40AH lifepo...Still Have Voltage Drop

[illridge]

I'm still dropping into the low 12's or lower with 40ah lifepo4 bank.

I'm trying to run ~2-3k rms.

Stock gm alt is 160amps.

Largest draw i've clamped on my jp23 is 120-140 amps on music.

I've clamped my alternator-- normally 40-50amps@ idle.

So where is my weak link?
40ah of lithium just not enough capacity or i got something else going on???

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[metalheadjoe 10+ year member]

I suspect they found a defect in these batteries, and that's why they discontinued them so soon.

 

[Boominburban]

Thats only 3-4c tops draw on that battery. How long are you playing at that amp draw before it starts dropping voltage?

 

[illridge]

It'll probably drop in a few minutes.. depending on how hard I push.
Checked some measurements tonight....
JY40 will draw only ~50amps when you first start the car.
It will stay pretty consistent for a few minutes until the voltage climbs up to 14.0

The battery/ car sits at 13.2v with the key off. Agm up front hooked in parallel.

Sub sits at 1.4ohm nominal--- just checked that tonight too.

Amps never drew over 40amps tonight, so no voltage drop to test....
But i bet i'll start sagging with 100amps continous draw

 

[illridge]

added a 32AH bank to my system......
Cot damn! Now we rockin.
Voltage staying above 13 wide open!!

Just thought I'd update.