I didn't try it personally , but my friend has and I saw it. Conclusion is that success with Desulfators depends on type(brand?) of Desulfator and type (and condition) of battery. He tried different batts with two of these things and for some batts it worked great , for others almost nothing (mind you , he didn't knew how old is particular battery or what is the condition of it). Some people from other forum has mixed feelings and impressions about it too. There are schematics on the net for building one and that was tried too, with various levels of success. It all comes to how lucky you are and how much $$ you want to spend for device. As a rule , cheap Desulfators work on car (flooded) batteries fine (if battery isn't ruined totally) and for SLA's with unknown outcome. And yes , I know that this post doesn't help at all , but that is all I know so far about it.