Help with Batteries For Daily

[Blackout67]

My setup is pretty much done appart from maybe getting some different door speakers and a battery.
I already have a single Group 34 AGM under the hood but it has trouble keeping up with my amps. I need a battery for 270 amps worth of power (combined fuse rating for amps). I rarely sit and play music and I'm usually driving around while jamming out but man I have a 15 inch subwoofer (tryna sell/trade btw) with a 4 inch coil and that baby takes some power to move it.

Firstly, how would I go about adding a second battery, secondly should I go for another AGM or a lithium cell and what would be the AH I need? I can never find a clear answer on this because everyone

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[Grimmjoww]

Lithium is the best, has stupid fast recharge rate, can drain to damn near zero with no damage and is very very light. But some are finicky on charging sources (battery chargers) and they are expensive. I personally run sealed AGM batteries with a 100AH rating or better. With whichever you choose mount it as close to your amp as possible. Run the largest OFC wire you can from your main battery in the front to the rear battery, imo anything les than 1/0 will not cut it. Then make sure you have a good ground on that new battery in the back. All of this is based on you have the BIG 3 done with a solid main ground to the frame/body.

 

[Grimmjoww]

Here is a great chart that can help. And this is copper or OFC, if using CCA or Aluminum you can pretty much double the size needed.

 

[audiobaun 5,000+ posts]

What amp/amps are you running?? What alternator do you have? Stock? If so, what is the amperage? What vehicle?. Big 3 done yet? what size is your supply for the amp/amplifiers?

 

[Blackout67]

What amp/amps are you running?? What alternator do you have? Stock? If so, what is the amperage? What vehicle?. Big 3 done yet? what size is your supply for the amp/amplifiers?

Sundown SIA 2500, D4S JP84
320 amp AutoTech Engineering Alternator and group 34 O'Reilly AGM with big 4
Not sure what you mean by the last question

 

[Blackout67]

Lithium is the best, has stupid fast recharge rate, can drain to damn near zero with no damage and is very very light. But some are finicky on charging sources (battery chargers) and they are expensive. I personally run sealed AGM batteries with a 100AH rating or better. With whichever you choose mount it as close to your amp as possible. Run the largest OFC wire you can from your main battery in the front to the rear battery, imo anything les than 1/0 will not cut it. Then make sure you have a good ground on that new battery in the back. All of this is based on you have the BIG 3 done with a solid main ground to the frame/body.

See I was looking at lithium but I've heard they don't mix well with AGM batteries. What are some quality moderately priced supplemental batteries? Preferably not the over priced name brand audio batteries (I feel like you are only paying for the name with those really) Like I said I rarely did and idle with music playing and I never play it with the car off.
Do I need a battery isolator?

 

[hispls 5,000+ posts]

(I feel like you are only paying for the name with those really)

I'm with you on this. If the O'reiley's under the hood is doing you right, throw a couple more of those back by the amp and that should hold up to that 2500 pretty well. If you can abide the weight and space they'll take up I've had good enough luck with parts store "premium" AGM lines in the past.

I have some LTO cells here if you opt to go that route but I'd suggest go big enough to delete your under the hood battery and your savings will be playing the long game as they are meant to last 20 years or 20,000 cycles as opposed to best case scenario you can kill the parts store ones a bit before your warranty runs out and get some fresh ones to stretch your money out for a couple more years.

 

[Blackout67]

I'm with you on this. If the O'reiley's under the hood is doing you right, throw a couple more of those back by the amp and that should hold up to that 2500 pretty well. If you can abide the weight and space they'll take up I've had good enough luck with parts store "premium" AGM lines in the past.

I have some LTO cells here if you opt to go that route but I'd suggest go big enough to delete your under the hood battery and your savings will be playing the long game as they are meant to last 20 years or 20,000 cycles as opposed to best case scenario you can kill the parts store ones a bit before your warranty runs out and get some fresh ones to stretch your money out for a couple more years.

I don't feel like going thru the trouble of deleting the under hood battery. I paid good money for it and when it fails I'll warranty it out no biggie. How would I go about hooking up multiple agms? Do I need a isolator or relay or whatever? Or do I just throw the battery in the back and run 0 gauge to it?

 

[Bass Addict 10+ year member]

i run 0 gauge from battery under hood to battery in cab,then 0 gauge from batt in cab to amp with inline fuses at both batteries.and grounded in cab and big 3.i use knuconceptz ofc wire

 

[Grimmjoww]

See I was looking at lithium but I've heard they don't mix well with AGM batteries. What are some quality moderately priced supplemental batteries? Preferably not the over priced name brand audio batteries (I feel like you are only paying for the name with those really) Like I said I rarely did and idle with music playing and I never play it with the car off.
Do I need a battery isolator?

Bro, I'm running a bas boat agm in the back. I got them on sale for like $150 a piece. They have 100 ah, are deep cycle and sealed. Any auto/rv sealed agm battery will get the job done at the level your at, I don't care if you get it from tractor supply. Now when you get crazy with the watts it starts to matter, you need ultra fast load and unload times on your cells, but that's a whole nother story.

 

[Blackout67]

i run 0 gauge from battery under hood to battery in cab,then 0 gauge from batt in cab to amp with inline fuses at both batteries.and grounded in cab and big 3.i use knuconceptz ofc wire

And you don't have any issues with the batteries draining without an isolator or whatever?

 

[Bass Addict 10+ year member]

And you don't have any issues with the batteries draining without an isolator or whatever?

nope.before i added a big batt in cab,i would,i would dip below 13v on a crescendo s1v2. 1680 rms at 13.8....even when i replaced that with the crescendo 2500 with the big batt in cab.i STILL dont dip below 13..and thats with a 110 amp alt lol.half gain and it was actually loud enough today to get on my nerves when i wasnt in a bassin mood....and actually,its not o gauge,its 1/0 gauge.my bad on that

 

[Blackout67]

nope.before i added a big batt in cab,i would,i would dip below 13v on a crescendo s1v2. 1680 rms at 13.8....even when i replaced that with the crescendo 2500 with the big batt in cab.i STILL dont dip below 13..and thats with a 110 amp alt lol.half gain and it was actually loud enough today to get on my nerves when i wasnt in a bassin mood....and actually,its not o gauge,its 1/0 gauge.my bad on that

Ok. So you do fuse between the two batteries and then another fuse in between that battery and the amp?

 

[Bass Addict 10+ year member]

Ok. So you do fuse between the two batteries and then another fuse in between that battery and the amp?

fuse at the batt under hood and then fuse the cable coming from batt to amp...i will throw a lil vid in to show my xcon 10 doin work after 7 years lol.you will hear some comments like feel that air.i said that because of this little bitty 10...its on the crescendo 2500 s1plus.

 

[Grimmjoww]

Ok. So you do fuse between the two batteries and then another fuse in between that battery and the amp?

I have an unfused 2/0 wire running from the front battery to the rear battery with a disconnect. I then have a fuse block between the rear battery and my amp. I do not want anything in between my 2 batteries, I want them to function as one unit, I do have a disconnect I can access quickly if anything should ever happen.