I found the Battery Saver on Ebay for around 90 bucks. I thought I would give it a try instead of spending 600 on new batteries. To my supprise, there was a noticable difference within a couple of days. You have to charge the batteries at least once a week, because the Battery Saver is on all of the time. 

I tried it on a second cart to make sure that I was not just imaginging this change. It happend agian. The batteries on the second cart were revived in a couple of days. From what I undersand this gaget will work as long as you do not have any dead cells. Be sure to check the specific gravity of all of the battery cells to verify no dead cells prior to purchasing. It was well worth the money.