---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 01/21/19: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:46 PM - Re: Re: Battery (H. Ivan Haecker) ________________________________ Message 1 _____________________________________ Time: 05:46:18 PM PST US From: "H. Ivan Haecker" Subject: Re: AeroElectric-List: Re: Battery I learned today from EarthX that they are ok with using a small solar charger to charge their batteries, as long as it will NEVER exceed 14.6 volts. Their emphasis, not mine.They also stated that many solar units commonly are 15 volts or more and therefore not to be used with their batteries. Ivan Haecker On Sun, Jan 20, 2019 at 11:10 AM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > >All for a couple of dollars delivered. > > ebay item 183558004137 > > It looks like this particular one works with a solar input of 6 to 18 > volts. There are definitely some cheap viable options available for the > Do-It-Yourselfer. Even more are available for Lithium batteries. > > > A little digging reveals some concerns about this charger. The IC used on > the module is the Consonance CN3767 (datasheet here ( > http://www.consonance-elec.com/pdf/datasheet/DSE-CN3767.pdf)). > While > it *is* a true MPPT charger (a rarity on eBay at this price point), it's > probably not going to function as you would like, for a couple of reasons. > > First, the seller's claim that the module can accept solar panel inputs > between 6 and 18V, while true, is misleading. The CN3767 uses a buck > topology, not buck-boost. This means that it can only *reduce* the input > voltage. Any time the solar panel's output falls below the battery voltage > minus a diode drop, the battery will not be charged at all. So to charge a > battery that's sitting at 12V, the minimum solar panel output will be > >12.7V. > > Second, the photos of the module show that the maximum power point voltage > (Vmpp) is set lower than it should be for a low-power > > > Good put Eric. I would like to qualify my > earlier assertions about 'solar chargers' > in that my comments targeted the generic > solar arrays some with built in isolation > diodes and NO active electronics. I've got > a couple of panels laying around here that > I was considering for use on farm equipment > that sits idle for long periods of time . . . > generally allowing battery(ies) to self-destruct. > Usually very EXPENSIVE batteries I might add. > > Popular devices like this > > > * https://tinyurl.com/y7x2wbfu * which > is better than nothing but too small > to be a serious charger . . . and if it were > larger like this one > > https://tinyurl.com/y9zy4zjs > > perhaps too big to be allowed un-controlled > access to the battery in maintenance. > > I have one of those '18w' devices . . . and > it's really closer to a 10 watt. Yeah, it > will put 1+ amps into an SVLA battery in > full, direct sunlight . . . but output falls > of markedly with changes in sun angle and > clouds. > > To be sure, solar arrays CAN be adapted to > charging and maintaining batteries but > they require the addition of electronic > 'smarts' to competently craft a set-it-and- > forget-it maintenance system. > > The eBay item cited is interesting. I've > ordered a couple. I'll team one up with > a pair of my not-quite-18w panels and > put a data acquisition system on it. > > MEASUREMENT will tell the story. Thanks > for the heads-up! > > > Bob . . . > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.