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    My Desulphator


    Dr Chaotica

    Posts : 35
    Join date : 2012-02-22

    My Desulphator

    Post  Dr Chaotica on Sun Jun 24, 2012 5:42 pm

    Desulphators, for rejuvenating a poor Lead Acid battery. They are also useful for nicads and NiMH cells.

    I've seen two basic desulphators that look useful. The small self powered box that works off the battery itself, and the mains powered version that plugs in.

    I've noticed that the self powered version needs one day, per pound of battery weight. That is far too long to wait, not to mention the cost of running the required charger.
    I, therefore, chose the mains powered version. You could always apply the self powered one afterwards, as a means of prevention of further sulphation.

    Some use a direct mains connected device, but in the interests of safety, I used a transformer at 25-0-25 volts. This gives the option of a hi/low setting, and In conjunction with the 4 capacitor values I use, that gives 8 possible charge rates.

    EDIT: I should say, except for the large motor cap, the caps are from old monitors and TV. 1 microfarad (105 marking) and up. X class, or from the high voltage section. Though X class are OK on mains and I've used them, I wouldn't risk any other type from salvaged monitors for direct mains, even if the voltage rating is sufficient. A mains line fuse of appropriate rating is absolutely essential......
    Stick to a transformer as shown here and save yourself the hassle and danger. It works just the same. No electrolytics allowed! Descriptive article: Class-X and Class-Y Capacitors

    A sulphated battery is the equivalent of a smaller capacity unit. Don't pump lots of Amps into a poor condition battery. If battery heating is a problem, use a lower value cap, or drop the applied voltage. Either will work. Start slow.
    A proper pulse device is less of an issue, but even then, in the case of a high output current capability such as direct drive, check the temperature isn't excessive as the process continues. Note that sealed lead acid may take a long time. They heat up easily due to the way they are constructed, so large currents are not realistic. The rubber vent caps should be removed. Water will be required.

    The clips are of course, the output.

    Last edited by Dr Chaotica on Wed Feb 07, 2018 5:16 pm; edited 8 times in total

    Dr Chaotica

    Posts : 35
    Join date : 2012-02-22

    Re: My Desulphator

    Post  Dr Chaotica on Sun Jun 24, 2012 5:43 pm

    I'll tell yer what. This thing is worth it's weight in gold where resuscitating NiCad drill packs is the goal. I changed some of the caps for mains voltage variety, for no reason other than they were more robust. I left the rest the same.

    Reluctant cells have to give up the fight in the end. Proper shorted ones can also be brute force cleared with it, but they're not worth the hassle.

      Current date/time is Tue Dec 18, 2018 2:58 pm