• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

PC-680 Battery Mount

rv6ator

MEMBER
Sherman, CT
20220827_165407.jpg

Van's PC-680 Battery box mounted on aft firewall, Javron widebody.
 

Attachments

  • 20220827_165407.jpg
    20220827_165407.jpg
    91.1 KB · Views: 122
What exhaust are you running. Looks like it would be a bitch to get out and hot with a stock muffler. DENNY
 
Looks like the lower bolt/screw heads holding the case are on the engine side. If you have a stock muffler or Hot Rod not much room at that point and firewall gets hot. Cable lugs are right next to firewall, would be easier to work with if lugs are closer to pilot. I have done some welding working with tight space batteries is the past so it just catches my eye.
DENNY
 
If you swapped the nut plates to the firewall and had a 3 part boot cowl it would not be that bad for a battery change. DENNY
 
Hopefully the front opens for easy battery removal and space has been made to install an insulation blanket under the battery and box. I'd turn the terminals to the cockpit side, too.
 
..........and depending on the panel install, or defrost, etc. access may be an issue.
 
Battery has enough clearance to slide out, I plan on using the AN4 bolt on the lower r/h side for battery ground and engine ground on firewall side.
Also a pic of my Andair fuel valve relocation to lower l/h kick panel.20220914_152146.jpg20220914_152858.jpg20220914_151500-1.jpg20220914_151326.jpg20220914_153642.jpg
 

Attachments

  • 20220914_152146.jpg
    20220914_152146.jpg
    102.6 KB · Views: 86
  • 20220914_152858.jpg
    20220914_152858.jpg
    67.2 KB · Views: 89
  • 20220914_151500-1.jpg
    20220914_151500-1.jpg
    46.3 KB · Views: 82
  • 20220914_151326.jpg
    20220914_151326.jpg
    216.5 KB · Views: 83
  • 20220914_153642.jpg
    20220914_153642.jpg
    184.1 KB · Views: 101
Curious about a couple of things. Why did you put the box on the firewall instead of the tubing? The firewall is not structural and the tubing is structure. Maybe safer to drop the battery down into the box instead of sliding it in from the side? Think about the battery retainer becoming loose.

And the fuel flow transducer is placed between the gascolator and the carb/fuel control as per the installation instructions. This gives it a bit more protection from contamination.

Go ahead. I'm wearing my cup.

Web
 
Battery box attached to 3 welded standoffs, it's going nowhere. Hopefully fuel tank strainer will block any large debris. Transducer has quite a large opening and is actually an optical sensor.I can always move it FWF, but we'llsee how it works.20220826_173033.jpg
 

Attachments

  • 20220826_173033.jpg
    20220826_173033.jpg
    124.8 KB · Views: 79
I like the Andair install. Very tidy. And I can’t imagine your cube will work any differently there than forward. Thanks for the battery install pics. Nice work!
 
According to the install instructions that transducer still has a rotor inside it. That's what will catch any trash coming down the lines. Something to think about.

Web
 
What engine will you use? Do expect acceleration to be so great as to test a firewall mounted battery? Deceleration high enough to challenge any firewall mount is going to ruin your day anyway. A guy has to decide when enough is enough. Totally acceptable once out of the clutches of the FAA’s silly book of rules.
 

Perhaps I didn't understand this picture. It appears to show the flow sensor in the fuel line between the valve and the gascolator and with the sensor outlet lower than the inlet. If that is a proper interpretation then it does not seem conform with the installation instructions which say:

"The Gold Cube FT-90 should NOT be installed with the wires pointing DOWN (the best situation is with wires pointing UP). Also, the fuel line on the outlet port should not drop down after exiting the transducer. Both of these configurations can trap bubbles in the transducer causing jumpy readings. The inlet port, outlet port and flow direction are marked on the top of the Gold Cube FT-90."

I have a "red cube" in my aircraft so I have taken an interest in their reliability and consistency of calibration at different flow rates.
 
20220914_153642.jpg
Perhaps I didn't understand this picture. It appears to show the flow sensor in the fuel line between the valve and the gascolator and with the sensor outlet lower than the inlet. If that is a proper interpretation then it does not seem conform with the installation instructions which say:

"The Gold Cube FT-90 should NOT be installed with the wires pointing DOWN (the best situation is with wires pointing UP). Also, the fuel line on the outlet port should not drop down after exiting the transducer. Both of these configurations can trap bubbles in the transducer causing jumpy readings. The inlet port, outlet port and flow direction are marked on the top of the Gold Cube FT-90."

I have a "red cube" in my aircraft so I have taken an interest in their reliability and consistency of calibration at different flow rates.
Actually the wires ARE exiting from the top of the cube, the excess wire is tucked down through one of the mounting holes temporarilly to keep it out of the way. Once again, if this location proves inadequate then I may relocate to FWF. Aft of firewall installation leaves one less source of FWF leaks and having to fire protect the cube. Any installation cannot guarantee the outlet will remain above or below the transducer during any given aircraft attitude. I have seen these cubes mounted vertically with no loss of accuracy. Phase 1 flight testing will determine the airworthiness/accuracy of the installation.
 

Attachments

  • 20220914_153642.jpg
    20220914_153642.jpg
    357.7 KB · Views: 56
Last edited:
The wires must point up AND the outlet port should not drop down.

All brands of fuel flowsystems that I've worked with say that this is to keep air bubbles out of the transducer.

Web
 
Not just the outlet port. Fuel lines from Cube to carb or servo should all run uphill from the outlet. Easier done when closer to the carb or servo but not impossible from the location shown.
 
Mounting the battery on firewall moves the CG forward so why do it? Piper put it aft which helps, especially on floats where you can get CG too far forward when light. I guess everyone’s mission is different.
 
I am running a light weight Catto so hopefully that will offset the battery move. I like not having to run a ba/ery cable to the back seat. Forrward C.G is easy to adjust with survival gear in the aft baggage, aft C.G you're kind of stuck with.
 
The PC680 is a run out spare for fitting purposes. Probably will gok with an EarthX when the time comes.
However I have had good luck with the PC680 in the RV7, lasted 5 years and was still working fine, figured I would replace it just the same and they are only $125.
 
So there you go. Weight's a non-issue. I still can't get over how light my EarthXs are when I go to pick one up. But alas, I just replaced my 180's battery with another Odyssey. It's hard to go wrong with either one.
 
Smart of EarthX to make a battery that will physically replace a PC680.
.
Ex battery is 79mm wide; PC680 is 76mm wide. Will not replace the 680.. too wide. The only direct pc680 sized lithium replacement comes from Aerolithium.
And they also have a front loader box for a lot less than $89 !
Sounds like your drinking too much earthx koolaid...
 
Back
Top