Quick questions for the experts please.
I just finsihed finally ordering two deep cycle batteries for my setup, I probally should have asked here first, but was told by the dealer that if I bought two exact batteries that I could simply wire the batteries in parallel without a isolator like the one I have used in our RV (however, I believe that was because the altenator was low output, and isolation of the main battery was desireable to protect it from drainage that would leave the RV unable to start?). The Optima 31T and 31A are the both 75amp hour/155min reserve deep cycle 1125 CCA optima yellow tops, internaly the same, except the one for the engine compartment has posts (A) and the one for the rear has threaded terminals (T).
I have a rewound Ohio 260amp alternator that has been retro'd to accept 0/1 power wires, my original interstate battery had 0/1 to the alternator as well as 0/1 to rear distribution block, with 0/1 ground feeds to the factory negative point as well as directly welded to the frame member. The dealer told me to simply wire the negative to negative, and positive from the engine compartment to the positive of the trunk battery, and feed my capacitor/distribution input from the positive from the 2nd batteries positive feed. I intend to connect the 2nd battery negative directly to the vehicle frame with 2 0/1 feeds as short as possible rather than negative to negative.
A rockford fosgate 200amp circuit breaker is mounted @12" from the front battery positive, and I plan on placing a 2nd 200amp breaker inline (between the front +12v post to the rear +12v terminal @12" from the 2nd battery positve), finallizing short protection with a 3rd 200amp breaker inline @12" from the 2nd battery positive onroute to my old fused distribution block/capacitor.
[Question] : I have seen online wiring recomendations showing +12v feed #1 going directly to the distribution block, and a 2nd +12v feed from the distribution block back to the 2nd battery positive.
Seems cleaner to do it as I originally mentioned first with with wiring from +12batt-1 to +12batt-2 and then from +12v batt-2 to cap/distribution block (with breakers placed as mentioned above). Comments please? Is it a matter of aesthetics only?
[Question]: Is there a need to direct connect the front and rear negative's to each other? Am I being fed a line on the hookup requirments, or is he correct. I plan on seperatly grounding each battery to the frame as mentioned previously.
This my first two battery setup, I plan on doing more reading later, but figured I'd post these questions here for audio professionals to comment on.
Comparing your proposal to connect batt1+ to batt2+ to this diagram dual batteries without an isolator at BCAE, it looks to me that the 2nd breaker you will install at battery 2 will ensure protection of the linking wire. I would think that wire protection is the primary reason for running each wire to the distro. So one should be same as the other, as long as the positive wire out of battery 2 is large enough for all power.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
My distribution block is fused per the diagram, If I went with the positive to positive connections, I would have 2 breakers on the connector. Simply to protect against a short anywhere along the length of the lead. A 3rd breaker would be between then rear battery +12 adn the distribution block. I think the addition of the breaker at the rear +12v between the two +12v's would protect this feed. So basically, if I was to get a short in the +12feed from front to rear, the link is protected, and then the 3rd breaker between the rear +12 and the fused distribution protects any shorts possible between the 2nd battery and distribution point. I have a really nice 5farad capacitor/voltage display/distribution setup with only 1 0/1 input on it, this is the reason I am trying to stray from the bat1+ to dishtro, and bat2+ to distro. But I will wait for some more comment, dont want to do it wrong...
OK, I see your reasoning for this now. Yeah, get feedback from others because I certainly am not an expert at two-battery wiring.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
You have the right idea septicdeath, the only thing I see that may be an overkill is the 3rd breaker. Generally, the run from the rear battery to distribution point isn't that long, therefore if there is a short, the fused distribution will catch it quickly, as where with the run from front to rear, you do want protection on each end, as you have stated, to protect in case of a short.
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