I have tried "store bought" and kits. The kits perform MUCH better due to higher voltage level pings.
As far as success rates goes, it's about 50%. I've brought back batteries that sat dry for two years, but have also failed with batteries that are only two years old. It is kind of hit and miss.
The main things to remember when trying to bring back a battery are as follows:
- low amp charge, in the 1 to 2 amp range.
- "Dumb" chargers. Smart chargers can be damaged (or fooled) by the De-sulfators.
- Battery load tester. You want to Shock the battery one or two times during the process.
- Hydrometer, essential for verifying results.
- Patience. The process can take a week or two depending on the battery