4.6L alternator charging voltage?

[simplicityinsound]

hey guys,

so i noticed something rather bizarre today while testing this car.

2012 genesis sedan 4.6.

the car has been in my garage being worked on, only stated and idled a few minutes a day to keep the battery topped off.

today i acutally went and took it for a drive around the block.

so just to test voltage, i took out my multimeter and noticed that while idling, the car is only charging at 13.2-13.3 volts.

this is lower than any other car i have tested.

so i let it idle bit longer and eventually, when i checked on it again in about 20 mins, it was charging at normal voltage of 13.9-14.0 (this with the stereo system idling so drawing a lil voltage).

so i wanna confirm what other people are seeing? i assume this is a computer controlled alternator, but what i dont quite understand is why on a somewhat depleted battery, it will only charge 13.2-13.3 for the first oh...15 mins or so (5 mins of idling 10 minute drive) and then bump up to normal voltage later. most cars i have measured, even with computer controlled alternators, seem to charge at 13.8-9 even on start on, regardless.

so i wanna see what you guys have to say and determine if its something wrong with this brand new aftermarket battery (i have had that happen) or if this is something totally normal with this car?

thanks!

Bing

 

[Philth]

Im not sure if the Genesis has it, but 2011 Sonata had this rather off alternator management and only charged the battery when a load was placed on it. If I was cruising down the highway during the day time, my voltage would drop to 12.6 - 12.8 and was normal. Under loads, voltage would go up to 14s.

 

[simplicityinsound]

yeah tahts what this sounds like. okay, just checking, if anyone has a voltimer handy and dont mind taking a minute to try it out on start up under the hood, it will be much appreciated

i would imagine that if the sonata has it, a car like the genesis MUST have it. i wonder if there is a way to disable it...cause when holding only 13.0-13.1 volts on idle listening, the amps in this car wont be producing quite as much power

b

 

[Philth]

My radar detector has a volt meter. Give me a sec and I'll go check.

 

[simplicityinsound]

thanks bud! i wonder if the system is in there...if its just a voltage regulator that i can remove, or a computer controlled clutch that needs to be overridden. hmmm

 

[QCTLG]

if anyone has a voltimer handy and dont mind taking a minute to try it out on start up under the hood, it will be much appreciated

I remember when I was installing my amp and sub (Orion D1200 and a SSA Icon 12" connected at 1ohm), my reading was 14.55v with no music playing and when blasting a heavy bass song it would drop to around 14.34v. This is on a 2009 V8.
This of course with the engine running.

Can't wait to see your project finished!

Regards,

 

[simplicityinsound]

I remember when I was installing my amp and sub (Orion D1200 and a SSA Icon 12" connected at 1ohm), my reading was 14.55v with no music playing and when blasting a heavy bass song it would drop to around 14.34v. This is on a 2009 V8.
This of course with the engine running.

Can't wait to see your project finished!

Regards,

hmmm intersting....

the way this car is behaving, it doesnt sound like a bad battery...anyone have a 2012?

 

[Philth]

Bing, sorry dude I totally forgot to reply with the results.

The car averaged 14.4v with car running at idle with or without lights on. Only when I turned climate control to high would it dip into the high to mid 13s.

When the engine was above idle, it was always mid 14s.

Doesn't seem to behave the same way as my 2011 Sonata did. Hope this helps.

 

[simplicityinsound]

thanks! that helps!

 

[simplicityinsound]

so i think i got this figured out...

its basically i think the much higher capacity battery that i put in, as it drained slowly over the course of the two months while i had the car, when finally started, presented a heavy load to the alternator as its not used to seeing this big ole AGM battery...so i took the car for 2 x 10 minute drives the other day...and now, the voltage pretty much jumps to 14.x right away.

thanks for all your help guys!

Bing

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[P-bar]

Alternators need to spin up a bit before they really start producing energy. Through the years they have bumped up the voltage of the charging system to accommodate all the electric power devices. There are also sensors on the battery to monitor temp and shut down the charging system so you won't frag your trunk.

 

[simplicityinsound]

Alternators need to spin up a bit before they really start producing energy. Through the years they have bumped up the voltage of the charging system to accommodate all the electric power devices. There are also sensors on the battery to monitor temp and shut down the charging system so you won't frag your trunk.

hmmm almost every car i have tested have always registered 14.x volts almost with in a second of starting the car. unless the battery is drained and/or a lot of components are turned on.

this car measures fine now, i think it was just a depleted battery

b

 

[maxmar04]

my 3.8 sits at 14.1-14.2 during idle. Not to jack your thread but can anyone tell me who my voltage SOMETIME drops when i accelerate? its the weirdest thing, especially because it only happens once in a while.

 

[simplicityinsound]

my 3.8 sits at 14.1-14.2 during idle. Not to jack your thread but can anyone tell me who my voltage SOMETIME drops when i accelerate? its the weirdest thing, especially because it only happens once in a while.

on modern cars, a wide variety of things can cause voltage to drop, battery status, what your car decides, what systems are on and how much current they are pulling, all matters.

if you mean a drop to say 13.7 to 14.0 its not really to be concerned about...if it really drops to below a low 13.x then thats a bit odd...but may not indicate a problem. could literally be the circuit that your voltmeter is connected to seeing a drop, not the entire car. i can only measure it at the battery or the front charging port under the hood so i cant really say for sure while accelerating.

b

 

[maxmar04]

on modern cars, a wide variety of things can cause voltage to drop, battery status, what your car decides, what systems are on and how much current they are pulling, all matters.

if you mean a drop to say 13.7 to 14.0 its not really to be concerned about...if it really drops to below a low 13.x then thats a bit odd...but may not indicate a problem. could literally be the circuit that your voltmeter is connected to seeing a drop, not the entire car. i can only measure it at the battery or the front charging port under the hood so i cant really say for sure while accelerating.

b

i have a volt meter installed next to my ESC off button and it is wired to my battery. sometimes it drops as low as 12.6 on acceleration :/