I use a size 27 just as for a car -----Original Message----- From: Dan <danb70341 at gmail.com> To: C320-List <C320-List at Catalina320.com> Sent: Mon, Jul 24, 2017 5:17 pm Subject: [C320-list] Starter battery's What cracking power is needed for a starting battery to start a 30 hp westerbeke? Thanks Sent from my iPhone