What's wrong, help needed....

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  • PhilS
    PhilS Solar Expert Posts: 370 ✭✭✭
    #32
    Re: What's wrong, help needed....
    CBHunter wrote: »
    I'm confused, 4175 watts on a MX-60??? In my owners manual they say that my Flexmax 80 can not handle more than 1250 watts with a 12 volts configuration.....

    I THINK Marc might have meant four 175W panels. At least it looks like there's a space between the first and second number in his post.

    Phil

    (on edit) Dang, but that Bill is fast.
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  • rickeolis
    rickeolis Solar Expert Posts: 110 ✭✭✭✭
    #33
    Re: What's wrong, help needed....

    Also, how far away is the wiring going to the pump from the inverter? Is the guage large enough to handle the distance and load at the same time?
    I've seen wire guage charts to help verify this.

    -Rick-
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #34
    Re: What's wrong, help needed....

    See what a typo will do for you? :p
    That is 4 x 175 watt panels! :p

    My pressure tank is 60 gallons - about 6 times the size ordinarily used!
    You can connect multiple small ones together; just keep them same size and close to each other so the pressure switch (which should always be at the tank, even though they habitually put them on pumps) isn't reading a 'wrong' pressure.
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #35
    Re: What's wrong, help needed....
    rickeolis wrote: »
    Also, how far away is the wiring going to the pump from the inverter? Is the guage large enough to handle the distance and load at the same time?
    I've seen wire guage charts to help verify this.

    -Rick-


    About a 100 FT, I was thinking of using 10 gauge....
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #36
    Re: What's wrong, help needed....

    Guys, since my battery bank is so large compare to my panel output, would it be a good idea to combine with a wind turbine?
    It's pretty windy at my cabin near the lake, beside most of the time when the sun is not shinnig the wind could take over? It even run during night time. What are your tought on this?
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #37
    Re: What's wrong, help needed....

    Generally speaking, small scale wind systems are not very efficient. You'll find a lot of posts here regarding this.

    More important to get a handle on what your power requirements really are and if you really need such a massive bank. Invest in a Kill-A-Watt meter first.
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  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    #38
    Re: What's wrong, help needed....

    No one the wind

    Solar is lower cost to add a panel or two and has no maintenance needs. Wind doesn't work in small scale, no exceptions
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #39
    Re: What's wrong, help needed....
    icarus wrote: »
    While that is generically correct,,, the error here is that the battery bank is SO large compared to the solar input,,, that the solar can just barely cover the stand by losses of the batteries. I would guess that your system puts out ~50 amps under ideal sun,, some where in the nieghbourhood of 2% of capacity,,, just enough to keep up at float, if that.

    The rule of thumb as I'm sure you know is ~5-13% would be normal.

    My hunch is that by leaving your batteries significantly discharge more than one, you have begun to kill your bank! Batteries left below ~80% for more than a couple of day will begin to sulphate in a hurry. As such they can't take much of a charge anymore, and can't hold one.

    As has been suggested,, I would give them a massive charge asap, keeping the specific gravity of each cell closely monitored until you get them all up to the proper SG.

    Tony



    My batteries are S-530 from Surette. To properly calculate my charging needs, what value should I used? They are rated 530 amps @ 100 hrs and 400 amps @ 20 hrs....?!
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #40
    Re: What's wrong, help needed....

    go by the 20hr rate which is most common. at 5% this would be 20a and would be the minimum. 13% is 52a. this does change things a little bit as i guess the 100hr rate they are showing may be more of a marketing ploy to make the battery seem better than it is.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #41
    Re: What's wrong, help needed....

    Around here, we us the rule-of-thumb of ~5%-13% of the 20 Hour Rate.

    Your best bet is to read the specifications from Surette (or even call/email and ask them).

    Many "private label" and random battries do not have detailed charging specifications/requirements and the rule of thumb helps as a quick guide for people with those (unknown type) batteries... However I believe Surette does.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #42
    Re: What's wrong, help needed....
    niel wrote: »
    go by the 20hr rate which is most common. at 5% this would be 20a and would be the minimum. 13% is 52a.


    Please explain your calculations....
    I have 8x S-530 in series parralelles wired for 12v. That is 1600amps-hrs. At 50% DOD = 800 amps. 5% of 800 is 40?
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #43
    Re: What's wrong, help needed....

    Your 530 ah of batteries would want a minimum of ~26 amps. Remember, the battery will loose 1-3% of it's charge per DAY on average,, more if hot,, less if cool. So at with that in mind,, you would need ~ 5-15 ah/day just to stay even.

    I would look to have a PV system that could deliver ~ 25 amps at a minimum,, ideally more. That would translate to PV array of about 600 watts or so might be a nice place to start. Also,, get a Xantrex TC 40 (or two) and fire up the genny as needed to keep them up. You asked about wind to augment the solar,,, but more solar would be a much more effective choice.

    They could take ~80 amps just fine. I would put as much charge into them as fast as I can now to get them up and keep them up. You have a huge investment in these batteries,,, and you risk burning that money up if you don't keep them charged. The bottom line is,, keep the charging capacity close to the proper size for the battery and the loads.

    T
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #44
    Re: What's wrong, help needed....

    Niel, Bill and I seem to be telecommuting this morning!

    T
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #45
    Re: What's wrong, help needed....
    icarus wrote: »
    Your 530 ah of batteries would want a minimum of ~26 amps. Remember, the battery will loose 1-3% of it's charge per DAY on average,, more if hot,, less if cool. So at with that in mind,, you would need ~ 5-15 ah/day just to stay even.

    I would look to have a PV system that could deliver ~ 25 amps at a minimum,, ideally more. That would translate to PV array of about 600 watts or so might be a nice place to start. Also,, get a Xantrex TC 40 (or two) and fire up the genny as needed to keep them up. You asked about wind to augment the solar,,, but more solar would be a much more effective choice.

    They could take ~80 amps just fine. I would put as much charge into them as fast as I can now to get them up and keep them up. You have a huge investment in these batteries,,, and you risk burning that money up if you don't keep them charged. The bottom line is,, keep the charging capacity close to the proper size for the battery and the loads.

    T



    OK, got it. I already have 4x 175 panels wich is 700 watts, and I have 2 more comming next week. So in total 1050 watts. I also bought an Iota 75 amps charger. You think it will do the job good?
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #46
    Re: What's wrong, help needed....

    i was going by the 400ah 20hr rate for 1 battery or any 1 series string. it is easy for you to extrapolate for the parallel operations you have. multiply the 20a by the number of parallel battery strings for the whole thing at 5%. follow?
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #47
    Re: What's wrong, help needed....
    niel wrote: »
    i was going by the 400ah 20hr rate for 1 battery or any 1 series string. it is easy for you to extrapolate for the parallel operations you have. multiply the 20a by the number of parallel battery strings for the whole thing at 5%. follow?

    Yes, thank you for the info!
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #48
    Re: What's wrong, help needed....

    Your panels might put out ~60 amps,,, in the good range,, the charger 75 amps. No reason that you couldn't run both for a while to get the batteries back up to snuff,,, the cc will control itself if the IOTA begins to bring them up to full. I would use the IOTA to help with the bulk charge,,, then let the PV take over for the absorb mode.

    Tony
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  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    #49
    Re: What's wrong, help needed....

    Pardon me if someone has suggested this already. My brother has the same problem as you in his system. When he start the water pump the battery voltage goes down to about 10V on the inverter side for a short period of time and the inverter shuts down. The voltage at the batteries drops to 10.7V so he has a 0.7V drop in the wires. His solution was to double the thickness on the cables and he is now considering adding a ultra capacitor across the DC input on the inverter.

    This is of course no cure for discharged batteries but in my brothers case it also happens when the batteries are fully charged.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #50
    Re: What's wrong, help needed....
    _OS_ wrote: »
    Pardon me if someone has suggested this already. My brother has the same problem as you in his system. When he start the water pump the battery voltage goes down to about 10V on the inverter side for a short period of time and the inverter shuts down. The voltage at the batteries drops to 10.7V so he has a 0.7V drop in the wires. His solution was to double the thickness on the cables and he is now considering adding a ultra capacitor across the DC input on the inverter.

    This is of course no cure for discharged batteries but in my brothers case it also happens when the batteries are fully charged.

    Sounds like another vote for a 24 or 48V system.
    The Ultra Cap won't help much. Look for ways to reduce the contact resistance losses. (clean fittings, proper torque)
    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 ,

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #51
    Re: What's wrong, help needed....

    Still, drawing the battery down to 10.7 volts--sounds more like a "starting" (like a car) situation.

    Higher voltage, more battery capacity (or more cells in parallel) are all going to help here.

    The other issue may be the batteries are showing the age and are not able to supply the peak current any more.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • CBHunter
    CBHunter Solar Expert Posts: 39 ✭
    #52
    Re: What's wrong, help needed....
    mike90045 wrote: »
    Sounds like another vote for a 24 or 48V system.
    The Ultra Cap won't help much. Look for ways to reduce the contact resistance losses. (clean fittings, proper torque)

    Interesting point, having 8 Surettes S-530 ( new ), would it be better to wire them up in a 24v configuration? 95% of my power requirements come from my well pump. ( ½ hp pump, 9 amps @ 110vac )
    As everybody mention on this forum, I have a cheap inverter that I planned to changed anyway, should I go 24v?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #53
    Re: What's wrong, help needed....

    An estimate of power at 12 volts (assuming 10.5 VDC minimum inverter input, 85% efficiency):

    9 amps * 110 VAC / (10.5 vdc * 0.85 invt efficiency) = 111 amps @ "12 volts"

    24 volt system would be 1/2 the current, and 48 volt system would be 1/4 the 12 volt system current.

    Inverters and Charge controllers are, frequently cheaper per watt in 48 volt systems.

    Charge controllers are rated at maximum output current:

    60 amp maximum * 14.6 volts * 1/0.95 efficiency = 922 watts of solar panels
    60 amp maximum * 50.2 volts * 1/0.95 efficiency = 3,170 watts of solar panels

    So, you can manage 4x the amount of solar panels with the same MPPT controller at 48v vs 12volts...

    Typically, I recommend to people that they keep below ~100 amps to keep wiring, fusing, and battery bank size (current ratings) at an easy to manage level.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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