BlueSky 2000e Question

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bdannels
bdannels Registered Users Posts: 9
Hello:

In my off grid cabin, all seems to be working OK at end of the day. The panels putting out 4.8, BUT CC is blinking away at 14.2. When I check the 4 batteries at the terminals the voltage is 13.17 to 13.25? I have a inverter connected also with a volt meter, it reads 13.03. Also have a kill-a watt. Plugged into it that, it reads 12.60 When I check the amps at the cc panel terminals I get 11.7
Not sure why the CC is indicating full charged batteries?

Thanks for your time
Bill

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,442 admin
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    Re: BlueSky 2000e Question

    Welcome to the forum Bill.

    You need to check connections and diameter of your copper cabling. You need short/heavy copper wire from the battery bank to everything else. With 12 volts, much more than 0.5 volt of drop is too much for a reliable system.

    For the connection from the charge controller to the battery bank, you should have around 0.05 to 0.10 volts maximum drop so the charge controller has an "accurate" voltage measurement of the battery bank. Any more voltage drop, and the charge controller will cut back on charging current early because it thinks the battery bank is full. Short/heavy copper cable from the charge controller to the battery bus is the only answer here.

    There are other issues too... Many "simple" PWM controllers have a very short "absorb" charging phase... Ideally, for batteries that are getting deeply cycled, you want the "absorb" phase to be held at ~14.4 volts (depending on battery type) for 2-4 hours at a minimum to get your batteries fully charged. Many popular solar charge controllers will only hold absorb for ~1 hour.

    Do you have flooded cell batteries where you can measure the Specific Gravity of each cell--A good hydrometer (and thermometer) is the gold standard for understanding the state of charge of your battery bank.

    So, can you tell us a bit about your system... Solar array (Watts, type/model of panels, Vmp/Imp of your panels/array), charge controller brand/model (link to controller may be handy), AWG or mm^2 of cabling and distance from charge controller to battery bank.

    Amp*Hour rating of battery bank (type, number of batteries, series/parallel connections).

    I believe in a "balanced" system design... Battery bank designed to support your loads, and the Solar array/backup charging source(s) designed to keep your battery bank happy.

    If the design has problems and/or you do not keep up on battery maintenance, you will probably have problems.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: BlueSky 2000e Question

    Welcome to the forum Bill.

    Let's see if I have this straight: the Charge Controller thinks the Voltage is at 14.4, which would be a low Absorb setting, but when you check the Voltage at the batteries it is 13.25?

    This would indicate three possibilities:

    1). The wire between the charge controller and batteries is too small or otherwise has too much resistance.

    2). The Voltmeter you are using is inaccurate (check for low/dead battery).

    3). Something is wrong with the charge controller. Let's hope it's not that.

    How are you checking the Amps? The only way you can do that is to put the meter in series with the wiring, and if the panel output truly is 11.7 that would be a bad idea as most of these small meters can only handle 10 Amps.

    Could you give us a few more details about your system such as panel specifications and wire sizes?
  • bdannels
    bdannels Registered Users Posts: 9
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    Re: BlueSky 2000e Question

    That is what is going on!

    > 1). The wire between the charge controller and batteries is too small or otherwise has too much resistance.

    I am not sure what to small is, I have a piece about 10' of HD outdoor stranded extent ion cord. I am guessing it's at least 12 gauge.

    > 2). The Voltmeter you are using is inaccurate (check for low/dead battery).

    I have 2 different meters, both say about the same thing.

    3). Something is wrong with the charge controller. Let's hope it's not that.

    Let's not go there just yet.

    > How are you checking the Amps?

    If you are QUICK you can read over 10 Amps, before it gets too hot!:blush:

    My camp is in FL., hundred's of 60'+ pine trees. I have 2-195 17volts on the roof.
    They are FLAT on the roof at this point in time. 10 gauge feed to the CC probably, 25 feet. Also have 2- 140's on the ground 25 feet of 8 gauge. The most output I have ever seen from them is about 12-15 amps. Lots of shade. Right now it's 3:15, 2 panels are in full sun CC is blinking away at 14+ Inverter volts says 12.96? 4-12 volt 125. AmpHrs. RV/Marine, less than ideal, but only get here about once a month for the weekend. The batteries are about a year old. I did check them with a hydrometer a few months back. I don't remember what they were, but they were all very close.

    1500 watt inverter, probably 10 feet from the batteries using #6 gauge, I think.

    As backup I have a Yamaha 3000iseb remote start, that I love dearly! Coffee microwave and well pump/shower!!
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
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    Re: BlueSky 2000e Question
    This would indicate three possibilities:

    1). The wire between the charge controller and batteries is too small or otherwise has too much resistance.

    2). The Voltmeter you are using is inaccurate (check for low/dead battery).

    3). Something is wrong with the charge controller. Let's hope it's not that.

    There might be a fourth possibility... The OP is in florida and may have warm batteries. If he has temp compensation, the controller may be (quite appropriately) reducing the voltage. I don't know much about blue sky controllers... but... some controllers display their "nominal" set point voltages, but their actual output is a temperature compensated voltage.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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    Re: BlueSky 2000e Question

    Yes the blue sky 2000e can be temp compensated but there is a dip switch needing set, as well as you will need the RTS...

    What did the inverter manufacturer say about the wire size needed? Mine was a MINIMUM of #2 gauge for 1500 watts for up to 6 feet.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
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    Re: BlueSky 2000e Question

    Considering the OP said he is using a piece of "Extension Cord", I would venture to guess that the wiring is way undersized; perhaps in more than one place and/or loose connections?

    Also the OP mentioned "lots of shade". Even a small amount of shade on a panel will reduce the output of it signifigantly; although that is likely not directly related to the different voltages he is seeing.

    Where in FL is your camp located?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: BlueSky 2000e Question

    Things that factor into Voltage drop:
    Initial Voltage, length of wire run, size of wire, current on wire.

    Two 195 Watt panels? They would typically be 35 Vmp 5.5 Imp. Together on a 12 Volt system those two alone should put out 25 Amps with a good MPPT controller. Some controllers, such as the Blue Sky, are not going to work well with 35 Volts in and 12 Volts out; they limit the current. If the angle isn't right they will not produce full current.

    Your 140 Watt panels are likely to be "12 Volt" meaning Vmp 17-18 and Imp around 8. How have you got those wired in relation to the other panels? They should be in series forming a 36-ish Vmp string which is then parallel to the 195 Watt panels. If they don't all get the same sun you can't expect maximum power from the array. With 670 Watts total and equal insolation on the panels a good MPPT controller should give you roughly 43 Amps peak current.

    This extension cord from the controller to the batteries could be a real problem. 12 AWG cord is big and expensive; most of these cords (ironically labeled "heavy duty" due to their insulation not their current carrying capacity) are only 16 AWG. Across 10' of 16 AWG with 12 Volts and 10 Amps you get almost a full Volt drop.

    Then there's that inverter wiring: 6 AWG is only good for about 60 Amps, which @ 12 Volts is 720 Watts. If you were to run the inverter at full load this would fry. To say nothing of the V-drop even operated at it's capacity: over 4%. Really it should have 0 AWG minimum on it, and with 12 Volt systems the larger the better.

    I think you have some rewiring to do, and possibly a new charge controller to buy.
  • bdannels
    bdannels Registered Users Posts: 9
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    Re: BlueSky 2000e Question

    River Ranch, close to Frost proof.
  • bdannels
    bdannels Registered Users Posts: 9
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    Re: BlueSky 2000e Question

    Appreciate the response from you and others.
    I did some more checking this am before packing up. Findings listed below.
    FIRST All panels are 17 volts. Two parallel strings 12 volt each. The reference to the inverter was just for the meter reading.
    Not saying the wiring should not being larger, it's really a separate problem.

    When I measure the CC bat. output at the CC bat. Terminals (early morning) I get 13.64 then I checked it at the bat. After disconnecting from bat. and I get 13.62 volts. Seems OK, wire size may be under size, but not the real problem. IMHO

    I disconnected 3 of the batteries (only 1 connected) AND removed the load.
    Battery at the terminal is 13.4. The CC is blinking away (saying charged)14.2? The amp. Out put says 5.6. When I keep my meter on the battery terminals over a 4 or 5 minute time span it reads (blinks) 13.20-13.21 maybe 30 seconds it says 13.21-13.22 Then again it's 13.22-13.23. so it's still charging. I just checked again, maybe 5 minutes later and it's 13.37

    Then sun behind a tree (partial shade) CC NOW indicates charging (not blinking)
    Output says 3.2 amps. Battery volts down to 13.15.

    Clearly the CC output is holding up the battery volts, without it, volts drop. That all seems normal to me.
    What I don't understand is: If the CC says the battery is charged and the CC output shows 5+ amps is that 5+ amps still going to the battery?
    In checking the panel output at the CC terminals I can read 11+ amps..
    The CC is showing on the amp output meter 5+, so it's stopping about 1/2 the amps. With the battery at a little over 13. Volts. I did set the dip switches when I installed the temp. Sensor. Never did see any difference with or without the sensor.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: BlueSky 2000e Question

    Do you have the specs/make/model on those panels? a 195 Watt "12 Volt" panel would be unusual. Possibly Evergreen? At any rate the total panels should be able to "max out" that controller if they are all getting good sun.

    Voltage drop becomes a greater problem as current goes up; under low current flow (such as early morning when the panels aren't producing full power) it will not be so obvious.

    The Voltage you are reading is not by any means capable of recharging the batteries; you should be hitting 14+ Volts in order to achieve proper Absorb stage. The controller seems to think it is, while the batteries are remaining low (about -1V in fact). So you have to check things piece by piece, starting with measuring the Isc on each panel to make sure there is enough power to actually charge anything.

    You've got four batteries in parallel. That's potentially 500 Amp hours @ 12 Volts. If this charging system has only been producing 10 Amps current at most and/or less than 14.4 Volts at the battery and this has been going on for a long time it is very likely the batteries have been chronically undercharged and are now suffering from sulphation. Not good. Do you have a plug-in battery charger you can put on and see if you can boost any of them up to over 14 Volts? You will also want to check the 'at rest' Voltage by leaving them disconnected from everything overnight. In the morning you want to see something around 12.7 Volts.
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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    Re: BlueSky 2000e Question

    from your first posts you have 4 12 V panels right?

    Sorry to say this, but that controller can only handle 20 amps Isc input, so less than 2 panels @ 195W.

    Did you read the manual carefully? on page 5 you will find a warning box, starting on the 4th line

    Do not connect a PV array capable of delivering greater than 20 amps of short circuit current ISC at STC
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
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    Re: BlueSky 2000e Question
    bdannels wrote: »
    River Ranch, close to Frost proof.

    I know RR well :) I'm in Suburban Estates. Kinda the same type of place except RR is too "controlled" for me -- the main reason I wanted to go off-grid :)

    I am still leaning towards undersized wiring or a bad connection somewhere.
    With a 12v system even losing .5 volts due to wire size is a LOT.
    But that just made me think of something...are all of your batteries the SAME brand/make and same age?

    My neighbor had 4 T105's and 2 generic ones of the same AH in the same bank together and for some reason the 2 generic ones would charge faster (and get a lot hotter), and since they were at the end of the string the rest of the batteries suffered from undercharging for many months until I happened to notice the problem when I was over there a week or so ago. We took those 2 out of the bank and now things are great (well, IF the batteries end up surviving).

    Just some ideas.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • bdannels
    bdannels Registered Users Posts: 9
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    Re: BlueSky 2000e Question

    No they are not all the same,BUT on my last test I only had 1 battery connected to the cc and it did the same thing?
  • bdannels
    bdannels Registered Users Posts: 9
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    Re: BlueSky 2000e Question

    Thyis is all I have on the 2 195's I am back at home now. (2 x SUN Solar Panel 195 Watts 18.30 Vmp (SV-X-195-LV)

    >Do you have a plug-in battery charger you can put on and see if you can boost any of them up to over 14 Volts?
    My camp is actually a 26' trailler 2005 it has a charger built in that is on when the Gen. is running. I will check the Bat. volts when the Gen is running when I get bact there.

    I did also mention in a previous post the CC is doing the same thing even with 1 battery connected?

    Appreciate your response
    Bill
  • bdannels
    bdannels Registered Users Posts: 9
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    Re: BlueSky 2000e Question

    Westbranch:

    I am with you. There is so much shade where I am at, one would wonder why anyone would put up solar panels.
    Plus the 2 on my roof are almost FLAT! I have never seen more than 15 amps going TO my panels.

    I am only there abou 2 days a month.

    Appreciate your input
    Bill