Multiple Battery Setup

You don't need to use an ideal diode part like LTC4358.
You can use a reverse-connected MOSFET as an ideal
diode for battery paralleling and/or reverse-polarity
protection. Here's an explanation:
http://www.geofex.com/article_folder.../mosswitch.htm

In my never-ending quest to make glider-pilot-proof
equipment, I'm using FDC610PZ in a new project.
I've recently noticed this part featured in some
LTC appnotes so apparently others think this a
suitable part for this application.

Choosing MOSFETs, watch the body diode max current on
inrush current (not specified for all MOSFETs).

Remember to keep the smoke inside the chips,
Best Regards, Dave "YO electric"