Thank you, retiredcarguy! I'm not a mechanic or electrician, so thanks for clearing up the amps/volts mistake on my part. I'm going to switch to the larger battery, but I'm going to take the top cover off first and check/clean the stator magnets and check it out too. I figure it can't hurt matters any. It's a 12 year old mower, so I'm sure it could use a good cleaning/sanding.... especially since the supposed "lawm mower mechanic" I got it from was running it without the regulator/rectifier in it, and just kept the battery charged so it would start and run for someone to test it out for a few minutes. I looked this mower up, and it cost right at $5000.00 new in 2002! It is a BEAST when it's running right though! I love the 54" mowing deck too.... it sure beats the 36" deck on the old Simplicity 4211H. It's a 1985 model, and runs like a kitten, except for needing the flat idler pulley replaced on the mower deck.
Peace,
Doug