[Lars]

(brown) Santa showed up a couple of weeks ago bearing big boxes containing my GRT EFIS and other goodies. Among them a GRT backup battery. I am now trying to figure out where to install it in my slider -7. If anyone has installed one of these I'd be much obliged if you have a photo or two to share.

Thanks!

 

[tommylewis]

my choice

Since no one replied to you, I will tell you what I did. When I built my RV7a, GRT did not have a battery backup option but I added a backup battery. My choice was to mount a bracket that I made from 3/4 inch angle stock to the back side of the subpanel in front of the pilot. To remove the backup battery for servicing, I remove the GRT screen in front of the pilot, unscrew the two screws on the front side of the subpanel which hold the backup battery and bracket. When I replaced the battery at 3 years, I also added a wire to enable charging the backup battery. This design and location has worked well in my RV7a for the last 4 years. As I do a panel upgrade to an RV10 this winter, I am going to install the same design.

 

[Lars]

Since no one replied to you, I will tell you what I did. When I built my RV7a, GRT did not have a battery backup option but I added a backup battery. My choice was to mount a bracket that I made from 3/4 inch angle stock to the back side of the subpanel in front of the pilot. To remove the backup battery for servicing, I remove the GRT screen in front of the pilot, unscrew the two screws on the front side of the subpanel which hold the backup battery and bracket. When I replaced the battery at 3 years, I also added a wire to enable charging the backup battery. This design and location has worked well in my RV7a for the last 4 years. As I do a panel upgrade to an RV10 this winter, I am going to install the same design.

Thanks, Tom-

I seem to have a knack for asking about things that are either really obscure or really boring

The GRT backup battery is in an aluminum case. It's long and skinny and sort of on the heavy side, but it does have a charging circuit built in, and an output for monitoring the charge state. I tried holding it up to the back side of the subpanel in the location you described, and it looks like I may be able to make that work. I got the big GRT display, so access will be easy with it removed.