[question] I have some sealed lead-acid gel batteries that I ignorantly stored in a discharged state for a few years. Is there a way to tell if I can restore them to reasonable capacity with a pulse conditioning desulphator circuit instead of just giving up on them and buying new ones?

As a follow up, what are the signal characteristics I need to implement in a desulphator? (e.g., duty cycle, period/freq, peak/min voltage on signal, etc)

I'm considering using my function generator to pulse gate of a power FET so the battery sees a ~0v-14v squarish wave, but I couldn't find anybody who had done this before. I'm not sure if I should pulse the battery with 0-14v or with a small AC change on a bigger DC bias (e.g., 13vdc +1v peak square wave).

wikipedia section on lead-acid battery desulphation