Wellsee MPPT

moorsb
moorsb Solar Expert Posts: 38 ✭
in Solar Product Reviews & Opinions #1
Does anyone have one of these? I am looking at the 60amp unit.
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  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    #2
    Re: Wellsee MPPT

    I will be extremely surprised if its a MPPT unit ! The closest it will get to being such is the labelling on the case IMHO.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
    Re: Wellsee MPPT

    Well, see I tried reading the info on their web site but the English was so bad it was incomprehensible.

    Are they any good? We'll see.

    (Apologies; I can not resist a good joke. Or a bad one. :p )

    What would you expect for $133? A Morningstar 60 Amp MPPT is 4X the price.

    The specs, such as they are, do not impress.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: Wellsee MPPT

    coot,
    i don't blame you as i was thinking of the same thing with the name. if i made and was marketing a controller, it certainly would not be a wellsee as in we will see. possible new offshoot could be a maybnot.:p
    never heard of it before to comment, but if you get one then let us know what you think. i know, wellsee.:roll::p
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #5
    Re: Wellsee MPPT

    I bought 2 of them and they look cheaply made. I only have one up and running today. I am not using the load output. It cuts off the load at 10.5volt. By then your battery is dead. It would be nice if you could adjust that. There is a Red LED that flashes as it charges. It turns off at night and flashes at different rates during the day. It turns solid red when the battery is being used.

    How would I test the MPPT function?
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #6
    Re: Wellsee MPPT

    There are no meters on it, so without getting a Trimetric or similar it's going to be a bit difficult to determine if it's doing any good - or anything at all.

    Check the input and output Voltages with a DVM. If your nominal array Voltage is significantly higher than your system Voltage (24V array, 12V system) you should see that difference for starters. The trick is to check input Voltage @ input Amps vs output Voltage @ output Amps. If there is MPPT function the input would read higher Voltage at lower Amps and the output lower Voltage at higher Amps, both multiplying out to nearly (but not exactly) the same Watts.

    But remember that maximum charging will only occur if the batteries actually need it; if they're near charged they won't draw much current anyway.
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #7
    Re: Wellsee MPPT

    I put a voltage meter on the panel terminal and it shows 18.5 volts
    Battery term shows 13.5 volts

    I have a 500a shunt on the negative side and a 0 - 500 a meter. I pulses negative every time the MPPT chargers light come on. The Red LED flashes at different rates, very slow when the load is small. I will be putting a tri metic on it.

    It must be working as I hear the batteries churning.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
    Re: Wellsee MPPT
    moorsb wrote: »
    I have a 500a shunt on the negative side and a 0 - 500 a meter. I pulses negative every time the MPPT chargers light come on. The Red LED flashes at different rates, very slow when the load is small.

    This sounds suspiciously like the behaviour of a PWM controller, rather than an MPPT.
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #9
    Re: Wellsee MPPT

    I now have two of these in parallel. I have noticed that one seems to be charging and not the other. Do they need a diode on them to feed parallel?
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #10
    Re: Wellsee MPPT
    moorsb wrote: »
    I now have two of these in parallel.

    From the same PV array?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #11
    Re: Wellsee MPPT

    You can only parallel Charge Controllers on the output... For various reasons, you cannot parallel two chargers on the same solar array charging the same battery bank.

    Adding diodes on the array or at the battery bank will not help, and with the battery bank will mess-up the charging voltage readings by the charge controllers (diode drop) and may cause the controllers to not work at all (controllers usually need to sense battery voltage and use a small amount of power to even startup).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #12
    Re: Wellsee MPPT

    I am feeding a 2nd array to the battery bank. I am trying to get 120amps into the battery bank.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #13
    Re: Wellsee MPPT

    Two separate arrays, two solar charge controllers, both connected with short heavy leads directly to the same battery bank--Should work fine.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #14
    Re: Wellsee MPPT
    moorsb wrote: »
    I am feeding a 2nd array to the battery bank. I am trying to get 120amps into the battery bank.

    How full is the battery bank? Perhaps one unit has raised the voltage to the point where the second unit thinks the battery is charged.

    Test them separately when the battery is down a bit.
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #15
    Re: Wellsee MPPT

    I have added a TM2020 to the system. I am not sure at all if I have it programmed correctly. That is the worst manual and instruction for setup that I have ever seen. It is like someone translated the step by step and left out things like, why am I doing this what effect does this have on the system. To enter the mode where you enter the bank capacity I had to turn off loads to get its attention seemed like it was too busy calculating things to catch the keyboard strokes. At this point I the volt were set 14.3 amps 99 is that as high as it will go I have over 100a from pv.
    I will have to play with this before I believe any data. It shows the battery fully charged the MPPT is still charging. and the MPPT show the battery not fully charged. I am not sure what number to plug in for the bank capcity it say to enter half if you do not want to discharge them very much so I entered 600 amps
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #16
    Re: Wellsee MPPT

    They seem to be working. I have a 1.5 kva transformer on the output of the inverter. If I leave the inverter on over nite my tri metric tells me the battery is down to 85% full in the morning and it is full at night. I tried a 5 kva transformer on over nite and the battery is down to 50%
    I guess I should rewire the pump to 120 vac and kill the transformer.
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  • moorsb
    moorsb Solar Expert Posts: 38 ✭
    #17
    Re: Wellsee MPPT

    The TM 2020 looks like I need to reconfigure. It says it has met charge criteria yet it shows 10 amps going into the system with little load. The MPPT controllers one says the battery is full the other one says it is not so I guess just one is charging the bank once it gets to this level. I have rewired the pump to 120vac and taken out the transformers. I am setting up to run my xmas lights outside too. The lights are drawing 50 amps out of the battery. I have them on a timer for 4 hours. This morning the TM2020 showed down 210 amps. The solar panels were pumping 50 amps back in this morning and by 11:30 I was back at 100 percent according to TM2020 but I noticed 10 amps still be pumped into the bank with minimal load. So I guess I need to reprogram the TM2020?
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  • mikeo
    mikeo Solar Expert Posts: 386 ✭✭✭
    #18
    Re: Wellsee MPPT
    I noticed 10 amps still be pumped into the bank with minimal load. So I guess I need to reprogram the TM2020?
    I haven't followed this thread closely, but depending on your battery bank, it could draw 2 to 10 amps just to float it. I have forklift batteries, 940 amp hours and it takes 2 to 3 amps to float.
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  • Gulch
    Gulch Registered Users Posts: 13 ✭✭
    #19
    Re: Wellsee MPPT

    Hi Gang.

    I have one of the 24Vin 12Vout, 20 AMP ones, purchased direct from Welsee in China.

    First, the good news: Service was good, only took a week to get here.

    Had it in service for two days now, feeding a 400AH bank off of two Kyocera 205 watt 24V panels in parallel.

    Just using it to keep the batteries that run my lights and furnace blower in the RV topped off.

    It charges the batteries OK, but it is NOT MPPT (at least as far as my limited understanding of the concept goes), just as earlier posters have surmised. Amps out is slightly less than amps in, but since the voltage is just about halved, I'm losing about half the wattage that the panels put out.

    Here is a photo of two Watts Up meters showing what is going into and out of the Welsee controller. The top meter shows what is coming off the solar panel, the bottom shows what is going into the battery bank;

    (I have photos of the inside of the controller as well, if anyone is interested.)
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  • Gulch
    Gulch Registered Users Posts: 13 ✭✭
    #20
    Re: Wellsee MPPT

    By the way, even when the batteries are down to 12.0 volts the controller still puts out a fraction less than 1/2 the watts that are going into it. The batteries haven't gone below 12.0V since I got the controller, so I can't say definitively that there won't be a better efficiency throughput if the batteries are deeply discharged.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #21
    Re: Wellsee MPPT

    I think you have pretty much shown that the controller is, functionally, not a MPPT controller.

    If you want to post a picture of the internals--that would probably help.

    If there are no "big" inductors inside the unit--then it does not have the energy storage needed to do down conversion and perform MPPT.

    High current inductors are big and "expensive" and are usually the first thing to go in a "low cost" product.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Gulch
    Gulch Registered Users Posts: 13 ✭✭
    #22
    Re: Wellsee MPPT

    Nope, no big inductors, no toroid etc, just a simple widely spaced coil of about 12 ga wire.

    The simple controllers I used to mess with for brushed DC E-Bike motors were similar, in that the main solid state components were MOSFETS and Schottky diodes.but they were even more complex than this thing is.

    I'm halfway tempted to un-pot that 'black box' that says MPPT on it to see what sort of 'magic smoke' it may contain.

    A LOT of waste space in the box... the circuit only takes up about 1/5 of the volume. The ribbon wire in the photo goes to the three LEDs in the cover and the black and white wire goes to the reset button.

    I opened up a 30A Sunforce PWM controller I have laying around to compare, and the sunforce is a lot more complex, although it has fewer MOSFETS and Schottkys.

    Anyway, I am in the process of intentionally running down the batteries to see what the meters say when it is charging them up from about 11.5 V. I'll let y'all know what happens with that.
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  • Gulch
    Gulch Registered Users Posts: 13 ✭✭
    #23
    Re: Wellsee MPPT

    OK, I admit that I'm totally confused now. As I said above, I decided to run down the batteries so that they needed a heavy charge. I did so, down to 11.7V, and hooked everything back up.

    For a few minutes, the meters showed that about the controller was putting out about 49.90% of what was going into it, off of one panel (which was putting out about 7.2A @ 25V.... 31V Open circuit) Then, I hooked in the other panel in parallel, and the meter on the solar panel dropped down to 14.4 V at about 7 amps, with the meter between the controller and the batteries showing 13.2V at about 13 amps. (which would make sense, since the un-metered panel was putting out about 7 amps as well.

    THEN, I moved the meter from between the controller and the batteries to the unmetered solar panel.... a few moments later, both meters started 'gyrating' rapidly, showing that on both panels, individually, were putting out 16 to 26 volts at 4.5 to 6 amps each (V & A readouts changed every half second or so.)

    Then, I got out another meter (An EagleTree data logger that mostly the RC guys use) and put it in between the controller and the batteries, and IT showed a fairly stable 13.4 V @ 8.8 amps going into the batteries..... And I came in to type up this report....

    Now, ten minutes later, the meters on the panels seem to have stabilized, (without the rapid V and A swings), at about 26V and 4.5A each, and the meter on between the controller and batteries shows a stable12.99V @ 8.9A

    The volt meter I have 'on the other side' of the batteries is showing a stable 13.47 V.

    So, I can only conclude that either:
    A: I'm crazy AND stupid.
    B: The meters are all intermittently psychotic.
    C: The controller is crazy (I'm pretty sure the panels and the batteries are sane)
    D: The magic smoke inside the 'black box' labeled MPPT actually does do something that is beyond the obvious and beyond my limited understanding.

    Sorry for the tortured paragraphs.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #24
    Re: Wellsee MPPT

    Perhaps you have just proved that "Chinese junk" is more than just a type of boat. :p
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #25
    Re: Wellsee MPPT

    You may be seeing the controller turning on and off to either figure out how much charging the battery needs--or the beginning of the PWM (pulse width modulation) cycle...

    The PWM cycle may be 100's of Hz (more or less) or may be seconds (don't know)--In either case, as the battery gets charged, the controller will no longer be 100% on--but cycle on and off to reduce average current flow.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Gulch
    Gulch Registered Users Posts: 13 ✭✭
    #26
    Re: Wellsee MPPT
    BB. wrote: »
    The PWM cycle may be 100's of Hz (more or less) or may be seconds (don't know)--In either case, as the battery gets charged, the controller will no longer be 100% on--but cycle on and off to reduce average current flow.
    -Bill

    OK, Thanks.

    SO, Perhaps, as the controller tries to decide how much current it wants to draw, maybe the current surges make the meters think that they are seeing less voltage than the panel is actually putting out?

    The fluctuations on the panel meters was what really seems weird to me. I never saw anything like that on SOURCE side on the E-bikes that I built (which is where I used the meters before), even when I was 'blipping the throttle or under hard acceleration. (I am equating the PWM motor controllers that I used, with the charge controller; They seem very similar). Of course on the output side, I have seen the PWM fluctuations pretty regularly.

    AND on the original system I had on the RV, which was two 135Watt Kyoceras feeding a Xantrex C30 CC. The meters always stayed pretty stable with that setup....
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #27
    Re: Wellsee MPPT

    Silliness aside ...

    The PWM is like an on/off switch. When it's on and current is flowing to the battery, PV Voltage will come down (Vmp) and PV current will go up (Imp). When it's off, PV Voltage goes up (Voc) and current goes down. Now think of that switching on and off hundreds of times per second as Bill said. What do you think that will do to your meter readings? When the charge controller is in a "constant state" (all on for initial bulk charging for instance) the output readings from the array will be stable. When the charge is finished and the on/off switching slows for float maintenance the fluctuations at the PV will be slow and the meters will be able to "catch" accurate readings. The worst-case will be when the controller is trying to "pick" a pulse rate; PV output will bounce up and down like crazy.

    It's good to remember that PV's source current, not Voltage.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #28
    Re: Wellsee MPPT

    As Marc said... Solar panels are really current sources--and with a PWM controller you will see on the PV input side (during the day) typically one of two voltages... Either the voltage at the battery (controller on, max current flow) or Voc (Voltage open circuit when the controller is off, near zero current flow).

    So, you will see a step voltage and a step current (of opposite phase)... Depending how the digital meter is constructed, its sampling rate, etc.--It may get "seriously confused" when trying to measure the voltage and current wave forms and do the math for Watts/Amp*Hours/etc.).

    In digital systems theory, the minimum sampling frequency is called the Nyquist Rate (or Frequency).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Gulch
    Gulch Registered Users Posts: 13 ✭✭
    #29
    Re: Wellsee MPPT

    Thanks Bill and Marc. I begin to understand. Just because I didn't see it before in prior applications, doesn't mean it didn't happen. And throwing the supposed MPPT from the 'Chinese Junk' I couldn't quite grasp what I was seeing, or was supposed to see.

    I just put a different battery (which was down to 10.5V from sitting around the storage shedfor two years) on the system, , and the meters are going even more crazy than they did earlier.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #30
    Re: Wellsee MPPT

    imo, it isn't supposed to do that and if that's a pwm then it is at a rate of about 1/2hz or less to see the voltage climb like that. this is not good for charging and i think you should stick with reputable controllers.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #31
    Re: Wellsee MPPT

    Depending on the current rating of the array and controller, you might be seeing a form of over current limit.

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