I would take the batteries to a place that can do a load test on the
batteries with a real load. Autozone, Pepboys and walmart should be
able to load test.

The batteries are placed inside a compartment, and this is kind of hard
to pull them out especially in cold weather. This is the reason why I
leave them in the boat instead of moving them indoor. I will pass on
this one unless my preliminary load test indicates that the batteries
may be dying.

A starter running with no load is really no load on a battery.

If I understand this correctly, the starter still needs to move around
the "thing" inside the cylinders even when I am just doing a load test
on the batteries (by turning off the kill switch to prevent ignition).
Shouldn't this be enough as a load?

For $20.00 you can buy your own load tester.
http://www.harborfreight.com/cpi/cta...emnumber=90636

Sound great. I intend to order a 1/2" wide blade screwdriver from
Harbor Freight today anyway.

By the way, I looked around in the batteries area last night. And I
found these:

o The connection near the voltmeter is kind of rusty. I have a
feeling that this may have created enough resistance to cause the
voltmeter to show a low reading.

o The charger is setup correctly for lead acid wet batteries that I am
using.

o The charger is able to charge the batteries really good (the
batteries were up to 13.37-volt right after charging, and 12.95-volt
one hour after charging). The reason why I got a lower reading
(12.99-volt) right after charging on the day before might have
something to do with the fact that I disconnected the recharger right
after the full-charge light turns ON. Seem like the charger is still
trying to "top-off" the batteries after it has turned ON the
full-charge light. This explains the reason why I saw a lower reading
(12.99-volt) right after fully charged the batteries on the day before.
In other words, this was an "operator error", and the charger was/is
OK, and the batteries are likely to be OK also. I am happy about this.

Jay Chan