Charging battery’s I figured I could charg

wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
Good morning , 
 I thought I would start a new  discussion 
  I have 3 295 watt solar panels in series now ,  would that be enough power to float my16  gc215 battery for 48 volts at 430ahs ? 
 The battery’s have been sitting for 4 weeks now and I have been charging them with 2 car chargers at 12 volt on the weekends to keep them up . 
  I rigged up the 3 panels to  a water tank for now I get sun from 800 when the controler wakes up till about 600 when it tappers off . 
 I don’t want to risk 3 more panel , I have 3 large bears that like to walk my pavers across the side of the house and it would be easy to just have some one walk of with them .
 It looks like it will be 5 weeks before I have the time to put them on the roof . 
 I figured I can bulk charge from my genarator for now when I get it hooked up . 
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Comments

  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    Could any one tell me how much power my flex power one uses wile inverting ? 
     It seemed like it drained the battery’s over night kinda fast with a small 20 watt fan and a few led lights 
     my battery dropped from 100% to 93% in 5 hours then from 93% to 85% over night ?
     Seams like a lot ? This was on 8 gc215 ah 48 volt battery’s . 

    Out
  • mcgivormcgivor Posts: 2,044Solar Expert ✭✭✭✭
    State of charge is difficult to accurately monitor, if done by voltage, very inaccurate, if done by shunt resistor, amps in versus amps out, somewhat accurate. There are some points I would like to make which may seem judgmental, but the intentions are not, don't use a system which is not complete, charging batteries to different levels with car chargers will lead to imbalance, which will rear it's head later on, this can be corrected but best not to develop the problem in the first place. Never underestimate loads, what seems like a minor load can, with the inverter self consumption actually be a major load over time.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • BB.BB. Posts: 27,682Super Moderators admin
    Need more details (model number of inverter?)... For a generic view, you can see how low loads on a large AC inverter, the efficiency plumits (basically falls at less than ~2kVW loads for the larger Outback inverters):

    http://www.outbackpower.com/downloads/documents/integrated_systems/flexpower_radian/flexpowerradian_specsheet.pdf

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    Mcgivor I’m not really trying to use the system I thought this was going to move along faster then it is .
     I bought the battery’s sooo I’m in the game now .
     I have to deal with it . 
     I think I should have the utility room finished up in the next week or so .
     I just need to float the battery some how till I get all the panels on the roof . 
     So is 885 watts going to float my 430ah battery.   

       I have a flex power one 3600 watts 48 volt inverter with flex max80cc 
     I have 24 295 watt panels .
     I will put panels on the roof and some on the ground  I’m thinking 18 panels on the roof 
     I will addaseconed CC 
    Out
  • jonrjonr Posts: 1,026Solar Expert ✭✭✭✭
    > So is 885 watts going to float my 430ah battery.

    If you don't put any load on it, yes.   You can verify by measuring voltage after the batteries sit for say 6 hours with no activity (load or charging).
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    That is good news 
     so will 3540 watts  12 295 watt panels charge my 430 ah battery ? 
      If not how many should I use . 
    Out
  • BB.BB. Posts: 27,682Super Moderators admin
    Assuming you have a 48 volt @ 430 AH battery bank (not sure which batteries you have with a quick search):
    • 3 * 295 Watt panels = 885 Watts
    Recommend 2% or possibly 1% rate of charge for "floating" already charged battery bank:
    • 58 volts charging * 430 AH * 1/0.77 panel+controller deraring * 0.01 rate of charge = 321 Watt array minimum Float charging
    • 58 volts charging * 430 AH * 1/0.77 panel+controller deraring * 0.05 rate of charge = 1,605 Watt array minimum (weekend/seasonal usage)
    • 58 volts charging * 430 AH * 1/0.77 panel+controller deraring * 0.10 rate of charge = 3,210 Watt array nominal (full time off grid)
    • 58 volts charging * 430 AH * 1/0.77 panel+controller deraring * 0.13 rate of charge = 4,173 Watt array typical "cost effective" maximum
    If you are somewhere around NYC, then you may not have very good sun during winter:
    http://www.solarelectricityhandbook.com/solar-irradiance.html
     

    Brooklyn
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 49° angle from vertical:
    (For best year-round performance)

    JanFebMarAprMayJun
    3.31
     
    4.03
     
    4.74
     
    4.94
     
    5.10
     
    5.28
     
    JulAugSepOctNovDec
    5.21
     
    5.16
     
    4.93
     
    4.47
     
    3.39
     
    3.08
     
    For July, the average day's harvest would be around:
    • 885 Watts * 0.52 off grid system eff * 5.21 hours of sun per day = 2,398 Watt*Hours per day "July"
    Of course, your battery is really only getting float charging, and most of the harvest energy will probably be used up keeping the bank charged... But an example of the math for predicted harvest (I know there are few bears in Brooklyn). Plug in your location/numbers...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Posts: 2,594Registered Users ✭✭✭✭
    My 3500w Outbacks are also pigs with small loads. If I leave on overnight to run the AC fridge, my [email protected] bank gets to ~85%. I suspect it wouldn't be much better running a few lights and a fan. Running pretty much anything seems to take at least a couple of amps.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
     Bill All the bears in Brooklyn are in the zoo or on the ball field .
     In December I have 2.75  so not to good really ,
    I’m hi up and it seams very bright  especially with snow on the ground . 
     My controler is rated for 4000 watts 12 x295 =3540 watts could I add 15 x295 =4425watts ? 
     How much solar is to much .
     Could I add more panels,  say a extra ? 12 x 295 watt  on a second flex max 80 for low sun days I don’t know how much it would help . 
      Estragon , 85% seam crazy high , 2500 watts ? I was told the system would draw 800 watts a day , I guess it is what it Is . How much power is the fridge drawing ? 
      I don’t think my lights , fan , tv and I phone charger draws more then 70/80 watts. 
     I was running for 14 hours with mixed loads but 10 hrs I had just a 20 watt fan and 2 led lights 6 watts each .
     I’ll have to just try my inverter with a light burning for 12 hours and see what I get .? 
    Out
  • BB.BB. Posts: 27,682Super Moderators admin
    Remember:

    Watts = Rate (like miles per hour)
    Watt*Hours = Amount (like miles driven)

    So, from a system point of view, you need to know your peak continuous loads (like 2,000 Watts of peak loads--Well pump, etc.).

    And then there is the hours per day you run your load... For example, a full size energy star rated refrigerator/freezer may run 1,000 to 2,000 Watt*Hours per day... An example of what a "mixed cycle" might look like:
    • 120 Watts * 0.50 duty cycle * 24 hours per day = 1,440 Watt*Hours per day (frost free refrigerator/freezer)
    Note that a frost free fridge may take upwards of 600 Watts starting the compressor (5x running watts is not unusual for "standard" induction motor loads). And the refrigerator may take ~500-600 Watts for a period of time running the defrost cycle (typically deicing the internal evaporator). Overall, the frost free are still pretty energy efficient with the "costs" of defrosting. My fridges tend to run a defrost cycle every 12 hours. And one old time poster here deactivated auto defrost and found that after ~24 hours, the evaporator iced up enough that the fridge started using more electricity due to blocked/inefficient cooling.

    With a larger inverter, it may take 40-50 Watt just turned on (50 watts * 24 hours per day = 1,200 WH per day). Then add the "20 watt load" and ~85% efficiency (20 watts * 1/0.85 = 24 watt on DC bus, plus the 50 Watt tare load--purely an example).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westbranchwestbranch Posts: 5,083Solar Expert ✭✭✭✭
    edited July 18 #12
    Remember there is also a 50 +/- full cycles to most batteries break in period before they will stabilize, but worry about that later, get those 3 PVs working and add more asap... What are the  (manufacturers charging ?) specs that you are using?

    ps a 20 Watt fan over 14 hours uses at least 280 Watt [*Hours or 280 WH] of power at ~50 Volts = 5.6Ah from your battery or about 9.6Ah for 24 hours.

    Add all the items together  your 80 W yields 80*14= 1320Whr  and that is equivalent to a fridge's draw for the whole day in cooler weather

    [edit: BB.]
     
    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
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    I’m not to worried about the % of battery used , after thinking about it I was running on half my battery bank for 14 hrs 
     my CC went to sleep around 600 and the sun hit the panels at 800 but did not start charging till 930 when It turned on , 
     so 151/2 hours really . 
     I did not want to have to turn my inverter off at night ,  it’s cool in the house it stays about 67o even when it’s in the 90s for days .
     I am hopping to stay with my gc battery’s but I’m making the battery box to fit 16 l16 for more power when we live there full time just in case . 
      So how much solar power is to much ? I have 66 recesslights 400watts if I turn them all on , I can dim them and save 150 w  I think I can live on 3000watts a day plus a frig and inverter loss 5500 watts I think my bank should provide 590 watts for 2 days . 
     I bought the out back system from our  host on there  recommendation . 
     I was hopping to charge the battery’s in the winter on cloudy days run the regular house loads and be able to start my frig and cycle the washer and dryer all at once. 

    Out
  • mcgivormcgivor Posts: 2,044Solar Expert ✭✭✭✭
    edited July 18 #14
    Read post 11 again wattage is not a measure of consumption without a time base included.
    edit missed per day, so 3Kwh or 5.5 Kwh per day
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    Yes thanks mcgiver 5.5 KWHs per day .
    Out
  • Raj174Raj174 Posts: 634Solar Expert ✭✭✭✭
    edited July 18 #16
    @wellbuilt
    You ask, how much is too much. It's really determined by the batteries. Your 430 amp hour bank can take a max of about a 60 amps, that's a charge rate of about 13%. 12 of the 285 watt panels would produce this much power under perfect conditions. However, in the real world, the output would be 20% to 25% less, so I would suggest installing 15 panels and tweak the system later if you need to. 

    Rick  
    3600W PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 207AH LiFePO4 no BMS, 4500W genset.
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    West branch , 
    east penn was not much help .
     The girl that answers there tec support line was not very  technical  , I would ask a question and she would have to ask some one  behind the scenes . 
     She was very sweet but not a lot of help . 
     I copied some set points from some one on line with the same battery’s figureing he must know more then I do at this point . 
     Rick  Estagon and Mcgiver helped with the set points in a different thread .
     The battery’s are deracell gc 215 from sams club .  
     
    Rick ,
     so you think my fm80 cc would be ok with 295x 15 = 4425 watt of solar ? 
     The controlers max wattage is 4000 watts ? 
      The guys at Arazona wind and sun told me that they   Regularly use 4700 watts of solar on that controler but he was the only person that has said that .
     I don’t want to add a second controler for 3 panels would it be ok to run 2 banks of 9 panels on 2 fm80s and limit the amps on the controler? 
     This would give me more power on cloudy days and in the Future if I upgrade my batteries are 16 l16  I would already have enough power to charge them .
     I bought 24 panels for a good price and I figured I would use 18 for charging battery’s 5 for sucking water from my 800’ deep well and one extra  ( just in case some one butter fingers a panel )  the roof is walkable for trades men 9 on 12 .
    Out
  • littleharbor2littleharbor2 Posts: 979Solar Expert ✭✭✭✭
    9 in 12 is walkable? I realize these days everybody uses fall arrest gear but 9 in 12 would be more like rappelling to me.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • Raj174Raj174 Posts: 634Solar Expert ✭✭✭✭
    Yes, it's definitely ok to have 4425 watts on the FM80 and the charge current can be limited if necessary. 

    Rick
    3600W PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 207AH LiFePO4 no BMS, 4500W genset.
  • EstragonEstragon Posts: 2,594Registered Users ✭✭✭✭
    With lots of panels relative to bank size, what's likely to happen most days is the bank will get fuller with lower morning sun, likely hitting absorb well before full sun around solar noon. In absorb, the panels won't be producing at capacity anyway unless you're running lots of loads.

    I have 18 x 250w panels = 4500w STC for a 350ah bank on a pair of classics and it works fine.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mcgivormcgivor Posts: 2,044Solar Expert ✭✭✭✭
    Raj174 said:
    @wellbuilt
    You ask, how much is too much. It's really determined by the batteries. A 430 amp hour bank can take a max of about a 60 amps, that's a charge rate of about 13%. 12 of the 285 watt panels would produce this much power under perfect conditions. However, in the real world, the output would be 20% to 25% less so I would suggest installing 15 panels and tweak the system later if you need to. 

    Rick  
    Batteries, weather, season, depth of discharge will all play a part in the equation, having more than needed is useful when the days are short and gloomy, Rick is probably about right given geographic location, during periods of excess a string could always be turned off to reduce current and some controller can limit current  to a desirable level. With similar loads in the tropics I'm able to get away with 1500 w rated PV, for what that's worth, probably your peak summer output, in terms of production, only year round. Design for the lowest winter months and adjust accordingly. 


      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    😂. Little  Harbor  You guys must be offIce guys . 
     I’m a builder , I’ve built from the ground up for my hole life and yes we get to the roof . 
     I am getting to old for  shingling but some one has to frame the roof . 
      I’m having foot problems now so I’ve given up walking on the roof , buuuuut let me help you guys out with this pitch thing . 

     All you need is some old  couch foam 4” thick . 
    You can drop the  couch cushion on the shingles and stand on it ,  it’s almost like a day off . 
     Back in the day a 12/12 was  workable pushing  60 years old I just can’t risk a fall , but on my house I have no choice . 
      My sons run a 9 pitch like it a side walk. 
      I’ve never used a  safety harness  😜 
    Out
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    Rick ,
     that’s what I’ll do , I’ll add 15 295 watt  panels  @ 4425 watts on my roof and set up a second array on the ground at some point . 
     That’s good news I feel better with a little more power . 
    Out
  • littleharbor2littleharbor2 Posts: 979Solar Expert ✭✭✭✭
    wellbuilt said:
    😂. Little  Harbor  You guys must be offIce guys . 
     I’m a builder , I’ve built from the ground up for my hole life and yes we get to the roof . 
     I am getting to old for  shingling but some one has to frame the roof . 
      I’m having foot problems now so I’ve given up walking on the roof , buuuuut let me help you guys out with this pitch thing . 

     All you need is some old  couch foam 4” thick . 
    You can drop the  couch cushion on the shingles and stand on it ,  it’s almost like a day off . 
     Back in the day a 12/12 was  workable pushing  60 years old I just can’t risk a fall , but on my house I have no choice . 
      My sons run a 9 pitch like it a side walk. 
      I’ve never used a  safety harness  😜 
    I was in construction my whole life, and, yes, we built from the ground up as well. . Have done literally hundreds of roof jobs. I wouldn't get on a 9 in 12 roof without roof jacks. Where the hell are you going to put your shingles? On a sky hook? How do you keep anything on a roof that steep? You'd have shingles raining off the roof all day long. not to mention dragging silly looking foam rubber cushions around with you. 
     I'm not surprised you are having foot problems walking on pitches that steep. Walking on clean plywood is doable with some cleats nailed down but with sawdust blowing all over the place it's quite dangerous. BTW I was out of the business before all this ridiculous fall arrest gear was required in this area.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mcgivormcgivor Posts: 2,044Solar Expert ✭✭✭✭
    Where the hell are you going to put your shingles? On a sky hook? How do you keep anything on a roof that steep? You'd have shingles raining off the roof all day long.


      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • littleharbor2littleharbor2 Posts: 979Solar Expert ✭✭✭✭
    mcgivor said:
    Where the hell are you going to put your shingles? On a sky hook? How do you keep anything on a roof that steep? You'd have shingles raining off the roof all day long.


    Piece of cake with roof jacks. :#

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    LH we use a feeder , one guy stays on the ridge and slides the roofing down a few shingles at a time to to guys roofing below .
     Or they keep the roofing on the tops of there feet. 
      The guys run up 6 shingleshigh  3 wide. 
     The silly foam holds the roofing also , laying the shingles on top Over lapping the edge. 
      My roofers just stand on a 9 pitch even shooting on the first course . 
      A 12 pitch slowed them down a little . 
      At 14/12 they use the brackets and ladders .
     when I was in my 30s I would walk a 9 or 10 pitch no problem for ply wood or framing 
     I did not personally roof much after that I allways had my roofers , funny thing is the same guys are still roofing for me today.
    Out
  • PhotowhitPhotowhit Posts: 4,660Solar Expert ✭✭✭✭
    edited July 19 #28


    My cabin, not much over 12/12, I know roofers are crazy... but no...

    Every time roofing comes up I love to tell the story about the housing boom in Central Florida in the 1980's. Companies would drive up from central Florida and hire entire crews off of roofs! 50% more money, room and board and a ticket home after 10 days if they wanted to go home. It's no fun working on a roof in the summer time (taring flat roofs even worse) One of those jobs I'd do for my self, but wouldn't do for others. Mason's helper might be worse, but it would be a close thing.

    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.
  • littleharbor2littleharbor2 Posts: 979Solar Expert ✭✭✭✭
    edited July 19 #29
    wellbuilt said:
    LH we use a feeder , one guy stays on the ridge and slides the roofing down a few shingles at a time to to guys roofing below .
     Or they keep the roofing on the tops of there feet. 
      The guys run up 6 shingleshigh  3 wide. 
     The silly foam holds the roofing also , laying the shingles on top Over lapping the edge. 
      My roofers just stand on a 9 pitch even shooting on the first course . 
      A 12 pitch slowed them down a little . 
      At 14/12 they use the brackets and ladders .
     when I was in my 30s I would walk a 9 or 10 pitch no problem for ply wood or framing 
     I did not personally roof much after that I allways had my roofers , funny thing is the same guys are still roofing for me today.
    Clearly these things are done differently in different parts of the country. I can't see a good reason to not use roof jacks on any pitch that material would slide off on it's own. They are a piece of cake to use and give you a sidewalk up there to walk on as well as a safe, secure place to stack your material, 
     I generally worked solo. When I did have a helper feeding me material I put down as much as 20 squares in a day.
     Looking at Photowhit's  picture, above, I couldn't imagine working on that roof without jacks


    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    PW very sweet cabin .
     That is exactly what I wanted 
    but in my area it doesn’t make sense , water elec , septic ,road work land permits etc are very  expensive .
     The zoning in NY calls for 800 sf living space ,my town wants 1300 sf  then Wilfy started drawing plans .
     I started out with a first floor plan of 1300, to meat zoneing code . 
     I wanted to leave the second floor unfinished but I had most of the material on hand and ended up adding the stair well 
    and second floor  partitions  , roughed in a bath .
     I ended up just finishing the second floor , the nice tax lady keeps talking sweet to me 😍 here’s a pic of the front roof before the porch was added , I had the roofers set up sweet , the guys took the  brackets off before they started 😳
     the gray roofing paper is sticky compared to regular tar paper  .
     The garage and main house has ice shield over the whole thing , the guys roofed it in 10 hours 33 sq  then came back and roofed the porch .
    the pic is the day before we roofed it up and the day after . 

      
    Out
  • wellbuiltwellbuilt Posts: 283Solar Expert ✭✭✭
    Little harber , I allways wanted adjustable roof brackets like that mine are mostly fixed 8 pitch 2x8 brackets.
      Why Is the aluminum flashing in the valley,  it looks like The roofing is  weaved very nicely ?
     In my area we would roof up the valley with no flashing .
      Starting in about 1995 every one used ice and water shield up the valley but it would be stuck to the plywood and roofing felt would be over the top .
    Out
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