When is a 3rd battery needed? voltage questions

[Sir Pay 10+ year member]

For the guys pushing multiple batteries.

I have 2 optima red tops installed (1 under the hood/1 in the cargo area) and was wondering if i should install a 3rd battery in the cargo area? I have an some fairly large screens along with 2 13w7's. my H/O alt died so im pushing the stock one for now. Would a 3rd battery help me out @ all?

If im idling with all the screens on and the music @ anything over 1/4 of the volume, the screens will alternate power... Im either going to upgrade to 2 amps to power the subs or or upgrade to a 2k-3.5k amp. i have a 200 amp isolator and wanted to know if a 3rd 34/78 will help? or should i sell the battery and just get a new alternator?

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[disturbed471985 5,000+ posts]

Sell the two red tops and replace with something better. HC2400's, Deka's, etc. 2 good 100ah batts will be better then 3 of those red tops.. But the best thing would be to buy an alt.

 

[retrojordans 10+ year member]

For the guys pushing multiple batteries.
I have 2 optima red tops installed (1 under the hood/1 in the cargo area) and was wondering if i should install a 3rd battery in the cargo area? I have an some fairly large screens along with 2 13w7's. my H/O alt died so im pushing the stock one for now. Would a 3rd battery help me out @ all?

If im idling with all the screens on and the music @ anything over 1/4 of the volume, the screens will alternate power... Im either going to upgrade to 2 amps to power the subs or or upgrade to a 2k-3.5k amp. i have a 200 amp isolator and wanted to know if a 3rd 34/78 will help? or should i sell the battery and just get a new alternator?

You need a 350+ amp alternator not an Ebay special "High Output Alternator"...A nice HO Alt will run roughly $450. Forget about batteries until you get a proper alternator. While the vehicle is running it draws on it's alternator for power not it's batteries. If your system is steadily drawing power from your batteries you have serious issues.

Get a proper alternator not a cheap one.

 

[Sir Pay 10+ year member]

it was from DB electrical i hadn't heard anything negative about them...

DB Electrical - NEW High Output Alternator Chevy Suburban 03 04 05 06 HO-8292

voltage regulator went bad on it i was told...but this time i will go a different direction.

 

[SPLaudio 5,000+ posts]

u dont need a 350 amp alt. you need 200 and 2 maybe 3 reall good batterys...

 

[rc10mike 10+ year member]

I have a 200a alt and just recently removed my rear Kinetik HC2000. Im still running my same setup (DDs4 and a JBL BpX2200.1) and my voltage still doesnt drop below 13 ever...and thats with about 2600w rms

I would say invest in a good alt first.

The way I understood it was that extra batteries only help if the alt cannot keep up, after that extra batts help keep the voltage up until the alt can recover..

 

[SPLaudio 5,000+ posts]

my last car had a 90amp,alt. stock wet battery and a c&d liberty in the trunk i had 3500k of power and playing music going down the road it would NEVER drop below 13v...

 

[SPLmatic 10+ year member]

my last car had a 90amp,alt. stock wet battery and a c&d liberty in the trunk i had 3500k of power and playing music going down the road it would NEVER drop below 13v...

3,500,000 watts eh?

 

[tpmeredith 10+ year member]

i agree with corey, a 200amp alt + a good battery in the back like a deka or something would work fine. I'm running close to 3000 watts with a 135amp alt and rarely drop below 14v