Where are you putting yours?

I'm putting a ~3-5 gal methanol tank under the pass front bed corner, accessed through removable rear inner fender. I know NASCAR teams put one battery forward of each rear tire, and the driver side has the fuel tank/fuel neck.

I imagine you'd have to use a marine box for second battery if you place it under the truck...and I'm not sure how you put a 2 battery parallel system on a modern vehicle...our camaro we had the dual optimas tied with #0 welding cable, with a #0 going to the front of the car and a #8 alternator cable. But I thought I read that 2 batts messes with modern charging systems.

 

i plan on mounting it in a box, on the top of the spare tire carrier, and underneath it is gonna be my air tank. to keep it from fckin with the vehicle main battery, im plannin on finding a back feed preventer, ie a check valve for electricity. if such a thing exists.

at first i thought we hijacked the forum from its original topic, but its still possible soultions for the issue

 

heres an isolator,

http://www.awdirect.com/battery-isol...130114050944:s

 

Basically a relay-diode over solenoid system.

In normal operation, there is a common ground, and a diode on the positive line that allows a trickle current to come in (Minus the 1.8V drop across the diode) to charge the secondary battery but no current to go out. A zener diode triggers a relay if an over/reverse current situation exists (IE alternator fails or there is a >5 volt voltage difference). To enable jump starting, it engages a solenoid that bypasses the diode-relay circuit and allows the batteries to be parralled for starting.

At least, that's my understanding. I'm still learning my circuit stuff.

 

so something like this ?

http://www.amazon.com/PAC-PAC-500-50.../dp/B001YIPXR2

 

It's hard to explain.

A regular isolator solenoid does one thing- connects the battery, or disconnects it.

An isolator allows the secondary battery to charge with the primary, but be in use without effecting the primary.


Solenoid: Both charge, Load on primary may also draw from secondary, load on secondary may draw from primary. When disengaged, batteries/loads are isolated, but secondary may go dead because it will not be charged.


Isolator: Both batteries always charge together. However, a load on primary will not draw from secondary, a load on secondary will not draw from primary. Usually has a mode to allow the 2 batteries to go parallel (See: Solenoid) for starting with a heavily discharged primary or when the power of both batteries is needed to run a load.

A cheap isolator solenoid is a ford starter solenoid. They are rated for constant use without overheating.

 

ford starter solenoid huh? you wouldnt happen to have a part number handy would ya?

 

Go to O'R/AZ/NAPA and ask for one. They're the same from the 50's to the 90's. I don't think they even have a model number, they're that generic. Haha

 

ooo i know what your talking about... when i worked at uhaul id have to rig trucks so we can start em and move em and get new keys made for em.. wed get them to on,, but no start.. so wed jump the solenoid with a screwdriver and it would fire the truck right up

id probably get one for a 96 f350 diesel.. haha big power rating there..

 

Believe they're all the same. Diesels may be different. But some solenoids are rated continuous duty, some aren't. Also depends on how much current you're flowing.