"We test- - - -not guess!" Sun Electric Co. put that slogan on all their test equipment over 60 years ago and it's still just as right today. Take the battery out and have a parts store such as O'Reilly's or Advance Auto Parts test it. Chances are it won't pass the load test, but give it a chance for a blindfiold and a last cigarette before you call the firing squad to attention. Most likely, the cable clamps where they meet the battery have corroded and all they need is a good scrubbing with a battery post and clamp cleaner- - - -that tool costs a small fraction of what a battery does.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!