How do I hook up 2 car batteries?

BillyGalbreath · 04-28-2008, 09:35 PM

Ok, so after much research I ran across a diagram for a "Diode Battery Isolator" and it seems like the solution I am looking for.

I plan on upgrading my alternator (further research is needed to determine what kind/size/etc) to handle my needs. I will upgrade my existing main battery to a Red Top Optima Deep Cell (I've read these are better for starting engines) and adding a Yellow Top Optima Deep Cell as my accessories battery (I've read that these drain slower and are not so good with starting engines). I will separate these batteries with a battery isolator (just learned they existed last night).

Now, all together I plan on having about 3500+ watt usage out of my Yellow Top to power all my accessories (3 amps, 1 inverter, & my Lilliput), which is why I decided to go with such a heavy duty battery.

Here is a link to the diagram I've found: http://www.custombatterycables.com/i...20isolator.GIF

Now, my question to you is: Is this a good idea or is there something better that I haven't come across yet?

Thanks!

rgarjr · 04-29-2008, 04:09 AM

Well the main purpose of having a second battery is to be able to play with your gear when the engine is not on. So if you play a lot, then yeah a second battery would be good.

BillyGalbreath · 04-29-2008, 09:25 AM

Yeah, I'll be using it a lot with the engine off. Does the diagram look correct?

marchello2000 · 04-29-2008, 11:23 AM

Quote: Originally Posted by BillyGalbreath

Yeah, I'll be using it a lot with the engine off. Does the diagram look correct?

It looks fine to me, but you realize there are inherent problems in the diode isolators? Because it is a silicon device there is a voltage drop of at least 0.5V. That will generate ALOT of heat if you are planning to drain lots of current through this. So make sure you have a nice heat sink there. If this is unacceptable then I would suggest the solenoid approach (basically, the switching is done by a relay, not solid state components)

BillyGalbreath · 04-29-2008, 11:12 PM

Quote: Originally Posted by marchello2000

It looks fine to me, but you realize there are inherent problems in the diode isolators? Because it is a silicon device there is a voltage drop of at least 0.5V. That will generate ALOT of heat if you are planning to drain lots of current through this. So make sure you have a nice heat sink there. If this is unacceptable then I would suggest the solenoid approach (basically, the switching is done by a relay, not solid state components)

Do you have any links/images/diagrams for me on this solenoid method? Thanks!

TecH4HirE · 04-29-2008, 11:46 PM

Here is something I found when I wanted to use 2 batteries for lots of accessories.

http://www.hifisoundconnection.com/S...9420/SFV/30046

Good Luck.