Wouldn't it be better to have a 3.9V zener across the battery? Unless thay have leakage current when off?
If I'm going to put it across the panel then I'd probably want a 4.3V zener, and then drop ~0.4V between the panel and the battery? The result doesn't have to be precisely 3.9V on the battery, just somewhere in that neighborhood. -Pete. June 2, 2020 11:17 AM, "Lee Hart via EV" <[email protected]> wrote: > Peter VanDerWal via EV wrote: > >> Correction, My panels have 2x12 cells. ~5.5V at VMP, ~7V VOC >> >> Now that I think about it, I don't think just using diodes will work. The >> VMP and VOC are two far >> about to make it practical. > > How about a zener diode across the panel to limit its peak voltage? Then a > series diode (needed > anyway) between it and the Li cell? > > The zener would need a high enough power rating to "dump" the output current > of the PV panel in > full sun. 5w zeners are easy to get; a 5.1v 5w zener could safely shunt about > 500ma (de-rated 2:1 > for long life). > > You'd have to play with parts to find the right combination. > > Lee Hart > > -- When something bad happens, you have three choices: You can let it > define you; let it destroy you; or you can let it strengthen you. > -- Theodor Seuss Geisel > -- > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
