Originally Posted by mpolli

These devices are mainly for sulphate prevention. They can only remove minimal sulphate once it has built up. All it does is charge up to some voltage (in my case 13.5) and then let the battery float down .1V and then repeat. I have one on some batteries I have for standby power. I have not had it long enough to know (check back in 5 or 10 years...). However, it is only for batteries kept on long term storage. A starting battery in normal use in a car doesn't need it. And if you had a battery sitting around for a long time it probably wont help it.

Mike