Wings Forum

deshaffer · Joined: 14 Jan 2008 Posts: 1

The aircraft being discussed is a Just Aircraft, model Escapade, with a Rotax 912 ULS engine.

I have located the battery behind the luggage aft wall per the factory instructions.

Questions:

1. What AWG size battery cable should be used?
2. Should I run the negative cable from the battery to engine ground point? Or ground the frame locally?
3. Currently, I am using number 6 AWG battery cable wire.

Thanks
DES

rgmullins · Joined: 04 Sep 2007 Posts: 79 Location: Cincinnati

Welcome to the group!!!

I am also using 6 AWG cable. I grounded to the frame back by the battery. I figured why add the extra weight?

scubarider · Joined: 24 Dec 2006 Posts: 287 Location: Cleveland, GA

I just ran both of my wires to the front and tied in most of my grounding to one point on the frame. Probably didn't need to do that but didn't know any better. :?
D

rgmullins · Joined: 04 Sep 2007 Posts: 79 Location: Cincinnati

John sent me a private email (not sure why it was private...) but he said Just Air had told him he needed to run 2 separate cables and they had to be 4 AWG. What have others ran for the 912?

b1x4nqb · Joined: 14 Aug 2006 Posts: 176 Location: Orwigsburg, PA

I know for that Dave ran 1 and used the frame as a ground source. Not sure on his gauge. I just picked up some 2 gauge locally at an auto parts store. I wasn't looking for that thick of stuff but I had a hard time finding it locally. With shipping costs I figured my price couldn't be beat. The weight is a little more but then again, if I skip a lunch I could easily offset the difference.

Paul, PA

DaveU · Joined: 16 Aug 2006 Posts: 160

I used 4 ga welding cable, it has a flexible copper core. I ran a positive wire from the battery to the master relay, right by the battery, and then on to the firewall for the starting selenoid. I grounded the battery to the fuselage on the tab closest to the battery that the rear baggage panel mounts to. The then used the center motor mount lug (not used for the mount when the little wheel is in the back) to connect to the ground lug on the starter.

Cubs have been wired in this manner since the 30's. I do not have any problems with this method. I checked it at the annual and there is no issue with corrosion.

Dave

KevinC · Posted: Tue Jan 15, 2008 10:48 pm Post subject: Battery cables

Troy recommended that I run two from the battery to the firewall - so that is what I did. Dave is probably right, though - electrically speaking.

fwiw

Kevin

John S · Joined: 25 Dec 2007 Posts: 8 Location: hockessin, Delaware

Thanks for all your replies, guys. Kevin, what AWG size cables are you running? As I understand it from your posting, you'll be running a positive and a negative cable from the battery up to a grounding point on the firewall.

Also, should all my grounds come to that same point on the firewall?

Thanks again for all your help. This is a great forum.

John S.

rgmullins: I was too new to the list to understand how to make a reply. The private reply was all I could find, so I went for it. I think I've got the regular system figured out now. Thanks for your help.