I take back what I said, all I am finding is that Paralleling batt is fine. Sorry for the misinformation.
Back to the issue....I did find some thing that might help and I did not know. "If there is a .05 or more difference in the specific gravity reading
between the highest and lowest cell, you have a weak or dead cell(s). If you
are really lucky, applying an EQUALIZING charge may correct this condition."
"RECOMMENDED that you use a
temperature compensated hydrometer, which can be purchased, at an auto parts
"Most of the "defective" batteries that are returned to the manufacturer during
free placement warranty periods are good. This suggests that most sellers
of new batteries do not know how or take the time to properly load test or
"Another major cause of premature battery failure is sulfation. When batteries are stored discharged or stored fully charged for over three months without being recharged"
EQUALIZING charge will fix this. This info came from this great site... DEEP CYCLE BATTERY FAQ