BATTERY STATE OF CHARGE -
Without expensive metering equipment / hydrometers and specific battery information it is difficult to know what state your battery is in -
There is a quick method that is quite easy to test and inexpensive metering is used.
Allow your battery to rest. (No load or charge on it for > 1hr)
Use a multimeter or simple expanded scale voltmeter. Check the voltage of the battery and compare it to the graph below. Ideally you should never allow your battery to drop below 30 or 40 % S.O.C.)
Note: This is a guide only and will vary depending on battery type and chemistry.
The L.H. Side is 12V and the R.H. Side is 24V.