RV-8 Aft Battery Location Cable/Conduit

I've been able to find some conduit info but not exactly what my question is right now.

1. With an aft battery location should the cable be run in conduit?
2. For those of you that have run the aft location (using Odtyssey PC680 - seems to be the battery of choice), how long of a piece of cable have you used?

Thanks for your ongoing thoughts...

Doug
Builder in training

Mine's not run in conduit, but does have poly tubing over it for chafe protection and of course adle clamps. I do not know how long the cable ended up.

There seems to be a second aft location that I wish I had used. Mine is under the baggage shelf like most but I recently saw pictures of an Odyssey in a battery box in the next bay aft. I'm 240 lbs and my -8 has a constant speed prop so runs up near the front of the cg envelope when I fly solo. As light as the PC680 is, moving it back a couple more feet would probably help at least a little. I should do the math to see how much though.

Which position are you planning on using?

Aft Battery

Given:

Stock aft location with Van's mount.
Master contactor on the aft edge of the mount.
Starter contactor on the left vertical angle rivet line on the firewall per the firewall drawing.

Finished wire length is 126" from master contactor to starter contactor. This is Van's circuit P1 for the aft battery configuration, routed along the left side baggage area/floor ribs, through the spar center section and left side gear box (on the 8). Exits the firewall on the left edge (mine had a pre-punched hole, but locations are shown on the firewall and wiring drawings from Van's).

I crimped the battery terminal on first and fed the cable forward. #2 is very stiff and you'll need to rotate the cable to get the best orientation for the battery terminal connection. Adel clamps to secure in between the bulkheads. I crimped the starter contactor terminal after feeding through the firewall using a "Terminal Tool" clamped in my Workmate.

Good luck,
Mike

My aft-mounted Odyssey is in the standard van's location. I used #2 welding cable which is extremely flexible and has a very thick insulation layer, so didn't use conduit - just Adel Clamps for security and support. I probably bought fifteen feet of cable and got a funny look from the guy as to why I wanted something so short....

Paul

Same as Iron

I ran conduit to my rear mounted battery, but I ended up taking it out as the #2 wouldn't feed down through it. I used ultra flex #2awg welding wire too and I plan to just use adel clamps. One thing I considered was if the wire did get hot for any reason (it shouldn't), the conduit will just be another source of more smoke and melted plastic. I used 14' but it was barely enough. I ran it down the right side under the floor boards and then up through the right gear tower across the z brace and fwd to the firewall.

http://www.mykitlog.com/owens

I have been trying to source the #2 welding cable mentioned above. It seems there is both 2 AWG and 2/0 welding cable. The specifications are different for them. The welding supply places I have called don't know what 2 AWG cable is and don't stock the 2/0 cable. Amazon has both, so which one is the correct cable for our use?

Thanks

I got my best deals on US made welding cable on eBay.

Carl

That's a good source, thanks. I'm guessing I should order 2 AWG, not 2/0, but would like confirmation.

Steve N. said:

That's a good source, thanks. I'm guessing I should order 2 AWG, not 2/0, but would like confirmation.

Click to expand...

Go into the Knuckles book and look up the cross section area. Then pick the cable that best matches.

I mounted one PC-625 in a modified stock battery mount in the per plans aft location, and the second PC-625 in a modified Van's mount in the forward baggage well. I used #4 welding cable from the aft master solenoid to the output of the forward battery solenoid.. the forward battery feeds the forward solenoid with the same #4 cable. The now combined output goes to the starter solenoid and starter with a #2 cable.

I like the PC-625 over the 680 as it has a few more Amphrs,a few more CCA, and is a little bit lighter. The form factor works better for me as well.

I mounted the batteries to achieve my W&B targets (IO-360M1B, standard Hartzell CS BA prop and Grove gear).

Carl

I did all the work to put the battery in the tail, and then when the earthx super light batteries came out, I figured I could save about 20 pounds by installing their smallest battery on the firewall. No long fat cables, easier inspections, great starting power.

http://www.rv8.ch/battery-holder/

Just another option.