Hello everyone. I am fairly new to, but very interested in, electronics and how they work. All my life I have enjoyed taking machines apart and being able to understand how and why they work but have always lacked an in depth knowledge. I would also like to learn how to design and build my own. I am going to use this as an excuse to introduce myself to building more complex circuits. In the past I have made a few basic LED circuits connected to power supplies in order to light my aquarium and have learned a surprising amount from them such as how the slightest change in voltage can have drastic affects on wavelength, power consumption and to a lesser extend brightness. I have a 36v battery pack containing 3 12v gel lead acid batteries (for my purpose I must use gel batteries) and before decided to go down the desulfating path I considered buying these as a replacement: http://cgi.ebay.co.uk/NP7-12-12v-7A...rElectronics_Batteries_SM&hash=item19bf71fec3 They are practically identical apart from the fact that they are made by a different company and mine are 8AH not 7. I am not sure how relevant most of this is but I am attempting to be thorough. The batteries I am desulfating (inside the battery pack) are each producing about 12.8v after being fully charged and the voltage they produce is in no way a problem but the low amps per hour are. I have looked online and although a few companies sell 12 and 24 volt desulfators and desulfator kits I have found no 36v ones in the UK. Not to mention being unable to find a trace of a schematic for a 36v one. Most of the schematics I have found use a 555 chip which appears to be designed to create timed pulses which does appear to be what a desulfator does anyway. I am sure the 12v desulfator design can be easily modified to the 36v design but I simply do not know how and have had no luck in finding out how online. 1) How would I go about designing and building my 36v desulfator? 2) Would it be safe to build one into an extension cable between the charger and battery? 3) Does anybody know any good parts sellers in the UK apart from the ones on Ebay? 4) Does anybody have first hand experience with any negative effects caused by desulfators? Thank you