Can't start the boat

[awthacker]

I am having ongoing issues. A few weeks ago, I topped off all the cells on both batteries, which were all low, then plugged in the charger. After charging, I still can't turn the boat over, so I'm not sure if it's the battieries or the starter, which sounds a little rough.

Today I test the starting battery with the $5 tester that sucks the acid out of the cells, and it looks good on the tester. So I put the battery back in and try to crank it today. Starter doesn't want to turn and I notice smoke on the positive battery terminal and it's hot to the touch. Picture of the smoke attached.

Any ideas?

BTW, the charger I use is the onboard Guest charger, so I'm not sure how well it does at recharging a low battery. But it does test good on the hydronic meter and show 12V. Any way for me to determine how many amps it offers?

Thank,
Aaron