Battery issues

The509The509 Registered Users Posts: 22 ✭✭
First post so don't slam me :)

I bought 8 Trojan L16 last year before the fires. They sat for 6 months before I hooked them up. Strung at 24 volts Xantrex MPPT and 3 X 250 watt panels. I live at around 3400 feet in WA and have great sun. Each day they seem fully charged but when I wake I'm showing output of like 23 volts. The only load I have on them is a couple cigerette lighter outlets charging iPhones.

Is that normal?
«1

Comments

  • BB.BB. Super Moderators Posts: 26,872 admin
    In general, flooded cell lead acid deep cycle batteries need to be recharged (~24 hours on a standard AC battery charger) at least once a month minimum.

    If you leave them sit for ~6 months without charging, the batteries go below ~75% state of charge (after one month) and start sulfating faster and faster. After 6 months of no charging--There is a good chance that these batteries have very little of the original capacity (sulfating is when the "fluffy lead-sulfate" turns into a hard/black crystal that no longer participates in the charging/discharging chemistry--And also "insulates" the plate surface).

    There are "de-sulfators" that people sell who claim can recover sulfated batteries--But there is great controversy about whether they work or not (this is the only discussion here that "routinely" results in locked threads).

    Which Trojans do you have? If they are AGM--Then setting for 6 months should not have sulfated them (AGM batteries have lower self discharge). Your next issue is you may simply not have enough charging current. For example:
    • 8 batteries x 420 AH * 7.3 volts charging * 1/0.77 panel+controller deratings * 0.02 rate of charge = 637 Watt array Float Service
    • 8 batteries x 420 AH * 7.3 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 1,593 Watt array minimum
    • 8 batteries x 420 AH * 7.3 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 3,185 Watt array nominal
    • 8 batteries x 420 AH * 7.3 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 4,141 Watt array "cost effective maximum"
    So--If you had setup the charging system to "float" your battery bank when you received it--It should have kept your batteries relatively "happy".

    If you start cycling the battery bank, you really need more solar panels to do it justice.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Welcome to the forum.
    The509 said:
    Each day they seem fully charged but
    Why do you say they seem fully charged?  
    The509 said:
    I bought 8 Trojan L16 last year before the fires.
    <snip>
    The only load I have on them is a couple cigerette lighter outlets charging iPhones.
    That's like driving an 80,000 lb dump truck into town to pick up a quart of milk.  Your battery bank is enormous for the size of your load.   As Bill mentioned, under normal circumstances, your array is too small to charge up that much battery. 
    The509 said:
    Xantrex MPPT and 3 X 250 watt panels.
    Are those three panels in series or in parallel?  If they are in parallel, that is part of the problem.  What are the charge settings on the controller? (in particular, what is the absorb voltage and absorb duration?)  What other equipment do you have?  (inverter, battery charger, battery monitor, etc)

    --vtMaps


    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • PhotowhitPhotowhit Solar Expert Posts: 4,280 ✭✭✭✭

    VtMaps makes a good point, many 250watt panels have too low VMP to properly charge 24 volt battery banks.

    If they are flooded batteries, equalizing may help recover some of the lost capacity.

    What settings are you using with your charge controller?

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • The509The509 Registered Users Posts: 22 ✭✭
    @BB The sitting idle was beyond my control due to the wildfires here last year..I was thinking about ordering 2 more panels this week and would like to be up to 8 total st sum point. The sad thing is we really don't use that much power. Id be surprised if we used 2 KWHs a day during the summer when the kids are home all day..  L16RE-B

    @VTmaps, im going off output and input on my Xantrex.  Im still learning and figured that if my batteries are on float with no real load that they are for the most part charged..My panels are wired in Parallel..
      http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/kyocera-solar-panels/kyocera-ku265-6mca-265-watt-multicrystal-solar-panel.html

    I really appreciate the help. Im trying to take this all in

  • BB.BB. Super Moderators Posts: 26,872 admin
    Sorry about the fires--It was bad last year.

    Your best bet would be to design the system to the amount of power you want to use (summer/winter) and go from there.

    Do you have utility power, or is this a pure off grid system? 1-2kWH per day is a nice job of conserving power. Does not sound like you are running a refrigerator or large well pump, etc.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • The509The509 Registered Users Posts: 22 ✭✭
    Im off grid, fridge is the huge Crystal cold propane, stove and water heater are propane as well...I could run power for about 5gs. But my wife and I like the whole no electric bill thing..Coming from Texas were we paid 300-400 a month to buying 500 gallons of propane each year is fantastic.

    Well is in, and yes, its electric, but when i built, i put in 2, 500 gallon water tanks.. So i just turn on the Briggs and fill them up, once a month normally.

    VTmaps said i should of wired my panels in series versus parallel. Do you know why?  Should I go up and change them now? 
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    The509 said:
    My panels are wired in Parallel..
    Those panels are not able to charge a 24 volt battery when they are in parallel.  An MPPT controller needs a certain amount of 'headroom' in which to operate. (in other words, input voltage must be higher than output voltage).  

    Your panel's Vmp is 31 volts, but in the hot sun it will be several volts lower.  Meanwhile your battery needs 29-31 volts.  An MPPT controller should have its input voltage at least 12 volts higher than the battery charging voltage. 

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • The509The509 Registered Users Posts: 22 ✭✭
    So i just ran them in series.  How many more panels am i looking at?  My goal thru all this is really for the kids to come home and run the TV and Xbox for a couple hours after the sun is down..Nothing more..Is there a certain type of charger i should get?
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    edited March 2016 #10
    He probably would tell you to run 2 panels in series into the controller. You need an even amount of 2 panels per string. The strings are in parallel.

    At a minimum you need one more panel.  2 x 2. Your charger is fine. Measure SG and do an EQ . List your set-points here!

    You really need to do somethings soon as the morning voltage of the battery should not be below 24V on most days. My systems are at 24.5V  and usually 25V in the morning. 
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    The509 said:
    So i just ran them in series.
    Hold on there... those panels have a Voc of 38.3 volts.  If you put 3 in series the string Voc will be 114.9 volts.  That's probably OK, depending on where you live.  If you are in a very cold climate, the Voc could rise high enough to fry your controller.

    Also, although MPPT controllers need headroom, too much makes them inefficient (runs hot, shorter lifespan, less capacity to handle power).   In other words, 114.9 volts input may work, but it is not optimal.

    Panels such as yours (and mine) with a Vmp of 30-31 should be configured with a string length of 2 (Vmp = 60-62) when used in a 24 volt system.  In other words, you need an even number of panels.  You should also have a combiner box with circuit breakers.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • The509The509 Registered Users Posts: 22 ✭✭
    right now, nights are close to 30.Should I go run 2 in series, and one pos to pos?  until i get my new panels in?
  • westbranchwestbranch Solar Expert Posts: 4,873 ✭✭✭✭
    Fill in the gaps here please...  how far away is the cabin?  how long a drive, etc..  When will the other panels arrive?

    YOU NEED TO , ASAP, GET A BETTER CONFIGURATION OF THOSE PANELS DONE, LIKE TOMORROW, IF ABLE, TIME IS OF THE ESSENCE  FOR YOU TO SAVE YOUR BATTERY INVESTMENT!

    3 panels will be the best for the interim, then change it to 2s x 2p or 2s x 3p or ....  S = series p = parallel...

    hope this helps
     
    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, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • The509The509 Registered Users Posts: 22 ✭✭
    im in the middle of nowhere..The closest big city is Omak Wa..population 5000.. I ordered 3 more panels but it will be a week before they get here..I unhooked the 3rd panel and im running the other 2 in series. Is there a way to tie the 3rd panel in without risking anything? 
  • westbranchwestbranch Solar Expert Posts: 4,873 ✭✭✭✭
    as VTmaps said "Hold on there... those panels have a Voc of 38.3 volts.  If you put 3 in series the string Voc will be 114.9 volts.  That's probably OK, depending on where you live.  If you are in a very cold climate, the Voc could rise high enough to fry your controller."

    Yes, you could run 3  in series, but you have to confirm that is within the max limits of your controller which you have not fully identified the model you are using to us.
    hth
     
    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, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    edited March 2016 #16
    He said an mppt-60-150 and so he is fine for now. Just not a good way to run this combination. With winter an all still, I would run these all in parallel to get more power and then rewire before it gets warm or with new panels.
    Probably get the generator going and give a nice long 4 hour absorb and then an EQ and measure SG
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • The509The509 Registered Users Posts: 22 ✭✭
    So, put them back the way they were until i have 6 panels, then run 3 sets of 2 in series, and charge for 4 hours today..So, don't flame me for this, but i switched over to 24 volts like a month ago. i don't have a 24 volt charger i have a Pro Series 30/60 12/6 volt, but i can run down to sears and grab one today..When you say charger, are we talking something like this? The associated brand?   http://www.sears.com/search=24 volt battery charger    The charger was gonna a be a question for a later day 

  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Are you planning to buy an inverter?  If so, buy an inverter/charger.  If you buy just a 24 volt battery charger, make sure it can put out at least 60 amps.   I don't think you will find anything at sears that can do that.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • The509The509 Registered Users Posts: 22 ✭✭
    edited March 2016 #19
    i have a 24volt AIMS Pure Sine which i really like..

    specs on the in stock charger

    Associated Equipment 6006 6/12/24V 70/65/30 Amp Charge 280 Amp Cranking Assist Charger with Wheels




    Not good enough>?
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    Anything will do for now!  Just get them charging and measure/list the SG
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • The509The509 Registered Users Posts: 22 ✭✭
    batteries 1-8
    1250 1225 1225
    1225 1230 1225
    1250 1225 1230
    1215 1210 1175
    1150 1125 1100
    1250 1225 1200
    1200 1150 1150
    1225 1225 1220
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    And so this data is after what kind of charging?
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • The509The509 Registered Users Posts: 22 ✭✭
    Normal day, no real load, CC said i put 1.98 KWH into the bank..I unhooked the CC from the batteries for about 30 mins before i did the test which was 15 mins before i posted.. The CC said Float pretty much all day, .Sorry i cant be more specific. What info are you wanting i might be leaving stuff out
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    edited March 2016 #24
    Well, you can see from your chart that you have both of the basic problems flooded batteries can have when not charged properly.
    You have large differences between the readings and at least one battery that is far different than the rest.

    The info needed is what is the bulk absorb set to? (it should be around 29.5V)  What is the absorb time. (it should be 3+ hours)  And what is the EQ voltage? You should verify the numbers with your trojan manual and verify there is a temp sensor on the mppt.

    If I were you I would do a 1 hour EQ @ 31V after you go to float. Then check the lower reading cells and see if they come up.
    Then do more 1 hr EQ's. Good Luck!

    Look at your battery wiring and maybe take a picture of it.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • The509The509 Registered Users Posts: 22 ✭✭
    i used this chart off the net i can take a pic if you want but thats how its hooked up..bat 1 is top left 2 is below and so forth if your looking to compare the numbers i posted earlier..
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    How about all the set-points and charging data? A pix is nice but you really need to address the earlier part about loading.
    A couple of cell phones is not going to pull the bank down to 23V, even with the low SG readings. So that is one ? thing.
    After you get the batteries closer in SG, I would get a 1500 watt electric heater and start putting loads on the bank. More later after you
    list your set-points please.

    Fires always suck! we just have to live with them and be safe.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • The509The509 Registered Users Posts: 22 ✭✭
    ill get the points..after hooking up the panels in series, i haven't dipped below 24volts when i wake up..And that's just the 2 panels as i unhooked the 3rd after you guys told me it wasn't a good idea..i have 3 more coming in
  • The509The509 Registered Users Posts: 22 ✭✭
    Eq is 32
    Float is 27
    Bulk and Absorb are both 28.8
    and absorb time is 180 mins

  • BB.BB. Super Moderators Posts: 26,872 admin
    Do you actually get 3 hours of "absorb" in a day? (i.e., battery bus voltage >28.8 volts for 3 hours per most days)?

    And according to this--The 77F daily charging voltage should be around 29.6 volts (if I got your correct battery type):

    http://www.trojanbattery.com/pdf/datasheets/L16HAC_Trojan_Data_Sheets.pdf

    -Bill

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    edited March 2016 #30
    32 is a little high but should not hurt with the SG's you have. Your Absorb is too low. It should be at the high end of Trojans 2.35 to 2.45v per cell. I would set it to 29.4V . If there is a temp sensor it will be higher this time of year.

    Did you do an EQ ?  

    Hi Bill !  he said it is in float all the time. And whatever the trojan type battery Bill's 29.6v absorb will not hurt.

    The load test is needed to find out more. He probably does not get the full absorb as the xw charger will go to float at 2% of the capacity setting. This is a good point Bill. 

    509, I would set your battery capacity for now down at 200 AH. This will keep the charger at absorb longer.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • The509The509 Registered Users Posts: 22 ✭✭
    Doing EQ now at 31..Will change the absorb when its done.. What should i do with the 3rd panel while i wait for the other 3? 
«1
Sign In or Register to comment.