Tried an Odyssey 680 in the back of my Citabria, worked fine. Moved it to the firewall, still worked fine. FWIW, I have another 680 in a Harley, works good, and a third in a high compression fuel-injected O-360 Pitts S-1 without an alternator that will do at least 5 hours of flying driving a transponder, comm radio, altimeter, tach, clock/g-meter, 10 hot starts over two/three days, and when I push it back into the hangar is at about 50%. 4 gauge cables.

CG in the Citabria is slightly out the front with just me in it and full fuel, and I have to add 10 lbs to the back of the baggage to be in. Tried flying it empty and out the front CG and it felt fine. I always carry gear in the back so a non-issue -not many guys will fly backcountry without gear. If you buy a new ACA with the extended baggage the battery is always on the firewall, and you work it out.

A1Skinner wrote:

Battson wrote:I would wonder whether the Oddessy has the power to crank from the extended baggage (original battery location). Mine is under the copilots seat, and it's not that energetic. That said, the cables are light.

I am keen to move it to the firewall, once its possible. Innovate, when paperwork allows.............

I'd be curious about that as well. On a Citabria with an 0-320 it works, but not a ton of extra cranking power. A big 470 might be a touch crank.

Easy to find out. Borrow an Odyssey battery (the J-16 is the tso'd one) and hook it up in place of the existing battery. See if it'll crank.

I suspect (guess) that the O-470 has fairly low compression. As I noted, they work fine back aft on a Husky, with O-360, which has higher compression than a 320. But, I don't know.

But, if his empty CG is still one inch from the forward limit......

MTV

skiermanmike wrote:

Nizina wrote:My mechanic installed a 10 pound lead weight in my tail cone.

Is this legal? I’d love to do this - would happily give up 10# in UL for a more reasonable empty CG.

My mechanic secured a field approval to add the weight to the tail cone.

Mine added the weight with just a logbook entry...

CParker wrote:.....I'm at 35.2" @ 1761 empty. That's with 10 lbs of lead in the tailcone already. I'll run some numbers to simulate and see where it comes up. I was at 34.1" before the lead. Forward limit is 33," if my memory serves me right. …...I'm definitely not an expert on any of this, and I don't intend to seem combative by any means, I'm just skeptical of the benefit of moving that weight forward and making an already nose heavy airplane even more so.....

Like most things, there are both pro's & cons to a forward CG.
The pro's are that it gives you more weight capacity for baggage.
The cons is that the airplane won't cruise quite as fast or stall quite as slow.
I suspect those are both pretty subtle differences.
In a taildragger, a fwd CG makes the airplane a bit less susceptible to a ground loop ,
but also makes it a little more susceptible to a nose-owner.

My own C180 is pretty fwd with the CG, but I don't see it as a problem.
I've never owned or even flown a 182,
what's the problem with it being "nose-heavy" as long as you're still within the approved envelope?
Trim the nose up and hold the yoke back as appropriate.

I've seen at least one field-approved flat-floored extended baggage with a cut-out for the standard battery box.
If you don't think you'd be happy with the CG moved forward,
maybe you can modify a store-bought flat extended baggage the same way.
Or else just get the old-school stepped-up ext baggage & live with it.
FWIW switching from the stock set-up to a firewall mounted Odyssey,
my airplane lost 20# & the CG moved fwd about 2.9".
Done before I owned it so I can't comment on the before-and-after flying characteristics.

hotrod180 wrote:
Like most things, there are both pro's & cons to a forward CG.
The pro's are that it gives you more weight capacity for baggage.
The cons is that the airplane won't cruise quite as fast or stall quite as slow.
I suspect those are both pretty subtle differences.
In a taildragger, a fwd CG makes the airplane a bit less susceptible to a ground loop ,
but also makes it a little more susceptible to a nose-owner.

My own C180 is pretty fwd with the CG, but I don't see it as a problem.
I've never owned or even flown a 182,
what's the problem with it being "nose-heavy" as long as you're still within the approved envelope?
Trim the nose up and hold the yoke back as appropriate.

My 180 is the same way and it is happy no matter where I have it loaded.

I did a little more investigation and see that you do have one of the "small tail" 182s of which I have never flown. They do have less elevator authority than those of us that are flying a trimmable horizontal stabilizer. Do you find yourself running out of nose up trim when landing?

I am in the process of moving my battery to the firewall. I have enjoyed reading this thread just to consider all of the options. I just removed a ton of old weight from the panel doing an avionics upgrade. The CG issue should be somewhat neutralized by the weight savings. I see everyone talking about the J16 Odyssey but the certified earth X battery is 9.6 lbs lighter. The difference makes the weight transfer even less bothersome from a CG perspective. Is there something I am missing with Lithium batteries? Seems like a no brainer to me to go with the Earth X.



Josh

Dog is my Copilot wrote: ... Is there something I am missing with Lithium batteries?... Josh

Dog is my Copilot wrote:I am in the process of moving my battery to the firewall. I have enjoyed reading this thread just to consider all of the options. I just removed a ton of old weight from the panel doing an avionics upgrade. The CG issue should be somewhat neutralized by the weight savings. I see everyone talking about the J16 Odyssey but the certified earth X battery is 9.6 lbs lighter. The difference makes the weight transfer even less bothersome from a CG perspective. Is there something I am missing with Lithium batteries? Seems like a no brainer to me to go with the Earth X.



Josh

Have you found an approval? As in STC?

Oh yeah, and lithium batteries still have some potential issues.

MTV

mtv wrote:Have you found an approval? As in STC?

Oh yeah, and lithium batteries still have some potential issues.

MTV

EarthX has a TSO battery now. Does that mean you can plop it in? Never been really clear about that with batteries.

Thanks again everyone, lots of excellent opinions to take into consideration. I'm a PPL with only two years on my certificate and about 200 hours TT, I've only ever flown my own 182 and a tiny tail 206 so my experience is very limited.

akaviator: yep, I do have the small tail 182. When empty I do have the trim maxed out and have to give it a pretty good tug to keep from landing flat, I don't lack upper body strength. I land power on. It seems that although I have the "small tail" 182, that's the case for most newer 182's anyways, the difference in total horizontal stabilizer surface area really isn't that huge as far as I can tell. I bought my current 182 last year not knowing there was a difference. I'm building time in this plane and enjoying it while I have it, learning about aircraft ownership, and will be looking to upgrade to a 206 in the next few years. Luckily, someone posted the exact serial numbers of 206 that were effected by the small tail so I can avoid them!

Zzz wrote:

mtv wrote:Have you found an approval? As in STC?

Oh yeah, and lithium batteries still have some potential issues.

MTV

EarthX has a TSO battery now. Does that mean you can plop it in? Never been really clear about that with batteries.

No, anSTC or field approval is going to be required. And lithium batteries have a history of overheating and potentially off gassing. The Earth X is supposedly safer, but I’ve heard of failures. If mounted in cockpit they recommend a vented box.

MTV

I think that’s a grey area, since your Pacer is a CAR3 airplane.

I’ve had my EarthX in the cabin since 2015. No issues, and saved a lot of weight over the odyssey it replaced.

I could probably taxi on the starter.

Have you worked that out on your W&B sheet to see if it really affects your plane enough? My look at this seemed that it wasn't worth the effort in my case.

Rod

I think a lot of the lithium battery issues have been solved. As far as I know, ever 406 ELT is powered by a lithium battery. It's funny because when buying a new battery for your ELT they can't be transported by air as they are dangerous goods, yet after install and certification we have to have them in our planes. I'd be more then happy to put a earth X in once the STC is out for my 206.

mtv wrote:
No, anSTC or field approval is going to be required.

Why is that considered a major alteration? TSO radios...swap em out with your favorite, they're just screwed in.

But a battery? Are specific batteries actually called out on the TCDS?

Zzz wrote:

mtv wrote:
No, anSTC or field approval is going to be required.

Why is that considered a major alteration? TSO radios...swap em out with your favorite, they're just screwed in.

But a battery? Are specific batteries actually called out on the TCDS?

Yep... the PA-22 calls out a Reeding 35 battery... problem is Reeding is no longer in business... If you look at Gill and Concord they have the -22 on their PMA for their batteries... FAA is pretty particular when it comes to electrical systems.. [emoji849]

Funny thing about your airplane Z... since the airworthiness and data plate were lost we had to have a DAR inspect it for conformity to the TC and all STC modifications... since the TC calls for the Reeding battery we wound up having to do a field approval for the GILL to get him to sign off on the paperwork to get the new stuff..

Brian


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Brian-StevesAircraft wrote:Funny thing about your airplane Z... since the airworthiness and data plate were lost we had to have a DAR inspect it for conformity to the TC and all STC modifications... since the TC calls for the Reeding battery we wound up having to do a field approval for the GILL to get him to sign off on the paperwork to get the new stuff..

Does the approval cover using the Gill as an anchor while on float ops?

What's funny is that I'm not shopping for a new battery, especially a $700 one. Just curious for Dog is my Co-pilot above.

But...I don't have a Gill