Voltage Issues, Bad Alt?

[dbeez 5,000+ posts]

Thank you for posting on this.I have said the same thing to people on this forum so many times that it seams like a waste of time.

Tford on here went through this on his setup while trying to find the issue with his amp going protect his kinetik 1800 read 12.5 but would only output 400 amps and after sitting all night on a charger it was even worse battery was just shot. It was also causing his alt to charge all over the place cause it was pulling his entire electrical system down.

 

---------- Post added at 03:20 PM ---------- Previous post was at 03:19 PM ----------

 

Thank you for posting on this.I have said the same thing to people on this forum so many times that it seams like a waste of time.

Tford on here went through this on his setup while trying to find the issue with his amp going protect his kinetik 1800 read 12.5 but would only output 400 amps and after sitting all night on a charger it was even worse battery was just shot. It was also causing his alt to charge all over the place cause it was pulling his entire electrical system down.

 

[timma100 10+ year member]

Your battery bank is as strong as your weakest battery and the wetcell will pull the agm batteries down.

Do you think there are any AGM batts for ~$100 that could solve this issue?

 

[dbeez 5,000+ posts]

Well first you need to test each battery individually load test them autozpne will do it for you and then just find a good used Deka 9a34 or what ever size fits your car.

 

[pro-rabbit 5,000+ posts]

I had to load test my entire battery bank and front battery today just to make sure they were not the issue................. They were not... //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[timma100 10+ year member]

I had to load test my entire battery bank and front battery today just to make sure they were not the issue................. They were not... //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

D: Whats happening with your system buddeh??

Yeah I guess I need to have them load tested, I have a feeling its the battery up front. On short duration bass frequencies I actually get a voltage rise in the system from the alternator, sometimes up to an entire volt higher. But today just driving around the car was at 12v solid, rising with bass notes, but extended bass causes drop sens the alternator cant keep up... :|

 

[pro-rabbit 5,000+ posts]

I had a nice strong 14.7-14.8 with my setup for the season. Replaced all batteries recently and everything was great...then out of no where I can not seem to get over 13.8 now it is 13.0....and it goes down all the time and that is with no system or anything. I will be pulling the alt to check it out on it's own. I know the outcome already, but testing to make sure. The alt was already the weak link in the setup as it was having intermittent issues already.

 

[sexy 10+ year member]

I would not let autozone test anything they are morons. You can test the internal resistance of your batteries yourself better than the guys at an auto parts store using a load a dmm and some simple math. Google the subject to get the math but what I do is set a battery on my workbench hook jumper cables up to it and a car with no battery then measure that starting/resting voltage then apply car headlights for ten minutes and check voltage. Do the simple math and you have the actual internal resistance which is way better than any auto parts store test.

All batteries in a bank should be the same exact batteries purchased on the same day for best results.

Some flooded cell batteries are twice as powerful as some absorbed glass mat batteries and vice versa.

For testing alternators always make sure the test is done with an alternator that is hot from use never test a cold alternator because they may test good when they are actually bad.

 

[30Hertz 10+ year member]

Ya I'm having issues again with my electricals too. Tis' the season apparently haha. The reading I'm getting from the voltmeter and DMM from the amp fluctuate. When it's cold, everythings kosher, but spratically while driving the voltage drops from 14.8v to 13.1 and sometimes as low as 11.9 when I'm stopped. A week ago, everything was good to go, never dropped below 13.5 at a stop.

Brand new Mechman 220amp with an old *** Kinetik HC2000 battery

When I read my battery at the front with the truck on, its sitting around 14.1v when a week ago it was sitting at 14.8v.

When I look at what my alternators are getting in the bed, its sitting around 13.1 to 13.8v, when a week ago it was the same as the reading on the batt.

Gonna recheck my grounds to make everythings good on this Monday when I'm off work. Checked the belt on my alternator, its tight. If all else fails I'll load test the battery or just buy a new one to see.

//content.invisioncic.com/y282845/emoticons/pissed.gif.9f665f96bc89e98e708dabd4580bb591.gif

 

[Volvowith18psi 10+ year member]

I was reading some of Mechmans forums posts about the same kinda issue. He always recommended that his Alts were ground to the battery. Think he said use a case bolt and go right to the battery, and it solved 99% of the peoples voltage issues. Just food for thought.... Could be wrong...

 

[30Hertz 10+ year member]

I was reading some of Mechmans forums posts about the same kinda issue. He always recommended that his Alts were ground to the battery. Think he said use a case bolt and go right to the battery, and it solved 99% of the peoples voltage issues. Just food for thought.... Could be wrong...

Already did that when it was installed. 0 Guage from alt to batt..and 0 guage from alt case to batt =(

 

[30Hertz 10+ year member]

I was reading some of Mechmans forums posts about the same kinda issue. He always recommended that his Alts were ground to the battery. Think he said use a case bolt and go right to the battery, and it solved 99% of the peoples voltage issues. Just food for thought.... Could be wrong...

Already did that when it was installed. 0 Guage from alt to batt..and 0 guage from alt case to batt =(

 

[timma100 10+ year member]

I was reading some of Mechmans forums posts about the same kinda issue. He always recommended that his Alts were ground to the battery. Think he said use a case bolt and go right to the battery, and it solved 99% of the peoples voltage issues. Just food for thought.... Could be wrong...

:| Gonna have to do this, my voltage wont even get above 12.2 now, even on the cold mornings //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif (and thats with the amp off)

 

[timma100 10+ year member]

So I went to autozone, and the guy swore he could test each battery individually while they were wired together.... Part of me wants to say hes very wrong... but he is wrong right? But he did test the alternator and it was putting out 14.5 volts.. Also, doing a demo last night for my brother, the car was on, but I drained all of my batteries.. Somehow

 

[dbeez 5,000+ posts]

Dude pull the batts and have them load tested hell call a battery place if needed its a dead battery and the have to be checked individually if they check good its a grounding issue.

 

[timma100 10+ year member]

I'm taking them down to Batteries Plus today after work, if they tell me everything is fine like AZ did, im going to stab someone.. Then drive away quick.. if my car starts