how batteries discharge

Well hopefully with the truck running and system at full listening volume, the voltage never drops that low...! I dont think that would constitute a cycle though...? Actually draining the battery to 10.5v and then recharging would...I get wanting to add a second battery...Whats the voltage dropping to with the"low bass note" currently...10.5v...? Adding a 2nd battery means the alternator now has to charge two batteries,instead of one. Also there is adding an Isolator ,if you are running two batteries. What kind of battery is under the hood now...Have you upgraded The Big 3 yet...? Im assuming that you are experiencing low voltage or lights dimming currently,and is why your leaning towards  adding a 2nd battery...!M.E.C.P & First-Class

Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

No my voltage doesnt drop to 10.5v. It gets down to about a steady 12volts. Right now im running a kinetik 1200 under the hood but another 1200 one would not fit behind my backseat so I want to go with a HC800 (closest to its size that CAN fit behind my seat). Yes i've done the Big 3 and My voltage with car running and no music went from 13.5v to 14.28v. My lights Are dimming so i think i just have a sensitive electrical system and im trying to get it to maintain itself at 13v. And like you said I dont want to get a second battery thats tooLarge, because I dont want to put to big of a load on the alt. Personally i wouldnt mind going with the HC600. I know you we should go with the same EXACT battery but I'd rather spend 80 dollars next year than 1500$ trying to get a replacement for my alt. Because 2004+ Ford F150's Does not have a choice of Alt upgrades. They have specially designed for it to be the only alt that can fit unless that part of the engine is rebuilt. I can't hear you!

What size wires did you use for the big 3...? Its a factory alternator...? I think the problem is more that you need more current being introduced...As opposed to adding 2nd batteries...! Maybe just save the $ untill you can upgrade the alternator...?!M.E.C.P & First-Class

Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

well if i save that will take about 2-3 years.. im working on a electrical engineering degree at UF. Tuition is serious since the championships... i need a steady current NOW. Before i blow another amp.I can't hear you!

As far as alternator upgrades...Have you checked out Ohio Generators...Well as long as you used the correct size Power Wires...Have a Ground that has been verified good w/ multi-meter and is also the correct size...I just dont think adding a 2nd battery is going to help... What size power and ground wire do you have...? What size wire did you use for the big 3 upgrade...? What size speaker wires from amp to sub box...? How long is your ground wire...? Just want to get a clearer picture here...! And maybe i missed what amp,subs,etc...!? Just for the hell of it ,please list where and what size you upgraded the factory wires to...?M.E.C.P & First-Class

Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

Amps- Hifonics BXI-2408D 200amp Rockford Fosgate T3002 80amp Subs- 3 Pioneer TS-W2501D2 wired to 1.3ohms (12 Gauge Wire) 4 Door Speakers (16 Gauge wire) 0 AWG for Big three. 0 AWG Power and Ground To Hifonics Amp (Ground 1.5ft) 4 AWG Power and Ground wire to Rockford Amp (Ground 1ft) For now I just want a little reinforcement to keep the Voltage atleast about 12v. And So now im think about buying one of the Small kinetiks to use just for now. i'd rather have that and it help than have nothing and a amp burn out because of low voltage. PS: and I just emailed OHIOgen.com and asked.I can't hear you!

The Voltage right now gets down to about 11.5 at the LOWEST. And thats at long notes (4-6sec) like it has to kind of work its way down. But i feel that thats not too good . I think I may have found a place that can either make or customize a 200amp alt for my truck for cheap. Im waiting on the email reply. And if he says yes then I wont worry about the Battery until I get that. But if not I will definately post the results. Thanks for the Help!I can't hear you!