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Using RV-10 Battery Angle Plate for Second Batt

Ender

Active Member
Looking at the RV-10, it has very similar structure around the elevator turnbuckle. One of the differences is that the plate of that structure is shorter on the RV-14. On the RV-10, the extra real estate is used for the battery.

Has anyone put this plate (the RV-10 one) in to use for a backup battery mounting location?

If one put a lithium batt back there, there wouldn't be much of a hit to C.G.
 
On the RV-14 I don't know that it's a great location for a backup battery. Perhaps if you use a lithium maybe, it wouldn't be so bad. But, it's pretty far aft to be putting a lot of extra weight. If you add a sizeable battery there, you're going to find it much easier to run into aft C.G. conditions.

I mounted mine under the seats, which puts it very near center for C.G. For aerobatics, you'll want that C.G. as far ahead as practical, so consider areas that are as far forward as you can think of.
 
Thanks Tim. I was planning lithium. I liked it out of the cab in case it starts to smoke. What type did you put under your seats?

I think it only (potentially) works if you get one of the <2 lb ones. I think the heaviest I saw was 4 ish.

Side question. I?m a pretty light guy. Where does the CG in your plane sit with full tanks. Does it tend fwd or aft? I noticed the vans trike had a ballast box in the back, so I was wondering if it was normally a bit fwd.
 
Mine comes in pretty forward on the CG Range until you start loading it up. I'm not a light guy though so I change the CG more than you will. It's the aerobatic CG range that I have to be careful to fit in. After looking over my charts for loadings, I'm guessing you'll be just fine, if you keep the battery light like you're thinking. If you were talking an Odyssey or something, I would say don't do it, but lithium would work. Keep in mind that there really is not any significant protection from smoke in the tail, so if something burns up in there, those fumes have many paths to the cockpit. That bulkhead is definitely not airtight, and even if you fill in the corrugations there are plenty of other places where that smoke will quickly make it to the cockpit.

I stuck with lead acid, and mounted under the pilots seats by making my own little battery trays during the build. Not saying it's great, but it's a safe battery and not a horrible location, and has worked out well.
 
Here is how one RV-14A builder added a second PC-680 in his plane.

Carl

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BD65-DA11-DBF3-4-D02-A96-E-5-CB0-AB984304.jpg
 
2nd battery

Yes, right where Carl's pic shows. I would not want to add any more weight in the tail than needed. The airframe comes out a little aft heavy by design it seems. I even thought of moving my ELT further forward but realized that was a dumb idea. I have 2 LiPo's (Earth X) on the firewall and seems to be a good combination. My prop is composite and of course that does not help but prelim W&B look ok.
 
Just for sake of discussion, I'll ask the "why a second battery" question. I have two alternators, a backup battery for avionics, another backup battery on the G5. My system draws about 13-14 amps (18-19 with pitot heat on), and I've had zero problems starting. Seems to me that the added complexity if you place the second battery on its own buss would add minimal extra safety (backup alternator seems a better option to me), and if on the same buss is as vulnerable to current drain as the first battery. I did upgrade the starter (to Skytec NL) as many mentioned the standard starter can be a bit wimpy.
 
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Hopefully a B plan will not be needed

A second alternator would take precedent over a second battery in my limited view and a second battery does add slightly more complexity (It's already a fairly complex air frame) but it was far better to design the system for 2 batteries right from the beginning in my view. I wanted to go with Earth X and I've seen LiPo's take an unwanted dump using them in my sailplane and giant scale radio control air frames. The Earth X BMS system looks superior to anything I've dealt with in the past but sometimes you can't help stupid. (Ask me I know) Below is a recent post of a air frame with an issue and possibly a second battery (On a separate bus) could be useful.

'So I?m stranded in Connecticut with a bad Earth X battery. If I can?t work out something quickly with Earth X I need a B-plan. I need a battery that I can toss in and go, no retrofitting work on the ramp with 32 degree temps. So does the Odyssey 925 fit in the standard -10 battery tray. What?s the difference between the PC 925 vs 925L. Any other battery recommendations for the 10 with a stock single battery tray Thanks all."
 
Just for sake of discussion, I'll ask the "why a second battery" question. I have two alternators, a backup battery for avionics, another backup battery on the G5. My system draws about 13-14 amps (18-19 with pitot heat on), and I've had zero problems starting. Seems to me that the added complexity if you place the second battery on its own buss would add minimal extra safety (backup alternator seems a better option to me), and if on the same buss is as vulnerable to current drain as the first battery. I did upgrade the starter (to Skytec NL) as many mentioned the standard starter can be a bit wimpy.

Turner - PM me your phone number and I will offer my thoughts on why two batteries and one alternator provide the basis for a far more robust design as compared to two alternators and one battery.

Sorry for the thread drift.

Carl
 
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