Ok I used 6v tractor batterys once I think they were Excide 3EH extreem duty batteries with 2 of them wired to 12 volts. For One, each battery is just under 7 volts so when you wire them to 12v you actually get almost 14 "standing". These are oversized tractor batteries so they are big. They are pretty cheap as well like 105.00 each. Also they have really high Amp/hr rating . There large size helps deal with heat during discharge also. They have really good warranty as well, I think they are 48 month free replacement. Only drawback is there size
The application I used them on was a Tahoe that a buddy of mine had me build. It was a budget bass machine with 6 audiopipe APSM 2000's strapped in pairs on 12 sundown E15's (2 amps strapped running 4 subs each). Also had 3 PPi 900.4's running 4 neo 10's, 4 neo 8's and 2 sets of sundown components. All running off of a 2nd isolated 140a alt charging 6 of the tractor batts wired in pairs to achieve 3 sets of 12 volt banks.
Worked great we are gonna fab another bracket soon so he can run another 140 amp alt, however the single alt keeps up pretty well.
To answer the cca question, CCA's are an indication of the batteries ability to discharge. It is not an exact figure but an indication.
