Well here is one for you ... couple weeks back went out halibut fishing...hit the trottle like I always do.. hmmm didnt seem to get up on plane as good as it normally does?? weird but hey rpm and speed all the same.
Plan for the day was to do the quick hali tide then go for salmon...
We finish halibut and went to start main.... CLICK CLICK WTF make sure its not in gear nope ..... hmmm start kicker get anchor up (barely) off we go on kicker ...So phone mechanic hey figures voltage issue.
So tells me put on battery 1 and try zip, ALL zip ,number 2 vrooom motor starts!!!! hhhmmm so we figure has to be either swith OR batterys right???
Now this is after WE spend weeks on re routing wires in winter and replace and bumping up wire guages checking the WHOLE system batteries were charged and loade tested prior.. etc etc etc
all weird codes and such coming from the guage ...was assure keep it going get back to dock...
So i head home to get tools etc and load tester etc.. put tester on one battery s do a load all good 13.4 go to next battery hit it 13.4 down to 6 and BAD hhhhmmmmm tested great 3 months prior and I always have trickle charger on all winter and make sure 2 times a year water levels are good.
So these were just coming up to 6 years old so I replaced with 31 series instead of a deep and a starting as mech said keep them both the same and bump up power so now I have 1200 CCA.
Moral of the story is with these new high end outboards and wanting max voltage I think ill be tossing out the batteries every 5 years just to be on safe side... And yes the start of the day when boat didnt take off as fast as normal it was the first stages of limp mode on main from weird voltage reading... hope this helps you guys as I leaned a valuable lesson..
Good luck wolf