need help with voltage drops..

[vandiar2 10+ year member]

After checking all of my grounds, shortening my wires make sure fuse holders are good etc.. I am still experiencing voltage drops. battery up front is a duralast (3 years old or so) stock battery, and I have a batcap 2000 in the back right near the amps. maybe adding a batcap 800 in the back help this? batteries all rest good. checked a few days ago and both batteries rest at around 12.8 v. headlights dim pretty bad and I can definitely tell a drop off in spl after a minute or two of pounding. sometimes can hear slight distortion. suggestions? Thanks!

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[loopkiller 10+ year member]

LOL I think that you should call the guys at Batcap and ask them if the 2000 should be able to handle that 1500W RMS system. I have said before that I am not a fan of Batcaps. I would be interested in seeing what they have to say.

 

[vandiar2 10+ year member]

LOL I think that you should call the guys at Batcap and ask them if the 2000 should be able to handle that 1500W RMS system. I have said before that I am not a fan of Batcaps. I would be interested in seeing what they have to say.

man loop I really think its my front battery to be honest. there really is no telling how long its been in that car for. it looks old as hell. im thinking ditching the batcap and going to two kinetiks. I can fit a 1400 up front and put one in the back and I should be good.

 

[jco1385 5,000+ posts]

get the front battery tested at AZ

 

[SHOnOFF 10+ year member]

check resting voltages of both batts, (batcaps are great by the way so don't get rid of it unless its dead) make sure you at least have 12.2 volts on EACH batt separatly and then you probably want to upgrade your alt and ground wires to 1/0 (THE BIG 3) you should be fine after that

 

[Adrian15XXX 10+ year member]

try doing the big 3

 

[Skip01 5,000+ posts]

No need for an upgraded alt with just a 1500, assuming its working correctly

Get both batts load tested at autozone and go from there.

What's ur voltage at idle with nothing playing?

And what's it go to while you're playing it full tilt?

 

[loopkiller 10+ year member]

man loop I really think its my front battery to be honest. there really is no telling how long its been in that car for. it looks old as hell. im thinking ditching the batcap and going to two kinetiks. I can fit a 1400 up front and put one in the back and I should be good.

I would still recommend contacting Batcap first before you do anything. The front battery should not make that much difference. Since they both have a full charge, they should be good. Simply drive over to any auto parts store to have them load tested to be 100% sure. If they pass the load testing, they just are too small.

Don't just start throwing money at it yet. Figure out what you are working with right now first. If the batteries test good, then it is time to spend some //content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif

check resting voltages of both batts, (batcaps are great by the way so don't get rid of it unless its dead) make sure you at least have 12.2 volts on EACH batt separatly and then you probably want to upgrade your alt and ground wires to 1/0 (THE BIG 3) you should be fine after that

He said that both batteries are resting at 12.8 (or above). If they were resting at 12.2v they would be 1/2 dead //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[Buck 5,000+ posts]

Big 3, new upfront battery, maybe a new ground location, all 1/0, h/o alt, etc...

 

[vandiar2 10+ year member]

okay this is what I got. Tested resting voltages on both batteries again to make sure, front was at 12.88, back is at 12.9. While the car is on, front is 14.25, back is 14.2. here is the kicker.

Playing a semi heavy bass song, on volume 40 my front battery drops as low as 12.98.. sporadic of course. at the amp in the back I'm seeing 12.47 lowest. I cranked it up to 45, and put on young jeezy "put on". front battery bounces around from 13 ish to 12.45 lowest. at the amps.. the first note is 12.28. then it drops as low as 11.8 on the following notes!! just don't know. I cleaned all my grounds everything appears to be good. BIG 3 is already finished.

 

[vandiar2 10+ year member]

oh and loop, I called batcap. they said I should have NO problems at all running 1500ish rms.

 

[vandiar2 10+ year member]

You need to disconnect both batteys to check there voltages.....My 2400hc was at 14.4 and the front was 14.3 but when i disconnected my back my front was like 11.8....

man not only did I take the negative off of the front, I took the positive off too. it still rest at about 12.8ish

 

[Skip01 5,000+ posts]

Like I said get them properly load tested, Autozone can do this for free.

My NSB125 rested at 12.9 but put a load on it and it drops to 9s.

 

[vandiar2 10+ year member]

Like I said get them properly load tested, Autozone can do this for free.
My NSB125 rested at 12.9 but put a load on it and it drops to 9s.

omw right now to autozone to have this test.

 

[loopkiller 10+ year member]

Van you are doing everything right. As long as both of those batteries come back tested good, there is no reason for it to drop that far. Let us know what the battery testing says. They are going to need the CA or CCA ratings for both batteries in order to load test them correctly. IIRC that Batcap 2000 is rated at 2000 CCA. At least that is what their eBay listing says. Their website gives basically no info at all.