has anyone noticed a big difference in a second battery?

[mustanggt5330 10+ year member]

im runnin around 2,000rms, big 3, yellowtop under the hood.

 

[22mountaineer 10+ year member]

im runnin around 2,000rms, big 3, yellowtop under the hood.

That dont sound to good..

I had a 250A EA alt, voltage still dropped with the big 3.. Added a NSB 90 to the MIX and voltage DIDNT MOVE

 

[mustanggt5330 10+ year member]

i got a stock 130 alt.

 

[mustanggt5330 10+ year member]

bump..............

 

[mustanggt5330 10+ year member]

bump....

 

[mustanggt5330 10+ year member]

up......

 

[Lakota 5,000+ posts]

My second battery (Kinetik 2400) has helped a bit with voltage drops but hasn't made as near as big of a contribution as my ho alt.

 

[mustanggt5330 10+ year member]

hom much can a 200alt,yellow top, bid 3 0g everything....suport?

 

[Etac 10+ year member]

i didnt read everyones post so hope im not repeating anything... but i was having voltage drops.. and did the big three (on my old car) and the bass sounded a lot better.. held the notes deeper and longer..

 

[jco1385 5,000+ posts]

when i put my g31 in the trunk, it was night and day. went from crazy drops to almost none

 

[cocoleveo7686 10+ year member]

ive read everyones post and im not trying to argue with anyone im trying to learn, but if you have 2 batteries wouldnt it be harder on a STOCK alternator about 110-130A then it would be on a 200A alternator? everyones telling him to get another battery, what if he had a deep cycle battery upfront and the big 3 done, i dont think another battery would help because then the altternator would be having to charge 2 batteries instead of 1, at that point i think he woudl need to get an alternator am i correct?

 

[donpisto 5,000+ posts]

I sorta have a feel what you're working with. I have an RF T30001bd and I had it on my stock 90A alt and Odyssey PC 1200 and it got a lot of voltage drop. I threw in a 170A alt and at the amp, not the battery, the voltage was 11.4V with the vehicle on at idle. I'm going to be adding an Odyssey PC 2150 and that should help quite a bit, however I will be putting in another 4 channel and I do want to keep voltage up as high as possible. I want to be clear of the 12V range so I'm adding a second 2150.

In my opinion, you would need a deep cycle battery under the hood (as large as you can fit), the big 3, an HO alt, and probably even another large deep cycle in the trunk.

 

[helotaxi 5,000+ posts]

Ideally you want both a second battery and a high output alt. The alt makes the power, the batteries are there to stabilize it. A single battery can only handle so much current draw before the float voltage (whatever voltage the alt is charging at) is drawn down to the nominal voltage (12 V thereabouts) It's very little strain on the alt to put the battery back to float voltage unless the battery has been pretty deeply discharged. With the car running and playing music, not test tones, this will pretty much never happen usually even with just the stock alt, since the current draw with music does not average out to a very high draw and is nowhere near continuous.

If you have ever used an air compressor, it really is a good analogy. The compressor itself is pumps the air into the pressure tank just like the alt keeps the batteries charged. When you demand air from the system, the tank provides the initial hit of air and then the compressor kicks in to maintain the pressure for long term demand and to get ready for the next big demand. The alt and the batteries work in a very similar fashion. The alt provides continuous power to the system, but it does not react well to rapidly changing current demands, the voltage goes all over the place. The batteries act as a buffer to take the bit current hits and keep the alt from having to try to rapidly change output. The overall demand on the alt is actually reduced by having a good buffer in place. A really huge cap (100 or so Farads) would do this if the high ESR of a cap didn't drop the voltage below a usable level before it even leaves the cap.

 

[PSturmer 10+ year member]

dropin below 12 and dont know if its worth it.. i wanted someone who had exsperience in doin this with good results....

i had a setup with 2 2600 watts amps @ .5 ohms each and on music with 2 batteries and car on i could not get my voltage below 12. i have a stock alt

 

[BassAddictJ 5,000+ posts]

2nd battery helped ALLLLLLOT for me. just be smart and only bump when you're rmp's are up alil...if you bump while at idle you (A) look stupid and (B) drain your batteries quicker.

first do big 3, from there add a 2nd battery, if voltage still isnt stable then you definitly need a new alty