Not sure if I have a problem or not.

[TurdFergueson2 5,000+ posts]

I usually monitor my voltage off my 800PRS because my car does not have a meter that shows you your battery voltage. If it does I never saw it. Anyways, I've noticed that my voltage appears mid low 13s all the time. Originally I had a red top up front and an HC800 in the rear, 250 amp alt. Off the radio the voltage was 14.2-4 driving, maybe 13.7 at the lowest. Winter came, and it froze both my batteries I guess. I got the red top changed out in the front to a brand new one and the rear is a new Yellow top. Before that though, I noticed my voltage was staying low mid 13s constantly. So I just dealt with that through the winter as I have another car to drive without those issues.

It got a little warmer here so I started trying to see what's going on. I changed the belt before I changed the batteries. Still the same. I tested everything with a DMM yesterday and today. I put the yellow top up front and a SPV70 in the rear. 13.7 then dips to low 13s. Batteries were at 12.45 with nothing on. with the car running they go up to 13.5 the alternator running showed a voltage of 14.45 and it was driven like 30 minutes prior. I can play my system as loud as I want and the voltage may dip to 12.9 and go back up. I saw what I wouldn't even consider bad dimming, but again it was as loud as I will ever play it. So I don't want to ignore it and be stranded one day. I just want to make sure that everything is ok. I have pretty much changed everything but the alt. I have my old one still, but it's a pain to put the new one back on. So right now I can only say that the issue could be in the wires or the alt. I got no issue rewiring the car if that fixes the issue. I just don't know if the issue is an issue.

Cliffs: Old electrical system always read 14.2+ until winter. Won't go in the 14s despite new batteries.

No changes to the equipment (XA4000, AQ2200D, HDC3-15, all wiring and big 3 done in 1/0 Kicker wire)

Any help with this would be appreciated.

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[loopkiller 10+ year member]

If your batteries are resting below 12.8V they are not getting fully charged. If your alt (without audio load) does not charge above 13.8V it is probably dead. Best getting the alt load tested ASAP before you burn through 2 more batteries.

 

[TurdFergueson2 5,000+ posts]

I did that like a week and a half ago at Advance auto parts. They connected to my battery and put some clamp type meter on that connection and the guy told me that the alt was charging at 13.8. I put my DMM on just the alt the other day and it said 14.45. I looked at that fuse on my big 3, and it has not popped. I redid my battery to frame, and it still did not help. That was my next move to just redo my big 3 and see what happens. What's confusing is that everything worked fine from mid August to around New Years. No changes to anything before the problems.

Thanks for the reply.

 

[loopkiller 10+ year member]

My only other comments are that if your alt charge is never higher than 13.8V, something is wrong with the alt. If your batteries are resting below 12.8V (open circuit test) then they are not staying fully charged.

Here is what I would do. Disconnect the amps for a few days. You can simply pull the inline fuses out. Drive this way for a few days to see if the alt will recharge the batteries. If nothing changes, you for sure have a bad alt. If the batteries do recharge back to full, then you know that the alt is just too small for your system and you will either have to moderate your volume levels or charge the batteries while the car is parked.

 

[TurdFergueson2 5,000+ posts]

I can try that, but a 250 amp Mechman on maybe 2600 watts of power and 2 new batteries should be more than enough. I had a smaller battery in the back and it was fine. Anything is worth a shot at this point.

I was also considering putting my old alt back on and seeing what I get. It's only 130 amp though.

 

[loopkiller 10+ year member]

I can try that, but a 250 amp Mechman on maybe 2600 watts of power and 2 new batteries should be more than enough. I had a smaller battery in the back and it was fine. Anything is worth a shot at this point. I was also considering putting my old alt back on and seeing what I get. It's only 130 amp though.

At this point, you for sure have an issue. You can assume that the Mechman alt is good, but that does not make the problem go away. Either start swapping out parts to eliminate them from the equation, or get things tested individually.

 

[iamamp3pimp 5,000+ posts]

I did that like a week and a half ago at Advance auto parts. They connected to my battery and put some clamp type meter on that connection and the guy told me that the alt was charging at 13.8. I put my DMM on just the alt the other day and it said 14.45. I looked at that fuse on my big 3, and it has not popped. I redid my battery to frame, and it still did not help. That was my next move to just redo my big 3 and see what happens. What's confusing is that everything worked fine from mid August to around New Years. No changes to anything before the problems.
Thanks for the reply.

ever think of putting the batts on a trickle charger>

 

[iamamp3pimp 5,000+ posts]

i had mine sitting on a 2 amp charge (for 7 batteries) for 2 days, and they sat at 13.1 at full tilt for the longest time.

these are wal mart batteries btw...

 

[TurdFergueson2 5,000+ posts]

ever think of putting the batts on a trickle charger>

I did that overnight on both before I put them in last week. So at this point only thing left is the alt and the wiring. I was even thinking my HU was a full volt off until the batteries while the car is running running were pretty much the same on the HU as the DMM. If anybody cares, I will update this weekend.

 

[iamamp3pimp 5,000+ posts]

my alt was charging @ 14.4-7 after i charged the batteries...before that it was 12.9 at times....,

 

[loopkiller 10+ year member]

my alt was charging @ 14.4-7 after i charged the batteries...before that it was 12.9 at times....,

That would make sense if the batteries were low and were drawing an abundance of current to charge. If you had 7 drained batteries, they were probably pulling 10A per battery, 70A total. If you had a stock alt, that would be pulling the voltage way down.

Now if you had just 2 batteries that were low and charging, it would only be a draw of 20A, which is less likely to draw down the voltage as much.

So in TF2's case, his were charged before installing them, which would discount the low voltage being caused by undercharged batteries. His issue must be either a defective alt or a loose connection somewhere.

 

[TurdFergueson2 5,000+ posts]

That would make sense if the batteries were low and were drawing an abundance of current to charge. If you had 7 drained batteries, they were probably pulling 10A per battery, 70A total. If you had a stock alt, that would be pulling the voltage way down.
Now if you had just 2 batteries that were low and charging, it would only be a draw of 20A, which is less likely to draw down the voltage as much.

So in TF2's case, his were charged before installing them, which would discount the low voltage being caused by undercharged batteries. His issue must be either a defective alt or a loose connection somewhere.

I'm gonna rule out connection this weekend by redoing my big 3. Mine charged up to 12.8 but I only put them on over night. I didn't want to leave it on there longer than that. The charger showed them as charged. Thanks all for your input.

 

[TurdFergueson2 5,000+ posts]

Well, I redid my connections and still the same thing. I even changed a few things too. A Chrysler 300M has a post for the + and - because the battery is under the filter. My alt to positive was already going to it, but I was using the post for my run to the back battery. I now made both runs come ff the battery and fashioned a connection to run to the post in case I ever need a jump. A 15 minute ride to the mall and back and I was still getting low 13s when the car is warmed up. For a while it was 14.2, and then slowly dropped back down.

And in my other car, I think the voltage needs to be adjusted. I tried with both my stinger meter and my DMM and the voltage is over 15.25. That is with no load and the car running on a single battery. I thought it should be at 14.8 at the most or something like that. I've taken like 40 mile trips constantly with it like that. I looked at the battery and I see no signs of warping, but that one guys blown up battery I saw a few weeks ago scared me. Anybody not running a 16 volt system having this issue?

Cliffs: Possible bad alt being that I've changed everything but it and am still having voltage issues.

Second car has an unusually high voltage. 15.25 with the car running with a red top and 200 amp alt. No sounds yet.

 

[smoka 10+ year member]

Sounds like you are having issues with your voltage regulator. But I'm not sure how to trouble shoot that.....

For your overvoltage car, when you take a long trip try to check the temp of the batt. If it is too hot to touch then you are risking having them explode.

A batt is supposed to stay under 125 F when it is charging.

 

[TurdFergueson2 5,000+ posts]

Yeah I have been dealing with this issue and scared as hell to drive that car for long enough. I'm going to put my old alt back on and work on shipping this one back. I almost sold my factory alt last year too. Good thing I didn't.

I never checked whether or not the temp on the battery was hot. At first I thought it was my DMM, but my Stinger meter gives off the same reading. That's an easy fix though. I just have to adjust the voltage on it.