Alternator Voltage: Bad or Awesome?

[BlurredVision 10+ year member]

So you never seen any issues?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.

I thought this was normal? Gotta add in all the resistance from various places

 

[ummduh 10+ year member]

Running a 12v battery into the 15range is pretty hard on it. You're definitely shortening its life.

Car electronics are generally going to live up to 16v or so. It's of course not recommended but they are able to handle it. You'd need a 16v battery to do that, though.

I personally wouldn't run past 14.8v myself. Just cuz I don't have the money to play with the big boys like that. Haha.

 

[ummduh 10+ year member]

I thought this was normal? Gotta add in all the resistance from various places

Yea its called voltage drop and 10% is usually the max drop allowed.

 

[gckless 5,000+ posts]

Running a 12v battery into the 15range is pretty hard on it. You're definitely shortening its life.
Car electronics are generally going to live up to 16v or so. It's of course not recommended but they are able to handle it. You'd need a 16v battery to do that, though.

I personally wouldn't run past 14.8v myself. Just cuz I don't have the money to play with the big boys like that. Haha.

Yeah, really at 15V I'm not too worried about my car electronics, I'm fairly certain they will survive with no issues. However, my battery is where I'm concerned. I have a Yellow Top. I have read that for standard batteries, voltage that high may cause excessive gassing and the like. Since this is a sealed deep-cycle, will I see the same problems? I'm going to shoot an email to DC Power soon, see what they have to say. Probably should have done that already.

 

[akheathen Premium Member]

yellow top won't like it at all. i've seen them swell like a bag of crayola marshmallows off stock 160a delphi. check your connections. a slight connection problem at the plug, or fuse panel will tell the ecm to tell the alt. to charge more. used to have mine run up in the 15.x range. keeping it at 14.4 nominal, only spikes 14.9 with small load recovery, haven't thrown a huge load on it and then measured with the fluke yet. i was just checking on some off-gassing i thought i smelled.

 

[mylows10 5,000+ posts]

its fine

 

[gckless 5,000+ posts]

So this is what DC Power had to say in reply to my email:

"My suggestion would be to try a different battery, optima yellow tops tend to have some charging issues with higher output alternators. There could be a chemical imbalance in the battery since they're prone to that. If you have any questions let us know.

15 volts is fine but you don't want anything higher..."

Thoughts?

 

[muskyhunter567 10+ year member]

i had 6 stinger spv70s in my car plus a red top under the hood and they were pretty cool charging up around 15-15.5v but once you got into that 16+ mark, they would start venting and hissing and stinking up the place, I would only charge the bank of batteries that high if i was at a show and wanted to get max volts right before a run, but I had the stingers in my car for over a year, and i still use three of them in my boat, they seem just fine to me, still hold a good charge and do what there are supposed to.

 

[gckless 5,000+ posts]

i had 6 stinger spv70s in my car plus a red top under the hood and they were pretty cool charging up around 15-15.5v but once you got into that 16+ mark, they would start venting and hissing and stinking up the place, I would only charge the bank of batteries that high if i was at a show and wanted to get max volts right before a run, but I had the stingers in my car for over a year, and i still use three of them in my boat, they seem just fine to me, still hold a good charge and do what there are supposed to.

That's good news. I've been watching my voltage, and it's been pretty consistent. When I first start it, when it's cold, it will run at 15.3V. Once it's warm, after driving for 10 minutes at least, it will drop down to 14.9V, and down to about 14.7 if it's warmer. I think I am just going to roll with this, and not worry too much about getting an external regulator, provided my amps will not have fits about voltage that high. I still haven't put my DC's on there, waiting on Level 3's to get in. I don't see that being a problem though.

 

[TheUnderFighter 10+ year member]

That's good news. I've been watching my voltage, and it's been pretty consistent. When I first start it, when it's cold, it will run at 15.3V. Once it's warm, after driving for 10 minutes at least, it will drop down to 14.9V, and down to about 14.7 if it's warmer. I think I am just going to roll with this, and not worry too much about getting an external regulator, provided my amps will not have fits about voltage that high. I still haven't put my DC's on there, waiting on Level 3's to get in. I don't see that being a problem though.

I think you're definitely fine, once it warms up. YellowTops aren't really the ideal car audio battery anyways. Just keep it going, if the battery goes bad, replace it with a more ideal battery. Otherwise just keep doing your thing. I don't think the amps will have any issues with that voltage either.

 

[muskyhunter567 10+ year member]

yea, you will be ok, those voltages are fine, I ran incriminators in my car so i never had to worry about to high a voltage or two low, they just worked all the time no matter what, I love those amps, but I did just get a kicker 75x4 and it shuts off around the high 15s and it gets really annoyying just listening to my bass and no vocals

 

[gckless 5,000+ posts]

Well, I just ordered a 80PRS, and noticed the manual says that the voltage limit is 15.1V. Has anyone seen issues with theirs?