I am installing Dynon AP servos in my 2001 built RV-8. Before I start on the Pitch servo I need to relocate or replace the aft battery that is currently mounted forward of the bell crank right where the servo needs to go. Welcome any tips on the install and / or alternate locations for a second battery. Do I even need a second battery? I/O 360 with dual Pmags. Future instrument panel will be Skyview HDX with avionics backup battery. Are there any RV8's out there with AP installed and can share pics?
Van's Air Force
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Where should I re-locate my Aft battery?
- Thread starter Aquaman!
- Start date
As for the question to if you need one that‘s something really only you can answer. Personally I don’t think you need one for a VFR airplane with dual PMAGs as the PMAGs have their own internal power source. Even if you fly IFR and you have a glass panel I would probably prefer the backup batteries sold by Garmin or Dynon as they are better integrated which I think is a safer solution e.g. they do regular battery tests and warn you when it’s time to replace the Battery.
Oliver
Thank you for the picture worth a thousand words! Nice install
Carl Froehlich
Well Known Member
Keep in mind battery location in the RV-8(A) is also a design choice for W&B. Even with a parrallel valve IO-360, adding the nice Hartzell BA CS prop will drive you toward a battery mounted in the aft location. In my RV-8 I have a PC-625 mounted in the aft location, and a second PC-625 mounted in the forward baggage well. This set up provided a nice W&B, and the power distribution design eliminated the need for any of the various backup batteries people are putting in their planes.
Side note - I find the PC-625 superior to the PC-680 as it has more CCA, more AMP-HRs and is slightly lighter than the PC-680. For me the form factor is also easier to work with.
Carl
If you use a very small earthx battery, you can put it on the FW and save the battery weight and the cable weight. I have the "heavy" hartzell, with a parallel valve io-360 and Grove airfoil gear, and my W&B is fine even with an empty baggage area. I usually keep my tool bag in the back anyway, but that's much more useful load than a heavy battery.
True if you use lead acid batteries. EarthX batteries have no noticeable impact on weight and balance. Frankly the long cable you need weighs nearly as much as the battery…. .
More fun to put a smoke tank back there for weight and balance…. .
Oliver
Not sure who's instructions you mean, but you can put your battery anywhere you want - front of the FW, behind the FW, or under the rear baggage area. I found it to be much simpler and lighter to mount it FWF, upper right side. I can touch the battery easily when checking the oil, which could be useful if it needs a charge, or to confirm the connections are tight.
Dynons for the AP pitch servo
