Unfortunately, I am not talking about my beer gut...

I fly a CH601XL with a Jabiru 3300 in front.

I was having problems with my 25.5 lbs. battery going dead too frequently, so I switched it out for a 13.5 lbs. Odyssey 680 last weekend.

WOW! what a difference 12 lbs. makes forward of the firewall. I immediately noticed a difference on take off. Less trim was needed for the plane to fly off the ground. It just felt lighter on climb out.

I can now set and trim for straight and level flight at 2100 RPMs. With the heavier battery I could not get any lower than 2300 at full nose up trim for straight and level flight.

The plane no longer feels nose heavy on final and in the flare. The control stick is not as heavy in the flare. My first landing this evening I was able to better control the float after round off and keep the nose wheel up longer after main gear touch down. All important for future soft field landings.

I know this sounds a bit unusual but I really like the feel of the airplane much better now.

All along some of us wondered about that big ol' battery up front.

I did the math on the W & B and it does move the CG aft a bit, but I had a lot of room to move before. I plan to re-weigh the plane and re-do my W & B for the POH.

Views: 133


You need to be a member of Zenith Aircraft Builders and Flyers to add comments!

Join Zenith Aircraft Builders and Flyers

Comment by John Cange on March 13, 2010 at 4:14pm
Hmmmm, and I was just thinking of taking the 680 out and replacing it with the PC925. My battery can leave me stranded if I taxi across the field to get gas, and if I dare use any strobes or landing lights, while in the traffic pattern that little battery will be too low restart the engine until it's charged. I always leave a trickle charge on it. I hate putting that much extra weight in the front, but I'd like to know that my battery has enough juice to power what I need while on the ground.
Comment by Brad DeMeo on September 9, 2009 at 6:55pm
So far, the Odyssey battery is working great. I flew 2.5 hours this last weekend, taxied across the airport to weigh the plane, had 4 starts, and saw no weakness in the charge or recharge. Volts and Amps were where they should be and cold crank start was quick. I have a bone to pick with Concorde Battery Co.
Comment by Jake Reyna on September 3, 2009 at 7:41am
Brad, I forgot to thank you for the inspiration to write a blog. I've had trouble with my Odyssey battery and another local builder had the same. Basically it was sitting too long connected to the electrical system. I had some standard auto trickle chargers, but eventually the battery wouldn't hold the charge.

Thinking I had to buy another battery, I decided to read the Manuals at Odyssey. Auto chargers work, but chargers built for AGM batteries are better. Odyssey has also done testing on restoring batteries that no longer hold a charge. Following their recommendations, I was able to save the battery. I connected the charger to the battery yesterday and was in Storage mode in less than 15 minutes, the battery had been sitting for at least 2 months.

Seems that some V-Twin motorcycles have the same problem charging an Odyssey. The recommendation is to connect to a charger and to be operated continuously while not in use.

I didn't realize you were based out of Santa Rosa. I won't be ready for Cloverdale this year, but should see you there next Spring.
Comment by Brad DeMeo on September 2, 2009 at 7:04pm
Roger, Those of us with Jabiru's have a 25 amp alternator that really does not produce full charge until the RPM's are up around 1800. One day I taxied to the run up area and everything went dead because I had too much draw with all the lights, radios and instruments on. Now I taxi with only the radios, EMS and safety lights on until I am ready for take off. Then its "lights, camera, action."
Comment by Brad DeMeo on September 2, 2009 at 7:00pm
Hah! Maybe we can get Dan Marino to build a Zodiac XL.

My CG limits are 300 to 450. My wife and I are small folks, so too much weight up front can impact the CG significantly for us. It is one of the reasons I chose the Jabiru over the Continental or Corvair. I have one of the earlier XL's so the angle of incidence on teh wing is lower than the new XL's, I believe. This can make it feel "nose" heavy, too...especially on take off. We are under 300 lbs. in the seats soakin' wet. When we had 30 lbs. of baggage behind us on our way up to Oregon the airplane flew very well with full tanks and both of us aboard.

I do remember your CG issues. I'm glad you found a solution. I think mine are resolved as well.

Happy and safe flying!!
Comment by Roger Lambert on September 2, 2009 at 11:30am
I've got two years and 200 hours on the Odyssey PC680 battery. Its worked well and always holds charge. We used a regular auto battery charger on it the two times I left the master switch on accidentally. The charging system charges at 14.5(approximately) volts off a 30 amp alternator. Its in a 601xl in front of the firewall on the lower left side without additional cooling and behind a Continental 0-200A.

New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...


Weather Maps

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.

Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits

Zenith Apparel from EAA:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Golden Eagle Aviation

Pianosa Flying Farm

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2020   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service