Good news (maybe)!
Took the batteries out as I said, auto electrician charged them for two days, and they tested okay, 12.75 volts each and the rated Amp hours.
Put them back in the boat, put the switch to "both" and the motor
started just fine.
I let it run for 20 mins, checking the exhaust water
and put the multimeter on the terminals. Both batteries look to be getting 14 volts from the alternator
Turned the motor off, both batteries still showing 12.75 volts.
Left the boat for 48 hours and did the same as above, got the same results.
Looks like I might just have resurrected them. That's a tentative "woo hoo!"
Time will tell.
I'd happily just replace them if they're suspect, but with a new/old boat the shopping
list is very long, I have to dole out the $ sparingly.
And while my boat spending has been well inside the initial budget
, chiseling the teenager out of the nest has drained the coffers down to almost zero.
Ah parenthood; certainly the most expensive activity I've ever engaged in...
I'm moving the teen into her own apartment next week, them I'll move aboard. Getting rid of possessions as we speak.
Thanks for all the tips,