Well thanks for the info. I have been thinking about getting a load tester as they can be bought at princess auto for about $25. They just don't do 6v so it seemed to defeat the purpose. I have tried a couple of digital multimeter's, but they did not seem able to determine enough consistency to be usefull. A hydrometer is an option.
I have not drained and refilled yet, I am just curious about the process. I am inquiring if anyone out there has personal experience with it.
Using only distilled water because of mineral deposits is somthing I am familiar with as my cigar humidors operate on the same principal.
Mixing mulitiple brands of unkown length was/is a gamble. They are all 6v as the 8d's are not attached to the house bank. They may have hit the wall and are time to be recycled. They seem to charge up, they just don't hold a full charge for too long. They drop down to 12.8 volts after a full charge after a day or so. The battery specialists (the suppliers @ the RV dealership I worked briefly at) had said that this was still a good resting charge for older 6v and were still usable. I can still get 4 - 5 days with out charging, so I am not tossing them yet. I am looking at ways to restore them.
I have never deep cycled them below 11.2 volts, is this a problem?