SPL Trunk 'Wall' Build Log

[Jonnyswboy]

This is going to be a pretty slow build log as I am still waiting on most of it in the mail. Everything will be in the trunk to retain back seat functionality.

2010 Mazda 6 2.5L
2x Nsv5 12s D2
5ft3 Net @ ~28hz w/ 78in2 port (Thanks @Buck)
Sundown Salt-8 @ 0.5 ohm
80AH Yinlong
Singer 390A (15.2v charge)

It will be a "wall" sealed off from the trunk.

Only Kilmat installed so far.

Wiring (2/0 is thick lines, 1/0 thin lines):

 

[AnthonyO]

What do you think of that kilmat?

 

[Jonnyswboy]

What do you think of that kilmat?

It's awesome. Butyl is butyl though, so get the thickest you can find for cheapest per ft3. I might avoid it if you live in a CRAZY hot climate though like Arizona. Mine was smelly for a couple days but it went away completely.

 

[AnthonyO]

It's awesome. Butyl is butyl though, so get the thickest you can find for cheapest per ft3. I might avoid it if you live in a CRAZY hot climate though like Arizona. Mine was smelly for a couple days but it went away completely.

Thank you. Thats what I have for my doors. Gonna be doing it next weekend. Was gonna do it this weekend but it rained the whole [email protected] time. I gotta buy some .25" plastic to cover the holes in the doors when I do it. Trying to get some midbass, right now its lacking.

 

[hispls]

Nice. Can't wait to see how this turns out. Do report back on how well 80AH hangs on that SALT amp. That's potentially really pushing those cells to their limit there.

 

[Jonnyswboy]

Nice. Can't wait to see how this turns out. Do report back on how well 80AH hangs on that SALT amp. That's potentially really pushing those cells to their limit there.

Yeah I'm a little worried about it. If my alt puts out 300A I would be asking 500-600A from the battery assuming 65% efficiency on the amp. I know it can do it for at least 12 seconds but I don't know if that will be sufficient. I would hope pauses in music will allow me to recharge. Want to clamp 8k but I could always settle for 6-7k if I need.

But I think it will be okay as I won't be drawing full current at every frequency.

 

[hispls]

If my alt puts out 300A I would be asking 500-600A from the battery assuming 65% efficiency on the amp

You will be drawing more than that until the alternator can load down. Those cells are MAX rated 10C (800A out of your 80AH bank). I have not pushed mine anywhere close to that. Personally I'd suggest doubling your LTO bank, if you can triple it you would have a hard time getting your volt meter to move more than a couple tenths of a volt, but double should be a good bit safer.

Keep in mind, if used 1C those cells are meant to give like 24,000 cycles. That cycle life drops quickly as the charge/discharge demand increases as will overall discharge performance. I look at mine as a very long term investment and I paid high going in so that I'd optimize life expectancy and have worry free performance along the way.

 

[Jonnyswboy]

You will be drawing more than that until the alternator can load down. Those cells are MAX rated 10C (800A out of your 80AH bank). I have not pushed mine anywhere close to that. Personally I'd suggest doubling your LTO bank, if you can triple it you would have a hard time getting your volt meter to move more than a couple tenths of a volt, but double should be a good bit safer.

Keep in mind, if used 1C those cells are meant to give like 24,000 cycles. That cycle life drops quickly as the charge/discharge demand increases as will overall discharge performance. I look at mine as a very long term investment and I paid high going in so that I'd optimize life expectancy and have worry free performance along the way.

How long does it take until the alternator is loaded?

I will probably evaluate the performance of just the two banks and then consider adding more. Do you think that I would even be able to clamp 7-8kW with just 80AH at the expense of the longevity? Is doubling to 160AH the difference between holding 15.2-14.7 or dipping to 13.3-12.5v? I just want to know how long I can draw 700-800A from my system before the battery is dead and I am just using alternator. (Not that I want to cycle the battery several times a day).

I've seen people running similar setups and they report positive results. One guy I talked to had one 80AH on a BC17k at 0.5ohm on one 390A alt.

Thanks. My previous build was 1500RMS so this kind of power draw and lithium are new to me.

 

[hispls]

How long does it take until the alternator is loaded?

Probably depends on the alternator and the regulator but definitely NOT instantaneous like the battery will try to do and consider whatever the alt is rated is cold, on a test bench, and at optimum RPM, real world performance may vary.

I just want to know how long I can draw 700-800A from my system before the battery is dead and I am just using alternator.

By the numbers 6 minutes if the bank is 80AH. Of course amp hours are probably NOT rated at 10C and your voltage will sag as you discharge and sag faster the harder you're pulling. And running it at 10C regularly will dump your cycle life to probably 1000 or so as opposed to 24,000. Cycle life going down to C rate going up is NOT linear relationship.

Then again, it may be with your box and music listening you're rarely drawing more than 400A and you're in much better shape with very infrequent 10C peaks. You really won't know for sure how well it holds up until it's all put together and you put the spurs to it.

 

[Buck]

That killmat looks well done!

 

[Jonnyswboy]

Rear deck cut and sub floor in. Brainstorming ways to secure it to the floor.

 

[hispls]

Not to piss on your parade here, but if you're aiming to completely seal off the trunk from the cabin why throw all the deadener into it?

 

[Jonnyswboy]

Not to piss on your parade here, but if you're aiming to completely seal off the trunk from the cabin why throw all the deadener into it?

Big dick energy

 

[Kickstand]

If your going to use the trunk as a box it's probably better if it doesn't rattle to hell and back

 

[SlugButter]

My OCD would never allow me to not deaden that, necessary or not. Looks good.