Voltage drop

[DAMONMCHALE]

Hi all, I have a system running about 1500watts rms and I'm having major headlight dim and voltage drops to 11.5v on a sub hit. I have the big 3 upgrade done already. Everything is still running on the main battery, would it help adding a second battery? Like a kinetic battery with an isolator. I'm trying to avoid having to drop $600 on a HO alternator. Is there a difference between a capacitor and the kinetic battery's?

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[dev199505]

Get your current battery checked first upgrading that to a AGM might be enough

Sent from my Z812 using Tapatalk

 

[DaytonLax14 10+ year member]

ditch the lead acid battery and get the biggest AGM battery you can fit in your battery tray. Then check voltage. Boom done.

 

[HI-C 10+ year member]

^^^^^what they said ^^^^^

 

[tc300 10+ year member]

agm battery is a MUST!!!

 

[DAMONMCHALE]

They don't sell a battery to fit my car. It's a brand new interstate battery. Would it be ok to get an agm as a second and keep the lead acid in the front?

 

[macsdad 10+ year member]

Get with mylows10, he can help you find the closest for your particular vehicle, he helped me with mine, pretty close to oem as well.

 

[DaytonLax14 10+ year member]

They don't sell a battery to fit my car. It's a brand new interstate battery. Would it be ok to get an agm as a second and keep the lead acid in the front?

what is the group size of your stock battery? and did you actually measure the dimensions of your battery tray before posting this? I find your response hard to believe.

And no, do not wire a lead acid with an AGM

 

[DAMONMCHALE]

Group 41 battery fills the tray perfect. 7" x 11.5" is the tray dimensions. I couldn't find a group 41 agm. Why does your response have to be rude? I was never planning to put an agm up front and my response was sent in the middle of my work day so no, at the time I did not measure it.

What's the reasoning for not running a lead acid with agm?

 

[DaytonLax14 10+ year member]

Group 41 battery fills the tray perfect. 7" x 11.5" is the tray dimensions. I couldn't find a group 41 agm. Why does your response have to be rude? I was never planning to put an agm up front and my response was sent in the middle of my work day so no, at the time I did not measure it.
What's the reasoning for not running a lead acid with agm?

My response wasn't meant to be rude, I just found it hard to believe that there isn't ANY agm battery that will fit in your battery tray. I'm pretty sure a group 48 is the closest size to a 41

The issue with mixing AGM and wet cell batteries is the float voltage. AGMs float quite a lot higher than wet cells normally so there will be a charge imbalance between the batteries. Since everything will tend towards equilibrium the batteries will constantly try to balance themselves out which eventually results in everything being flat. But, many people mix lead acid and AGM with no problems while some people have problems. I'd stay on the safe side and not mix the two together but that's just me.

 

[mikepro89]

For the average daily driver is there much of a difference between getting the biggest cheap agm I can find vs getting a "sspecialty" agm battery?

 

[wew lad 5,000+ posts]

For the average daily driver is there much of a difference between getting the biggest cheap agm I can find vs getting a "sspecialty" agm battery?

The biggest difference is Virgin vs non Virgin lead and warranties. Other than that all batteries are made by a few major companies