Call Dane Forsberg at SMA. Very knowledgeable. He helped me recently go through all the settings on my 8kw SI system.
Sent from my iPhone On Oct 14, 2012, at 9:41 PM, mac Lewis <maclew...@gmail.com> wrote: Hi wrenches, About 2 months ago, we installed an off-grid Sunny Island System. Here are the specs: 8.82 kW PV SunnyBoy 8000 2 x Sunny Island 5048 Inverters 2490 Ahr SolarOne HUP batteries at 48V 30 kW Cummins Propane Generator We are having an issue that I am having a hard time figuring out. We are getting sagging battery voltage, and can't seem to keep the battery voltage and specific gravity where we want it. In addition, I have equalized these batteries 4 times this past month, and the specific gravity gets to about 1.25-1.26 maximum. I have slowly eased up the boost, absorb and equalize voltage setpoints, to try to get the battery a better charge, but it doesn't seem to help. The Sunny Islands don't seem to have any issue getting these batteries up to the equalization voltage, or any of the other voltage set points. I have checked for loose connections, all look good here. The SOC monitor on the Sunny Island master, calculates that we are staying between 70-95% SOC on a daily basis, and yet the battery voltage has dropped below readable level a few times(I believe this is below 41V). I equalized at 62 V for 4 hours and had the same result of nonimpressive sepecific gravity and saggy voltage under small load. After we leave from equalizing the batteries, things seem to be OK for a while and then we start having issues again. We are tripping a 250A battery breaker, and getting low voltage errors on the SI, yet SOC looks good. Right now I have the set points programmed per SolarOnes advice as: Boost Voltage= 2.46 V/cell Full Charge Voltage = 2.46V/cell Equalize Voltage = 2.54V/cell Thanks in advance for any ideas that you may have. -- Mac Lewis * "Yo solo sé que no sé nada." -Sócrates * _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
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