[wingnut60]

I believe that you can replace the older converter with a higher capacity one--I recommend the Progressive Dynamics 9200 series that have the intelligent battery minder (Charge Wizard) built in. As with most items, mfgs ususally add the smallest capacity of anything (least cost) that fits the specs--tires are the most talked about of this situation.
However, changing the brands/size might be limited by space available where the converter is located.
Hope you have located the problem.
Joe