Over all Battery Bank Voltage Dropped
midijeep
Registered Users Posts: 102 ✭✭✭
I have a SMA Sunny Island with NiFe batteries @ 1.2v per battery . With the sunny island setup I had to use 38 batteries instead of 40. I have been running the batteries for about 3 years. At float the voltage per battery was 1.48v (and steady ~56.2 v for the entire battery bank at float) until 3 Days ago. Now, the battery bank voltage dropped and is steady at 55.07v (about 1 volt difference for the battery bank). I tested each battery with a multi-meter and each battery was 1.45v. so I didn't measure any batteries that where different from each other.
I am not sure if the sunny island decided to measure the voltage differently (it uses its own method of measuring voltage).
Should I worry about this steady 1 volt drop in the battery bank? Is there any other test I can do to determine if there is a problem with one of the batteries?
Comments
-
i'd recheck all the connections, and then load the battery /inverter with at least a 500w load. While loaded check the cell terminals of the far end of the cell you are checking, not on the terminal bolt, but the terminal bolt of the neighboring cell. you are looking for a poor connection which will have a higher voltage across it, than a good connection would.
Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister , -
Thanks Mike . I will give it a try later today.
-
mike95490 said:i'd recheck all the connections, and then load the battery /inverter with at least a 500w load. While loaded check the cell terminals of the far end of the cell you are checking, not on the terminal bolt, but the terminal bolt of the neighboring cell. you are looking for a poor connection which will have a higher voltage across it, than a good connection would.Check the connections and put a load on the bank. Everything seems to check out.I think the problem is with the SMA sunny Island. It doesn't like the NiFe battery composition. I have to use their NiCd preset on battery type because they do not have a choice for the NiFe composition.I think what happened is the boost charge charged the bank to about 80% and the SI used that calculation. What I did was a manual Boost charge and charged to 100%. Now the battery bank voltage at float is now at 56.6v, which is what I have been seeing since the beginning of connecting the NiFe battery bank. Thank for your help.
-
NiCad and NiFe setting are, for nearly all purposes, the same. Not sure what you are thinking is different between them
Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister , -
SMA uses a self-learning current-voltage algorithm model that adapts to the actual battery conditions within the battery type. It is more complex than using only one model e.g. a voltage model or current model or balancing the current model.
Categories
- All Categories
- 220 Forum & Website
- 128 Solar Forum News and Announcements
- 1.3K Solar News, Reviews, & Product Announcements
- 189 Solar Information links & sources, event announcements
- 886 Solar Product Reviews & Opinions
- 254 Solar Skeptics, Hype, & Scams Corner
- 22.3K Solar Electric Power, Wind Power & Balance of System
- 3.5K General Solar Power Topics
- 6.7K Solar Beginners Corner
- 1K PV Installers Forum - NEC, Wiring, Installation
- 2K Advanced Solar Electric Technical Forum
- 5.5K Off Grid Solar & Battery Systems
- 424 Caravan, Recreational Vehicle, and Marine Power Systems
- 1.1K Grid Tie and Grid Interactive Systems
- 651 Solar Water Pumping
- 815 Wind Power Generation
- 621 Energy Use & Conservation
- 608 Discussion Forums/Café
- 302 In the Weeds--Member's Choice
- 74 Construction
- 124 New Battery Technologies
- 108 Old Battery Tech Discussions
- 3.8K Solar News - Automatic Feed
- 3.8K Solar Energy News RSS Feed