Hello all, just bought an old lowes mtd with an 18 hp engine . When charged up the engine starts fine. But looses power on the battery within a couple of hours after shutting down. the amp gauge even shows a slight discharge to left of center after shutting off. When running, the amp gauge looks like it's charging showing about 1/8 of an inch to right of center. I got the mower for 30.00 dollars . had a new battery in it, so I figured the battery was worth the 30 bucks. I put a new carb kit in it and new plugs , replaced the dry rotted gas lines and cleaned out the gas tank and the mower started right up. smooth running machine when running . I have 2 new spindle shafts ordered for the deck. Any ideas where to start first on checking the battery discharge? Lowes number is 138-758-062 / 95198. Engine # is 422707-1251-01 code 940221. would appreciate any input that I could get. thanks