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Is 14.9-15.2v at batt too much???

  • Thread starter Thread starter bryanrevans
  • Start date Start date Jun 10, 2005

bryanrevans

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Sep 10, 2004
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Jun 10, 2005
#1
  • Jun 10, 2005
  • #1
I did 130 amp alt upgrade last month and something wasnt right.So I upgraded ground from block to sway bar bracket w/ 4 guage wire.Now I got 14.77- 15.2 v at battery.When I turn head-lights on it rises to 15 plus.
 
J

jerry beach

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Jun 10, 2005
#2
  • Jun 10, 2005
  • #2
Check voltage with the car off. If charging voltage is within 10% of battery voltage with the engine off you should be sitting pretty. I am not sure if that same rule applies to DC, but I suspect it does. I was taught the 10% rule about AC.
 

bryanrevans

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#3
  • Jun 10, 2005
  • #3
Thanks for the reply.I'll do that.I was pretty syked when I got good voltage(stock alt is 50amp)but I started to worry about too much.
 
M

mjbtv

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#4
  • Jun 10, 2005
  • #4
With engine off battery should read 12.6 volts. When charging you should read 13.8 to 14.5 volts. If you are over charging change 4 guage ground wire to 2 gauge.
 
M

mjbtv

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#5
  • Jun 10, 2005
  • #5
On second thought get the ground wire off the sway bar and put it where it was(Starter Bolt?) Make sure you have a ground strap running from the engine to your fire wall. The engine sits on rubber mounts and you will not get correct voltage flow unless hot and ground are running through the engine and grounding through the firewall is a must for your interior electronics. More questions? mjbtv@mchsi.com
 

bryanrevans

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Jun 10, 2005
#6
  • Jun 10, 2005
  • #6
Really? That ground has to be on the fire wall?I still have the stock grounding strap there.I recently added a 4 guage ground from sway bar bracket to timing cover bolt that neg side battery bolts too. Should I upgrade the fire-wall strap to 4 guage wire.Before I added 4g wire to sway bar brack.I got aprox 13v at idle.Please chime in you both make alot of sense with your input.Thanks for the help.I go on the road from Cali to Mass in a few days???????
 

HISSIN50

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#7
  • Jun 10, 2005
  • #7
I would be a little worried about 15 volts with a draw on the system. If you start blowing lights, etc, that could be bad.
 

bryanrevans

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#8
  • Jun 10, 2005
  • #8
Does that mean my internal voltage reg isnt working correctly?
 

bryanrevans

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#9
  • Jun 10, 2005
  • #9
Engine off I got 12.99 volts perhaps my tester is bad/off?
 

stang8urimport

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Jun 11, 2005
#10
  • Jun 11, 2005
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Bryan... The voltage regulator controls volts out of the alternator. If you're getting 15.2.. I'd say that is a little high. Most are preset to go to around 14.7 volts. 15.2 is on the high side. I would have it checked out... But voltage regulators are usually not covered under warranty (Autozone/Discount... those guys are just dumb and give you a free one to get you out of the store lol). I wouldn't change to a 2 gauge. That's just going to flow more current and possibly give you more volts. 12.99 isn't bad. 12.6 is good... and it will probably drop to 12.6 after a while of letting the car sit. The battery will lose a little bit of it's charge. I'd say have the alt checked out. 15.2 is high.. but not super high. Good luck, bro.
 
T

THC420

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Jun 11, 2005
#11
  • Jun 11, 2005
  • #11
i have an optima battery and my engine off voltage is 13.1. with the engine running its 14.4. to 14.7.

optimas can keep more of a charge then a regular battery.. they say when your optima shows less then 12.6 volts it needs charging.
 

jrichker

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#12
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A fully charged battery measured with the engine off will read 13.2 volts. Check to see if your voltmeter gets the 13.2 reading. If not, replace the voltmeter batteries or use another voltmeter.
 

bryanrevans

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#13
  • Jun 11, 2005
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O.K here goes.13.00v engine off.drove care arround with low speed on Taurus fan hooked up.Got 14.77 with nothing on.Headlights and low speed fan 14.2 at idle.
 

jrichker

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bryanrevans said:
O.K here goes.13.00v engine off.drove care arround with low speed on Taurus fan hooked up.Got 14.77 with nothing on.Headlights and low speed fan 14.2 at idle.
Click to expand...
I would settle for that without any reservations.
 
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