I have a Q about mixing batteries. I'm about to put in an order with Dale, but I've heard two things. The plan was to get one XS power 2700 for under the hood, and one 3100 for out back. I wasw also told to leave the stock up front, and run two 3100s in the back.

It is a 91 grand voyager, with the front stage running off of the front battery, and a Memphis 4k in the back. Please help.

 

Hey kirby I don't got the brains to answer u, but why don't u just call up dale in cranny he could tell you! Goodluck bro

 

Mixing batteries without using an isolator of some sort will really reduce the life of the batteries and will cause them to drain out due a difference in ESR's. No problem at all mixing batteries if you are using an isolator. The type I reccomend is just a bigass relay. The Diode isolators are not efficient and are a parasitic loss on your system.

Your local Co-op or farming supply center is your friend. White Westinghouse makes 300A relays and are around $35-40 each. The same relays are re-branded by other audio specialist companies and sold for $150+

 

Batteries draining each other is one of those bad myths that never seems to die. Each battery in a multi-battery system will charge and discharge proportional to it's capacity. When left to stand they will not drain though each other's ESR, the output voltages will simply vector sum to zero. This is a fancy way of saying they will just sit there and keep the same voltage. If one battery is faulty however and continually drains on it's own, it will eventually drain the other. This is a fault in the battery however and not the parallel connection scheme. A faulty alternator or other parallel connected piece of gear would do the same.

 

^^ well then there ya go^^.

 

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if you gto a 27 and a 31 on order jsut run the 27 undr hood and teh 31 in back and it will work fine, but if u want 2 31 then leave teh one under hood and runa cahrge wire toback but make sure you fuse tehm front/ rear