Any advice my dual battery setup plan?

[Rocky5000100]

Hi all,

I've been researching dual battery setups a lot on here and other sites the last few days.

I don't want to do anything fancy. I will mostly be using this for my motorcycle track days to power a fan while sitting around the paddock, cell phone, radio, laptop, possibly a refridgerator someday, and maybe a 120v air compressor.

I got most of the ideas from this thread:

How to make a cheap isolated dual-battery setup for $50 - Page 10 - Expedition Portal

For parts I'm looking at:

• Current starter battery
• Optima Yellow top as secondary
• 2- 80 amp ANL fuses
• 1- 80 amp Solenoid ( This one maybe PAC PAC-500 500-Amp Battery Isolator Relay : Amazon.com : Automotive)
• Connectors
• PowerDrive RPPD1000 1000-Watt DC to AC Power Inverter
• 4 gauge cable

Attached is a basic diagram. Let me know if I'm missing anything, or if my diagram is incorrect.

 

[BrianSD_42]

Did you see the many dual battery threads in the 3rd Gen section?

Search will be necessary of course.

Also, YotaTech has some good threads on this topic.

 

[fourwd1]

I don't see anything isolating the second batt from the main battery.
They need to be isolated when the engine is Off.

 

[xcmountain80]

I don't see anything isolating the second batt from the main battery.
They need to be isolated when the engine is Off.

Ummm National Luna, Warn, the list goes on for dual battery isolators.

 

[Rocky5000100]

I don't see anything isolating the second batt from the main battery.
They need to be isolated when the engine is Off.

Well i do have the solenoid in there.

There seems to be a lot of people asking in thread whether they need a solenoid or an isolator. From what i read, an isolator IS a solenoid.

Ummm National Luna, Warn, the list goes on for dual battery isolators.

So basically where I have the solenoid drawn, you'd recommend I'd replace it with an isolator (a smart solenoid)? Or did I read those other threads wrong?

Thanks for the feedback everyone.

 

[fourwd1]

No. A typical battery isolator is 2 high current diodes connected back to back. It allows current from the alt to go to each battery, but each battery is isolated from the other ( a diode only conducts on one direction). Down side is a diode also has a 0.7V drop, so if your alts voltage out is only nominal (say 14V) only 13.3V reaches each battery, and that's insufficient for proper charging.
That's why I use a HD relay to isolate mine on my 83's dual batt setup.
But it can't be just any relay, in addition to the proper current capacity, it MUST be rated for continuous duty.
An while you do have a relay in your diagram, it's not isolating the batteries.