Yes, Solar inverters, for example SMA uses the PV-arrays "constant current" output to fint the Maximum power point of the source,
They sink the source deep down in voltage to find the optimum current*voltage , To find the load at the moment that produces the panels Arrays "max" output Power. , So, that is not a good thing if we use a solar inverter and put a big strong battery as the "PV-array"-source and sinks it to "zero" volt to find the sources max currents after the max voltag :-) "BAM!" ? http://www.aurora-energy.com/iv-curve-of-a-solar-panel/ http://www.pveducation.org/pvcdrom/solar-cell-operation/iv-curve Im not good at designing electronics, but maybe some of you can design a "currentsource" that mimics the PV array? To put between the inverter and battery, And also give it a maximum output current... 4000 amp non regulated input current ( ..the BAM!) is not good for my solar inverter when it hunts down the I V "curve" to find the max, I believe that they do not have a fast max current protection inside them at all, probably they just uses the max current output from the array. / John ---------------------------------------- > Date: Sun, 21 Dec 2014 17:00:28 -0800 > To: [email protected] > Subject: Re: [EVDL] OT: batteries for solar PV off-grid > From: [email protected] > > Many solar inverters can be (user) configured to do different types of > optimization, so they can be adapted to different solar panels and even > different inputs (wind, battery bank) but I did not see which inverter > you use, so it is not possible to say if *your* inverter can handle > batteries as a source. Some (cheap) PV optimizers short-circuit the > panel when they do not need the power from it. Obviously that is a bad > idea when using a battery as the source instead of a solar panel. > > Cor van de Water > Chief Scientist > Proxim Wireless Corporation http://www.proxim.com > Email: [email protected] Private: http://www.cvandewater.info > Skype: cor_van_de_water Tel: +1 408 383 7626 > > > -----Original Message----- > From: EV [mailto:[email protected]] On Behalf Of Ben Goren via > EV > Sent: Sunday, December 21, 2014 1:08 PM > To: John Lussmyer; Electric Vehicle Discussion List > Subject: Re: [EVDL] OT: batteries for solar PV off-grid > > On Dec 21, 2014, at 1:53 PM, John Lussmyer via EV <[email protected]> > wrote: > >> Actually, bad assumption. Many/Most PV Inverters don't like being fed > from batteries. Throws off their attempts to find the Max Power Point. > > I didn't know that. Would it matter that the batteries would mostly be > feeding the inverter only when the panels aren't producing? > >> Also, PV inverters are more expensive than "regular" inverters. > > Well, the system is already in place and has been for a few years. I've > already got the inverter, in other words. Seems like, unless it's likely > to do bad things, it's better to spend no money on a less-than-perfect > but still-usable solution, than to spend more money to get a better > version of something I already have that'll work. > > So...is it a matter of this not being the ideal way to design the system > if starting from scratch, or of this being something that's workable at > all? > > Or...are "regular" inverters so inexpensive relative to the total > battery system cost that I'm being silly for not considering one as part > of the cost of the system...? > > b& > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: signature.asc > Type: application/pgp-signature > Size: 801 bytes > Desc: Message signed with OpenPGP using GPGMail > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141221/e332 > 5647/attachment.pgp> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
