When fooling around with the XW computer software, I had noticed references to Peukert's exponent. This made me suspect that an integrated amp-hour meter was at least on somebody's XW radar screen.
An "intelligent algorithm" as Mark mentions below is not necessarily inferior to the counting of electrons via an amp-hour meter...it all depends on how "intelligent" the voltage based algorithm is. Tri-metric style percentage readouts can only be right if the battery is in good health, and here's another problem: Since the Tri-metric requires the battery efficiency & amp hour capacity to be manually set by the user, as those values change the meter really needs to be re-programmed, but how does one determine good numbers for this season? Especially when the battery begins to develop middle aged health problems, battery voltage re-asserts as an important state of charge determinant...maybe that's why (most to) all of the generator automation schemes use voltage/time factors instead of amp-hours. After all, it's crummy low battery voltage which will cause the inverter to shut down, regardless of what the percentage "fuel gauge" meter says. If a true amp-hour meter were ever integrated into the XW system, my big "wish list" item is similar to what Todd mentions below. Whenever the charge controller goes into float, that should signal the battery fuel gauge to reset to 100% (and the battery efficiency should be calculated & updated at that point). Blue Sky does this with their 3024i controller/meter combination. Those who are familiar with other brands please chime in to advise if anyone else does this. If simiilar function could integrate with the XW system, the float/reset trigger could come not from just a solar charge controller, but from any networked charging source. Thinking way outside the box, now...if battery real ampacity could also be calculated and updated...or if it could just be recorded so a human could look at the ah delivery data and manually make the change...that's a feature that I think nobody has so far. Mick Abraham, Proprietor www.abrahamsolar.com Voice: 970-731-4675 ---------- Original Message ----------- From: "Mark Edmunds" <[EMAIL PROTECTED]> To: <RE-wrenches@lists.re-wrenches.org> Sent: Mon, 28 Jul 2008 10:03:40 -0700 Subject: Re: [RE-wrenches] Battery charging with XW series equipment > Hi Todd, Wrenches, > The XW does use an intelligent algorithm taking input data from all charging > devices and the battery voltage to come with an estimate for the battery > state of charge. This is pretty good, but agree an amp-hour meter would be a > nice addition to get even more accuracy on this. Needless to say this has > been looked at closely in house and all the hooks were designed in to add a > system A-h meter moduleÂ…we need to figure out when and how we can best add > this. No definite answer yet, but all input appreciated. > Cheers, > Mark > Mark Edmunds > Xantrex Technology Inc. > > I wish they would address the question I asked about why they neglected to > include an amp hour meter that communicates with their charge controller on a > battery based system. > > Todd ------- End of Original Message -------
_______________________________________________ List sponsored by Home Power magazine RE-wrenches@lists.re-wrenches.org http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org List rules & etiquette: http://www.re-wrenches.org/etiquette.htm Check out participant bios: www.mrsharkey.com/wrenches/
