Thread: trunk battery

sold my 07 sti few months back, but kept my brand new optima red top. my older bro left his se-r wit me about a year ago (in the navy). its my daily, but since i dont have sti payments anymore, im boosting the sentra. anyway, id like to move battery to trunk, and just want to double check wiring with others. is this correct? excuse the drawing, but trying to keep it simple. thanks

[img][img]http://www.sr20-forum.com/usergallery/75504ecb0675d40b0.jpg[/img][/IMG]

Looks solid to me dude! Just make sure you have good grounds- Remember to sand off any paint where the grounds come in contact with the chassis and body too. Make it metal to metal contact, otherwise you are definetly good to go!

The only problem I see is the connection from the alternator to the battery. Don't do that. Leave the alternator wiring alone. However it is set up factory is fine. It really goes to your distribution block if you want to get technical about it. That will be obvious when you get working though.

thanks for the info. I was under the impression that the altenator was connected straight to battery for charging so that power to car and charging from alt to battery wasnt on same line.... but if factory setup is fine, works for me. thnks

Yeah actually now that I look at it- alternator to battery?? might wanna check that out- (Didnt have my morning coffee yet:roflits a good diagram though- i have my red optima in a Battery box in the trunk of my B13 too. Youll feel the handling become a little more netrual and predictable since that chunk of weight is shifted to the rear.

Electricity flows from high potential to low. When things are working correctly, while running, the alternator will always be at a higher output voltage than the battery. When things are working correctly, the battery really isn't doing anything, the alternator is actually powering everything. (That's a little simplified, but essentially what's happening).

So the current doesn't flow from the alternator to the battery and back, it flows from whichever source has the higher voltage to whatever resources are drawing it.

So the upshot is, don't muck with the alternator wiring, like Ben said. Everything that was connected at the positive terminal of the battery in the stock configuration should be connected to your distribution block.

One thing I would consider adding, since you're now going to have a nice long run of very heavy wire through the cabin from a power source capable of putting out hundreds of amps (and making your life really unhappy if that wire got nicked or abraded and shorted out), is to add a high-amp circuit breaker at the battery. 150A should work fine. I've done this whenever I've relocated a battery.

cool. thanks for the explanation on the voltage, and will def get a cicuit breaker. looking forward to getting this thing up nd running....

Awesome info! Im going to relocate my in Optima in a new battery box for my B15 as well and was really wanting to add a circuit breaker too. Im assuming its not too complex to add one in right?

When i did the B14 i used a distribution block. The battery, alt, starter, and power to the fuses & relays all went to the distribution block. I put a breaker at the battery and on the alt wire.