redcobalt07

iTrader: (18)

So I know how to wire up a battery isolator. I have the isolator. Run a power wire from each post of the isolator to each + battery post. Then a true igniton source and a ground. My question is, how does the second battery get charged from the alternator? Is it when the true ignition turns on, the charge going to the main battery then goes to the second battery as well?

brickloaf

you can save yourself alot of trouble by just wiring the 2 batteries together in parallel...

both batteries get charged and you dont need an isolator

redcobalt07

iTrader: (18)

yes but wiring in parallel causes them to drain each other so they are both equal. So a 14 volt and a 10 volt will equal out to 12 volts each which isn't what I want.

brickloaf

not really sure what you mean since most car batteries are 12v...you can get higher voltage ones but ive never head of a 10v?

redcobalt07

iTrader: (18)

I meant if one 12 volt battery is dying and at 10 volts

murphy0789

iTrader: (1)

You need an isolator for two batteries or it will kill both batteries they drain and equal out which just kills it. When you receive power from the true ignition source it allows the batteries to basically be in parallel to charge both batteries off of your alternator and allow your vehicle to pull from both batteries during starting, when the power shuts off the batteries disconnect from each other and keep it from draining.

redcobalt07

iTrader: (18)

exactly!

murphy0789

iTrader: (1)

Did you find a line to use for the true ignition source? Im waiting to hook my dual battery setup this thursday with a Dual 7" HU.

redcobalt07

iTrader: (18)

I planned on using the fuel pump line since I am already tapped into that for the IC pump.

murphy0789

iTrader: (1)

Did you just tap into the fuse then or the actual wire?

redcobalt07

iTrader: (18)

the fuse, otherwise you could try the ignition wire

murphy0789

iTrader: (1)

Alright thanks for the help that was my two thoughts igniting or fuel pump.

redcobalt07

iTrader: (18)

On the instructions it says the alternator which I might since I'm replacing that too

murphy0789

iTrader: (1)

See thats whats weird my instructions says nothing about alternator just a true ignition source. I think I will just go with the fuel pump fuse will make it a little easier I think. I had read on some tutorials to use the alternator so idk.. Either way I will make it work.

redcobalt07

iTrader: (18)

The alternator can also be used for a true ignition source.

brickloaf

i gotcha, but ive had 2 batteries ran in parallel for at least a year or so and the only time my batteries died was when i left my headlights on all night..