Daniel, Quote "I have to plan out a new protective setup to try to ensure that if the temperatures drop and the battery bank hits LVD, that the array cannot just charge the battery back up on it's own."
Quote “...But adding controls to allow discharge, but not charge is likely a bit too much,…” Quote “…best to just isolate the battery bank if below 32-35F..." As I mentioned, these features are already built into the Li EMS system of 2 brands that we sell and likely other brands. No need to reinvent it. Larry Crutcher Starlight Solar Power Systems On Feb 28, 2018, at 9:15 AM, Daniel Young <dyo...@dovetailsolar.com> wrote: These issues are not lost on me for sure. I have to plan out a new protective setup to try to ensure that if the temperatures drop and the battery bank hits LVD, that the array cannot just charge the battery back up on it's own. Possibly some sort of temperature dependent relay or shunt trip breaker on the battery bank to ensure that below 35F the battery must be manually warmed to resume operation, or the system waits until the battery warms on it's own before allowing the CC's or even a generator to charge them. My understanding is that the lithium's can go below freezing easily, but they just cannot be charged when below freezing. They can sit down to -5F if not being charged, they can even be under discharge down to that in some cases. But adding controls to allow discharge, but not charge is likely a bit too much, best to just isolate the battery bank if below 32-35F in my opinion, which is what I plan to try to accomplish. Ideally someone is there to watch the batteries, but that simply is not an option. And the client is not likely to want a new AGM bank. But they will have to decide between the pro's and con's. All I can do is give them the info, and the choice. With Regards, Daniel Young, NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
