Battery Testing

I did some testing yesterday.
Left the charger on the battery overnite.
It started right up.
Pulled the + cable off the battery.
It kept running just fine.
Put the + cable back on and shut it down.
Took the + cable off again.
With the key off I touched the + cable to the battery.
No little sparks, so that means no short somewhere.
Turned the key on and tryed again.
This time little sparks as it should.
So the alternator is good and there is no short with the key off.

I got one of those eye-dropper specific gravity testers for the battery.
I tested 3 of the cells.
4 balls floating means 100%. 3 balls means 75%.
In 2 of the cells I had 3 balls floating and the 4th was trying.
So I got 75% out of two cells. I didn"t check the other 3.

Does that 75% mean:
1.) the battery is 75% charged
or
2.) the battery still has 75% of its life left.

If #1, would leaving it on the charger longer help it any.

This is a deep cycle marine battery we use for our trolling motor.
I needed a battery last fall and just grabbed that one cause it was handy. I will be getting a new battery for it this spring.

Anything else I should check?

Thanks.

Pooh Bear

DON'T unhook a battery cable to see if will keep running, supposedly indicating the alternator is charging.

Pulling off a battery cable with a generator system can cause higher than normal system voltage, which is tough on the breaker points, and pulling off a battery cable on a system with an alternator is cautioned against by most alternator manufacturers, because voltage spikes may damage the alternator or (solid-state) voltage regulator>

Using a voltmeter is a better, safer plan.

Thanks.

Pooh Bear