Yes, that is an aspect to this but not the root cause of the problem I am having.
The product manager explained that because the LG battery has an internal DC to DC converter, when it switches between charging and discharging, there is a appx 3 second loss of power when in backup mode. He described how one setup could be 2xLG Resu and 1x BYD as the BYD maintains constant voltage and no “lag.” Still, my own personal LG in a StorEdge system has absolutely no issue like this so I’m trying to figure out why this is a challenge in SMA but not SolarEdge. But back to my main problem, which is charging of the battery in backup mode, from the PV inverter. I am still awaiting his promised email, but he discussed setting country code to Ca Rule 21 to soften the charging points. He said setpoints for when to cease recharging (to prevents too high charging) is field adjustable but I find the SMA interface to be a complex, PhD level of complexity without much installer-level explanation. He also said if any of the three batteries were at this no-charge setpoint, this might cease PV charging so I’ll check that and if that the case, I’ll turn oof high SoC batteries and try to bring all up to common level. I sure hope this is not the case because that would be a serious software gap. I’ll share more as I get more info or learn more in the field. Scot Arey From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of Jerry Shafer Sent: Friday, July 10, 2020 6:01 PM To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Subject: Re: [RE-wrenches] SMA Sunny Storage AC-coupled with SB6.0 won't recharge LG Resu batteries during backup ops Scott, Wrenches We have had systems with the SMA storage but we have used the BYD and have had no problems so far with recharge and operations all as expected, it may be an issue with LG programming and the SMA not communicating properly JUerry On Fri, Jul 10, 2020 at 2:57 PM <scot.a...@solarcentex.com <mailto:scot.a...@solarcentex.com> > wrote: We have a design with Sunny Storage 6.0 inverter, SB 6.0 PV inverter, the SMA Automatic Backup Unit, and three LG Resu batteries. Works like a charm during normal grid ops but when it goes into backup ops, the Sunny Storage increases frequency to between 60.6 with blips up to 61 hertz, resulting in the PV inverter throttling back from 5,000+ watts to between 1,300 to 345 watts. The result is that the batteries do not recharge from the PV during backup mode, even when SoC is less than half capacity. This also means the max power through the ABU to the “whole house backup” is the 6,000 watts from the Sunny Storage plus the (very) retarded power output of the SB PV inverter. SMA tech support just said, “that is normal, the LG Battery is the culprit and does not charge from PV in this setup.” I was stunned because why else would I buy this ABU coupling setup…Anybody have any ideas? I’m hoping the Sunny Storage freq shifting ramp-up parameters can be adjusted so that PV inverter operations continue when the battery is at a less than full SoC. _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org <mailto: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 <http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org <http://www.members.re-wrenches.org>
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