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.