Double Battery Design Ideas
 

Gentlemen,
I'm finishing the tail feathers and have reached a point where I could use some advice. Could some of you share your designs for a double battery framework?

Thanks in advance.

Are you asking for electrical system architecture or battery box construction?

The battery box construction. . .

Double PC680 Battery Box
 

This is what I did for two PC680 batteries in my RV7A.
http://www.flickr.com/photos/94930805@N04/8647230516/
It is reinforced on the cabin side with aluminum angle similar to what is called out in the plans, but added between the exisiting angles where the new battery box bolts through the firewall and into the new angle. The floor of the box is .090 aluminum with lightening holes in it. I designed it with +6/-3 g loading on the weight of 2 PC680s in mind. The batteries shown are there for spacing only.

I'm still plainly confused by inserting images :mad:

Mike, sent you a PM.

Here are some photo's of my set-up. I just built a new tray using some leftover aluminum sheet and I used aluminum angles to stiffen it up.

We used a PC680 as the aux battery and a PC925L as the main battery since it fit in the existing tray. The black box is a charging relay manufactured by Blue Seas Technology P/N 7610. It keeps the aux battery charged as long as the main battery voltage is over 13.5 volts.

i really like a double battery design
 

had same in my last Mooney and now in my rv7a. batteries are a common source of ignition for fires during a crash. while a 20+ g design might not be practical, I urge you to think about crash loads and impact on big writes as you design your installation.

Double battery upfront
 

Is there anybody that considered to install a second battery (only for avionics and EFII system) up front? I have a second generator taking the place of my vacuum pump location. If os, where, how large and what electrical installation was used?

If you plan on hauling four with baggage like we fly, then one 925 in the back and a 680 on the firewall will work better for your CG especially if you have a lighter prop.