed it last Tuesday. The 1/0AWG wire I had in there as part of the big 3 wasn't long enough, so I left it off. At that time, I was getting 14.8~14.9V at idle. Just installed my 1/0AWG positive lead from alt to battery, and now I'm getting 15.4V at idle. Is voltage sitting that high bad news, or is this just what a good HO alternator should be doing, and I should be really glad?

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[goingdef 10+ year member]

well that seems a little high but I don't know that one volt over normal would hurt anything, heck just do what I would do and use the stereo to pull it down there now you have an excuse to rock full tilt all the time!

 

[rebelfromva 10+ year member]

More watts at higher voltage! Did it stay that high or when you first start the car?

 

[ssteele18 10+ year member]

It would make sense that you're alt is seeing less resistance with the 1/0 thus bumping it up .5... It was already running 14.9 on factory wire right?

 

[CAT MAN 5,000+ posts]

i wouldnd go above 15 if i were you. im setting my external reg to 14.8 and leaving it

 

[bumppinKota]

in my experience with alternators when first replaced they run higher voltage for a while but i have never used a high out put one so i can not say for sure with that one. alternators also put out higher volts usually when the battery goes bad or is going bad as well. but 15.4 may just be cause its new. again tho no experience with h.o. alts

 

[Kangaroux 5,000+ posts]

I suggest setting your voltage to mid 14's, around 14.5-14.6. You won't notice any difference in output from a few tenths in your voltage, and your batteries won't hate you for it either

 

[gckless 5,000+ posts]

More watts at higher voltage! Did it stay that high or when you first start the car?

This was when I first started it, and let it idle for about 5-10 minutes. Haven't drove it yet.

It would make sense that you're alt is seeing less resistance with the 1/0 thus bumping it up .5... It was already running 14.9 on factory wire right?

Yeah it was.

i wouldnd go above 15 if i were you. im setting my external reg to 14.8 and leaving it

I suggest setting your voltage to mid 14's, around 14.5-14.6. You won't notice any difference in output from a few tenths in your voltage, and your batteries won't hate you for it either

That's what I was thinking, but I don't have an external regulator. I want to try to get away with not buying an external regulator if possible. I also don't have any real draw on my system now, pulled my 2.0k out for a new install, and only have a small 50.4 for the front/rear speakers in there now.

 

[muskyhunter567 10+ year member]

i was about where you are now with my old set up, i was told that 15-15.5v can be into the realm of damaging factory car components and carputers and what not, but mine would run high 15s in the winter when i would start it up and then dip back into low 15s high 14s, i was super stoked to have voltage that high, the way i see it, the higher it is without damaging things the farther it has to go down to damage more things!!!

 

[thundercat 10+ year member]

My mla mod runs 15.3 -15.7 @ idle & have had no isdues daily for over a yr now

 

[gckless 5,000+ posts]

i was about where you are now with my old set up, i was told that 15-15.5v can be into the realm of damaging factory car components and carputers and what not, but mine would run high 15s in the winter when i would start it up and then dip back into low 15s high 14s, i was super stoked to have voltage that high, the way i see it, the higher it is without damaging things the farther it has to go down to damage more things!!!

So you never seen any issues?

I just drove it up to the store, about 5 minutes away. I have a underhood voltage meter, as well as another one in my dash that has wires ran to the trunk to monitor voltage from any point there, currently on my 4 channel amp. My trunk is about .1~.2V less than my underhood meter, indicating either improperly set meters or a less than optimal ground. I'm not too concerned witht that right now though. On the dash voltage meter, I am now seeing 14.8~15V at idle. That number doesn't move much, if at all, when at RPM's (anything at 2000 or above). I'm thinking this won't be a problem, and is actually very good.

I don't know why I seen 15.5V before though. I'm thinking it's because it was cool. When I first started it up before I ran to the store I seen 15.3V under the hood. When I got back home and checked it was sitting at 15.0V under the hood.

Anyone else see this with DC Power XP's?

 

[gckless 5,000+ posts]

My mla mod runs 15.3 -15.7 @ idle & have had no isdues daily for over a yr now

That's good to hear. In what vehicle? What was the stock alternator?

 

[thundercat 10+ year member]

An 2001 explorer, and a db electrial 240amp alt

 

[mlstrass 5,000+ posts]

cold alt and fully charged batts will read higher at start up. I get 15.3 out of my 270xp when batts are fully charged, but that will settle to 14.9 after playing stereo for a few minutes at low volume.

 

[gckless 5,000+ posts]

cold alt and fully charged batts will read higher at start up. I get 15.3 out of my 270xp when batts are fully charged, but that will settle to 14.9 after playing stereo for a few minutes at low volume.

Yeah, that's what I'm seeing now. I have been getting 15.3~15.5V at startup, and 14.9~15.1V at idle when it's warm. I don't think this should be a huge problem, even though I don't necessarily like it that high. Basically, I love it, but I'm worried too. If that makes any sense....