My BX 23S is 2-1/2 years old with the original battery...and from the beginning I never felt the battery had enough umph.....When the tractor is not in use, I have it on a trickle charger....I don't use the tractor all that often, & sits inside. After sitting for a period of time I find that it cranks over quite a bit before firing and the battery feels like its getting lazy....My question: What is the best replacement battery? Not looking to pinch pennies, but want a battery with some kick to it....