Xw xantrex inverter constantly charging

Kefalonianman
Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
Everything been working well I hit a charge every two days when house empty but since I been here the system seems to want to constantly charge for 4 hours at night I have tried moving grid support voltage to see if any different but nothing

Batteries have been equalised and I tested with hydrometer and all around 1.25 and topped up any which needed only or or two cells

Any idea why the sudden recharge for so long every night I have using 15 kw a night just charging batteries

Very confused
Paul

Comments

  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    Hi Paul
    A little more info might help with diagnosis. Age of batteries? Are they all in good condition? What's your total daily consumption? Total daily harvest of wind and sun?

    A neighbour had 2 bad cells in his bank, overcharging occured and ruined most of the rest of the bank (salvaged 4 out of 16 batteries).

    I suspect battery problem. Is your bank 2 x 8 units making the 24? You probably should check the sg in each cell, and the voltage of every battery individually.

    let us know what you find (maybe limit your grid charging amps, just float charge with grid)

    Ralph
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    I have 16 * 105 trojan
    I have checked with hydrometer and all look good check water all pâtés covered although added a small amount
    The batteries are two year old, I equalised this morning and checked water again afterwards all look good.

    While equalising at 31.6v I had a reading of about 1.280

    At the moment I using approx 600 w and I have my mptt on bulk charge which are powered by 12 185 watt panels and two 700w turbines but no wind just sun today

    Does this help
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging

    Four parallel strings of four 6 Volt batteries. That can be a problem right there. 900 Amp hours @ 24 Volts trying to be charged off an array of 2220 Watts. That can be a problem too, as it's only capable of about 70 Amps of current whereas the batteries may need 90. One 60 Amp charge controller will choke off that extra 10 Amps the panels can produce.

    Without the wind turbines' contribution you're charging at about 6%. Not too surprising the batteries are asking for power from the grid at night then. I think Ralph is on the right track here; you need to disconnect one string of batteries at a time after a day's charging, let it rest a couple of hours, measure the Voltage on each battery and the SG on every cell and look for discrepancies.

    If you only use 600 Watt hours per day, why have a battery bank capable of over 4000 Watt hours? The XW4024 only needs about half of what you've got to function properly with GT, and your panel array can not support that much battery. I would suspect here a case of chronic deficit charging resulting in damage to some if not all the cells.
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    I am running lean at money as pool broke normally an extra 500w from 11am till 6pm and I am also in the process of having another 4 panels installed but at 220 w er panel

    Would this make a difference

    I could disconnect one bank of 8 batteries but I do not want them to go to waste as expensive is there any way of storing them or shoud I switch to 48v woud that be better although turbines are 24v

    Paul
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Xw xantrex inverter constantly charging

    I would also suggest getting an inexpensive DC Current Clamp Meter (such as this one)... And measure the charging/discharging of each string. If you find one string pulling all of the current (or another accepting none), you at least have a place to start.

    But if all of the batteries are taking about the same amount of water every month or two--then I am not sure the DC clamp meter would show anything useful in this case.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging

    Right now your 60 Amp charge controller has two 185 Watt panels too many on it:
    60 Amps * 24 Volts = 1440 Watts less 77% efficiency derating = 1870 Watt array

    Adding more panels without adding a second controller will not help. Adding them with another controller would bring you up to around 88 Amps of peak charge current and that should be enough for a 900 Amp hour battery bank.

    Budget-wise the best thing to do is check all the batteries individually after charging and look for the four worst ones, then take them out of the mix. They won't get better and continuing to run in a deficit charge state will cause the remaining ones to deteriorate faster. Switching to 48 Volts would mean changing the inverter, and they are not cheap at all!

    One of the problems with wind turbines; you can't count on them. When the wind doesn't blow, that's 1400 Watts of charging power that isn't there.

    Whatever you do, check those batteries and look for ones that are in trouble. Otherwise any changes will not be of much help.
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    Many thanks for your help already

    I have two charge controllers one with 4 panels and the other with 8(in two blocks of four)
    My inverter is xw 4024 so will take 48v no problem but the turbines are 24v
    Had a windy day Today and the turbines only seem to produce in gusts of 2 - 15 amps and that's between the two disappointing

    I had planned on adding another charge controller and 4 * 220 w panels on the space on the sW roof would this be ok seems to be in sun all day apart from first couple of hours

    I did some checks on batteries last night and although I had the plates covered Trojan recommend an eighth of a inch from the bottom of the filler so I topped them all upto that mark after charging

    I have done hydrometer readings and they all seem to be the same but what kind of reading should I be looking for and is there anything else besides the clamp which I am going to order can I do to double check the batteries

    Should I disconnect one bank and run for 24 hrs to see what happens or would the disconnected bank die

    Also the Mptt only ever to put just enough in about battery voltage are these best set on bulk 2stage and should the recharge volts be the same as the inverter and can it be higher to put then in full charge mode earlier

    Sorry for all the questions

    Paul
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Xw xantrex inverter constantly charging

    Paul,

    Be very careful of filling the batteries to within 1/8" of the top (that may be too full)... There is a chance they may bubble over and dump electrolyte out the caps.

    If there is another 1/4 to 1/2" worth of "vent slot" cut up the battery filler tub--then you are probably OK.

    The electrolyte liquid level vary quite a bit--between bubbles trapped in/at bottom of plates and temperature increases when charging, you want to ensure you have more room for electrolyte levels to rise during charging than an 1/8".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    Just noticed inverter charging again so switched it off and took the following readings

    Charger on 29.2
    Charger off 27.7 dropped to 26.6 immediately with 880 w load
    Switched pool off dropped to 25.6 by this time with 549w load
    Tested voltage on batteries and varied between 6.44 and 6.39

    Checked output on solaris and it was 11 kw
    Usage today I would say 6 kw so far

    Also checked wind turbines voltage about 32v each but only showing upto 15 amps current between them

    Should I equalise and then do hydro again

    Paul
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging

    Paul;

    You have an XW4024: it will not take 48 Volts! Do not try connecting it up that way or the magic smoke will come out and you'll be looking for a new inverter.

    The ideal specific gravity for the Trojans is 1.275. Consistent readings is a good sign, but if the SG is low that is not good. In all likelihood you are not getting enough Absorb time on the batteries. With the charger Voltage at 29.2 you are getting to the Absorb stage, but not necessarily staying there long enough to complete the charge.

    Battery Voltages and specific gravity should be taken with the batteries "at rest": no current going in or out for at least two hours. Otherwise you will get inaccurate readings. An at rest Voltage of 6.39 is excellent, but if that is the Voltage just off charging it doesn't mean much.

    Only equalize the batteries if there is a difference of 0.010 or more between any two cells. Otherwise the excess Voltage of EQ can do more harm than good.
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    Ok then tomorrow I will charge the batteries first thing and then turn the inverter off and run on mains and leve the batteries for two hours and then take all readings is it ok for me to send them to you once complete to give me some feedback

    Paul
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging
    Ok then tomorrow I will charge the batteries first thing and then turn the inverter off and run on mains and leve the batteries for two hours and then take all readings is it ok for me to send them to you once complete to give me some feedback

    Paul

    Post 'em up; we like everyone to be able to read about the adventures is solar. :D
    Plus it gives you the opportunity to hear different points of view as to the possible problem(s).
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    Breakthrough this morning the inverter was charging for 5 hours again last night so I worked back and decided to Dissconnect the turbines as I updated the charge controller just before the trouble nothing but then I noticed I have 4 old solar panels only 120w each on the charge controller and the cables and nuts were too hot to touch so I decided to Dissconnect these as soon as did the inverter dropped from 50 amps charging to 10 then stopped charging been running all morning at 27.7 v and that's with the washing machine on taking 1000 w constant fingers crossed that was the issue but why I do not know
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging

    Slow down a bit, please.

    You had four old 120 Watt panels on which charge controller? One of the turbine controllers or one of the solar controllers with the 185 Watt panels?

    The 120's would be "12 Volt" whereas the 185's would be "24 Volt". If these lower Voltage panels were connected incorrectly they could remove power from the array rather than add to it.
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    No the panels are connected correctly for 24v and they worked fine on previous charge controller but maybe this one is slight different

    Anyway disconnected run all day no problem with pool on as well
    No charging midday and it's not 5pm and still have 28v in batteries

    Looking ok I will post later once the sun goes down the day figured of the panels
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    Just had this reply from my solar supplier ur thoughts would be of interest


    Hello Paul, OK well things have changed. By this I mean that using both roof tops on one MPPT is an extreme no no. Why I say this is that first of all you will only have decent production @ 11 -13 pm about, the rest of the day the MPPT will be trying to find himself ( there will be a voltage difference between each slope, causing the MPPT not to work ) and also causing the Panels to age very fast, hot spots will start to form on the panels from the reverse current flowing back into the modules. Yes we can add protection diodes on the outside of the modules but still it won’t work ………………..
    *
    What I suggest is stay as you are 8 South working 100%, 4 SE working as hard as they can and then we add 4 SW but not Sovello. I will supply you with Eging Modules EGM 185Wp using a regular PWM Controller.
    They are 24Vdc so that means all four will be in parallel pumping out 22Amps total.
    *
    Let me know what you think !!!!!
    *
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging

    If I get the gist of it correctly, he's absolutely right: MPPT controllers do not like being connected to two arrays that aren't facing the same way. The result is that it will pick a power point that is wrong for both arrays, so you will never see the full benefit of either one.

    I disagree with the notion that such a connection will age the panels or cause "hot spots". If they are the same panels in the same configuration they would take application of up to Isc without incident, and that is very unlikely to happen. On the other hand I don't know how those particular panels are constructed, so you never know.

    But the lack of being able to get full output from either is the big red flag.

    Using a PWM controller for the new panels might not be the best idea either. I realize you don't get cold temps there like we do here, but check the wiring situation carefully; one of the main advantages of MPPT is its ability to use higher Voltage arrays and keep the current down. There is also a slight "Voltage overhead" advantage to be had even in warm climates. This is going to be another 740 Watts of panel, and that is well over the threshold for considering MPPT. The distance between the array and the controller location is a big factor, as is the difference in price between the PWM and MPPT controllers. Look at both options before you decide.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Xw xantrex inverter constantly charging

    Also look at what the Vmp of the "24 volt" panels really is... The "new" panels out there are not usually made to match the Vmp requirements for 12/24/48 volt battery banks.

    To be a "useful" 24 volt panel, you should be looking at Vmp in the 35 to 38 volt range or so...

    Many panels that are said to be "24 volt panels" actually have Vmp below 30 VDC and will not properly charge a 24 volt battery bank with a PWM controller.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Xw xantrex inverter constantly charging

    Specs on Eging Modules EGM 185W:
    Vmp 35.16, Imp 5.27, Voc 44.38, Isc 5.7

    So you're good there. But Bill is 100% right about panels these days often not being directly suitable for battery-based systems.

    BTW, they've over-stated the current in a parallel configuration: four @ 5.27 Amps each is 21.08 Amps, not 22. With an MPPT controller you might expect a couple more Amps peak (740 Watts @ 77% / 24 Volts = 23.7 Amps).
  • Kefalonianman
    Kefalonianman Solar Expert Posts: 60 ✭✭✭✭
    Re: Xw xantrex inverter constantly charging

    I think I would prefer to stick with the Mptt xantrex on the four panels on sW for now

    Another question just to confirm settings correct

    My solars worked all day yesterday keeping batteries at 27.7 and then last night grid support came in at 25 until this morning and it picked up again is there a setup to get the charge controllers to keep the batteries higher say 29.2 absorption all day as I used around 560 to 900 watts all day so I would say there is power there for the taking just don't know the settings to make it come through

    Many thanks paul

    Yesterday
    4.89kwh on bank of 8
    4.35 kwh on bank of 4

    Previous day when wife doing washing

    9 kwh on bank of 8
    4.9 kwh on bank of 4

    Interested in your thoughts