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Forum Index : Solar : Mate’s Off-Grid Install.
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Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1664 |
Hi All, A mate of mine has an 8kV off-grid system, being in for around 2 years. 2 inverters, the red thing for the batteries (Charger?), 24 batteries & I think 44 panels. I usually take a look at it on weekends we visit; checkout what the inverters say & look at the control display for the charger. Often hear the batteries bubbling like crazy & see charge voltages au at the 63V mark. Other value I notice, besides battery capacity is "SOH", referring to the batteries. Usually sitting around 86%. Does that mean they've degraded almost 15% in barely 2 years? Really doesn't sound normal to me, but for many reasons it's not something I buy into. Thoughts? Phil Edit:- The batteries look a bit like these (from memory). |
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Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1664 |
No Feedback at all? It's the 63V that really stands out to me. Surely that can't be right. |
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Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Yep 63V too high, he's cooking the batteries. I would find out more. Why is it set to those voltages, who set it up, what mode of charge controller is he using. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Hi Phil, We are happy to help but if you want us to help, you need to be willing to put a little intellectual effort into this. Perhaps there is something badly lost in translation, reading it on the screen, it kinda reads like you dont give a stuff. I cant speak for anyone else, I get hundreds of requests for free information every year from people with a poor attitude, after 20 years of this, I find it very tough, it really wears me down. if I have grossly misunderstood your post I am sorry. You haven't given us much detail about his setup, that makes it particularly hard. I would say ignore the SOH number for now, it could be true or false for any number of reasons, in the short term it is not really important, you can check and calibrate it later. to troubleshoot the high voltage you need to be there looking at things when the batteries are fully charged and the sun is decent and there are no other electrical loads, not early in the morning when they are naturally at a lower voltage from overnight use. A multimeter or two is needed to check voltages, a DC clamp meter would be very handy if you can find one. Clamp meters save a lot of time. it helps to be able to read some leds or a screen to see what the charge controller thinks it is doing and to have a list of what the expected voltages are for that particular mode. for wet lead acid cells I expect absorption phase to be set between 56-59 volts float between 54 and 54.5 volts resting (no charging or load) the battery should sit between 50 and 51 volts and equalization set to happen once every 25 days or maybe 2 months or so. it can run in this mode for days until certain time and voltage conditions are met. depending on the manufactures specs this could be anything from 59.5 volts to 66 volts or a cumulative two hours. we need to logically work through a list of possible causes/symptoms things like, charging system has been deliberately or accidentally bypassed somehow short circuited mosfets it is stuck in a continuous loop charging in equalization mode faulty temperature sensor faulty or damaged voltage or current sensors or maybe dodgy wiring incorrect settings software glitchs floating earth voltages, maybe from multiple ground points the most important thing is to focus on one thing at a time (preferably the simplest and cheapest to fix first) and be methodical until you are completely satisfied that is not the problem then move to the next thing to check. if you guys start tinkering and button pushing and throwing around ideas, you may as well pack up and go to the pub. cheers Yahoo Let us know what you come up with I'm confused, no wait... maybe I'm not... |
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Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1664 |
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