Morningstar MPPT 60 Battery Sense

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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #62
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    Re: Morningstar MPPT 60 Battery Sense

    BTW, got an immediate response from somebody at M* after the Facebook post....go figure.
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #63
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    Re: Morningstar MPPT 60 Battery Sense

    Glen, it appears you have a very good system as it relates V drop, etc. As NorthGuy noted, you probably don't even need the battery sense line hooked up to your system. If you had no voltage drop anywhere, no need for a separate sense line. I am waiting for heavier cable to come in at a vendor down here. The simple things are difficult here. Can't just run to West Marine. However, if you go through the manual and read the section on the battery sense line, it is in the controller for exactly what we are discussing. In essence, making the controller blind to V drop on the charging circuit and regulating based solely on the voltage in the battery. It isn't doing that. The V drop is modulating the sense voltage and defeats the purpose of having it to begin with.

    Thanks for doing the checks. But with no V drop you won't see the problem as NorthGuy said.
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  • Muskoka
    Muskoka Solar Expert Posts: 103 ✭✭
    #64
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    Re: Morningstar MPPT 60 Battery Sense

    I'll try that next time myself. I've been waiting close to a week for a response to a support email as well. Thankfully I was able to figure it out for myself. Please report back, I've had these controllers for almost 4 years, and still haven't got them totally sorted out. They don't play nice together.

    Glen

    Edit: Posted at the same time, I get it now...ok, slow sometimes. I started with "little" wire, soon learned it really can never be too big, if you know what I mean, bigger is better, wallet permitting.
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #65
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    Re: Morningstar MPPT 60 Battery Sense
    svNorthStar wrote: »
    I am seeing a .3V voltage drop just measuring V across the negative charging terminal to the negative battery sense terminal. The actual reading is current dependent and higher current means higher drop. In other words my negative battery sense is a -.3V potential which is then skewing the battery sense reading the unit is working by that amount. Causing it regulate like the battery voltage is .3v higher than it really is. Undercharging....

    Just put your DVM across the negative battery sense terminal and the negative charging terminal and see if there is any drop.

    Is the voltage drop the same on both + and - charging wires? If it is not, then something is wrong on the - side other than just wire resistance. A bad termination, high resistance connection, etc.
    If the drop is the same on the + side, then you are losing .6 volts at charging current, which is, as others have said, far too high.
    SMA SB 3000, old BP panels.
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #66
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    Re: Morningstar MPPT 60 Battery Sense

    Glen ...the big challenge on a boat is space. We have bilges and chases full of cables as big as your thumb. If I was home, no problem with bigger is better. We were shooting for a < 3% drop, but had to go with one smaller size wire because that is all we can get and have no idea when it will arrive. Realizing were are losing some power to voltage drop loss, we were willing to accept that for the time being. The unit should still regulate properly based on the sense wires, but it isn't.
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  • Muskoka
    Muskoka Solar Expert Posts: 103 ✭✭
    #67
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    Re: Morningstar MPPT 60 Battery Sense

    Deleted my post, really getting confused here. I need to go back to the beginning and read it all again. Used to have a 23' sailboat myself, many years ago. No, not much space at all.

    Glen
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #68
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    Re: Morningstar MPPT 60 Battery Sense

    Glen... if you go back to post 18 in this thread I posted the relevant part from the manual. The way it is described in the manual it says there should be no voltage drop on the sense line because there is no current flow. That makes total sense, no current no drop. It then talks about V drop on the charging lines where there is current flow. Again makes total sense. The problem I am having is that the negative battery sense line is referencing off the negative charging line for some reason. In other words, it is not a separate circuit that monitors battery voltage, irrespective of what's happening on the charging lines. That is what it is supposed to do, but in my case doesn't. If you had not V drop on the charge lines then you wouldn't even need the battery sense lines they would be redundant. They put them in there supposedly to allow the controller to regulate properly in spite of a V drop on the charging lines.

    Hope that makes some sense because we have sure talked it to death. From here, I think I'm going to have to see what M* has to say.
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  • Muskoka
    Muskoka Solar Expert Posts: 103 ✭✭
    #69
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    Re: Morningstar MPPT 60 Battery Sense

    Starting to understand what's happening now, I think.

    To further something you said about my system. I don't have any voltage drop (hardly measurable). It was suggested I could remove the sense wires, that would be nice, less clutter. The problem is, without the sense wires, the controller uses the "Battery Terminal Voltage" (I think), then compensates for temperature, and adjusts the Target Voltage (Absorb) correctly. On both of my controllers the BTV is always at least a tenth high in MSView. It's not physically higher (from actual meter readings), but it's being falsely reported higher through the software. Your right in saying that something is not quite right, but I still think it's a logic / programming issue in the software itself.

    If I remove the sense wires, I would be in the same boat (no pun intended) as you. The system is falsely raising the Target Voltage (Absorb) point, and will be going through Absorb and on to Float long before it should, and my batteries would see a slow inevitable under charged death. Hopefully folks check their sg so it never gets to that point, but it sure could if the system is incorrectly raising voltage setpoints.

    The temperature compensation works properly, but only because I'm using the sense wires. If I remove the sense wires, my Absorb will be at least a 1/10 too high, before temperature compensation voltages are even calculated. In reality, it's not that much of a difference, 1/10th, I just wish it wasn't so wishy/washy, and reported everything correctly. It makes you wonder what else may be going on.

    Glen
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #70
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    Re: Morningstar MPPT 60 Battery Sense

    Glen...I think you've got it now. You are seeing the same thing I am, just to a much less degree. You have around a 1% voltage drop, I have 3 to 4 times that amount. You're seeing your battery sense value about .1 volt high, me about 3 to 4 times that amount. See the pattern. I wouldn't remove the sense wires if I were you. I was just trying to make a point. If you start to see an unusual for your system differential there it would indicate something amiss. Some corrosion in a connection or whatever. Anyway, had I seen only a .1 V max difference I never would have mentioned it. That would mean your system would actually kick into absorption a .1V before it should. Not a big deal, but for me kicking in at 13.8 when set for 14.2V not nearly close enough.

    All that being said, if the battery sense worked as advertised, then it wouldn't matter because the battery sense would compensate. Which it doesn't now.
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  • tangk1
    tangk1 Registered Users Posts: 4 ✭
    #71
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    Re: Morningstar MPPT 60 Battery Sense

    Firstly, Tristar MPPT and PWM's battery sense ports have PCB design problem. The two little voltage sense ports (+ / - ) should be placed to different locations and more far away. It can be short circuit the battery by mistake. I believe that many people in the world have not put fuse or MCB series to the battery sense ports. It can cause fire when there is a short circuit in 1-2mm short ports distance.

    I personally think that Battery sense ports are useless. As we know that the resistance of the Thick Battery power cable is much smaller than the one thin cheap cable used for battery sense. Even we add the MCB or fuse series to the battery cable. The voltage reading getting from battery ports may be more accurate. If it is true, why Tristar should not just patch the wire inside the PCB and "T" into battery ports , but now suggest the user to patch by itself.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #72
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    Re: Morningstar MPPT 60 Battery Sense
    tangk1 wrote: »
    Firstly, Tristar MPPT and PWM's battery sense ports have PCB design problem. The two little voltage sense ports (+ / - ) should be placed to different locations and more far away. It can be short circuit the battery by mistake. I believe that many people in the world have not put fuse or MCB series to the battery sense ports. It can cause fire when there is a short circuit in 1-2mm short ports distance.

    I personally think that Battery sense ports are useless. As we know that the resistance of the Thick Battery power cable is much smaller than the one thin cheap cable used for battery sense. Even we add the MCB or fuse series to the battery cable. The voltage reading getting from battery ports may be more accurate. If it is true, why Tristar should not just patch the wire inside the PCB and "T" into battery ports , but now suggest the user to patch by itself.

    the difference is a dmm will use 12v/11,000,000ohms=1.1 microamps and is not pulling the voltage down via voltage drops on a separate wire even though it's small. to measure off of the big wire means the 1.1ua + the current drawn over the larger wire and then figured for voltage drops giving a false voltage.
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  • smatthew
    smatthew Registered Users Posts: 15 ✭
    #73
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    Re: Morningstar MPPT 60 Battery Sense
    tangk1 wrote: »
    I personally think that Battery sense ports are useless. As we know that the resistance of the Thick Battery power cable is much smaller than the one thin cheap cable used for battery sense. Even we add the MCB or fuse series to the battery cable. The voltage reading getting from battery ports may be more accurate. If it is true, why Tristar should not just patch the wire inside the PCB and "T" into battery ports , but now suggest the user to patch by itself.

    The resistance of the "thick battery cable" may be less than the sense wires, but voltage drop is dependent on the amount of current being passed. Since measuring the voltage takes basically no power, there is basically no voltage drop. The battery cable is passing many amps, and does suffer from voltage drop.
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #74
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    Re: Morningstar MPPT 60 Battery Sense

    tangk1....I would agree that the sense terminals should be further apart. There is a danger of accidentally short them with just a few mm between them. You need to make sure you have the other ends disconnected before making the connection in the controller. Not sure why you think the battery sense port would be useless, if it worked the way it's supposed to work I think it is an excellent idea. You will have false (in the sense of being affected by the voltage drop) battery readings on the Battery Terminal lines (charging lines) Yes, they are bigger, but passing a lot of current and incurring some level of voltage drop that the controller shouldn't be basing it's decisions on.

    Are you saying that Morningstar has suggested you patch the controller yourself? I'd love to hear more about that?
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  • Muskoka
    Muskoka Solar Expert Posts: 103 ✭✭
    #75
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    Re: Morningstar MPPT 60 Battery Sense

    I have taken the sense wires off both my controllers to see what happens today. I'm home all the time so I can monitor closely what's happening. The first thing I noticed is all the battery voltage readings in the controller meters, and MSView, are at minimum 1/10th a volt higher than battery bank actual. This is with no load, no charge. I'll let you know how the controllers react with regards to voltages as soon as the sun starts it's magic. It's a perfectly clear cool day here, perfect conditions.

    Another thing I'm noticing, the BTV (Battery Terminal Voltage) which used to be at least 1/10th a volt higher than all other readings with the sense wires installed, is now almost perfectly in-line with all the others. The reported voltages are also a lot less erratic, they're all within 1-2 /100ths, where before they would sometimes jump up or down by a 1/10 or more.

    Glen
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #76
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    Re: Morningstar MPPT 60 Battery Sense

    I'll be interested to see what you come up with. I bet everything will work perfectly fine for you with tiny voltage drop you have.
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  • Muskoka
    Muskoka Solar Expert Posts: 103 ✭✭
    #77
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    Re: Morningstar MPPT 60 Battery Sense

    Well, everything started out well, then the clouds showed up till noon. I'm still really fighting an uphill battle trying to co-ordinated 2 different controllers so it's hard to test. Their both Morningstar units, one MPPT, the other is PWM. They do not play nice together at all. The MPPT goes to Float fine, the PWM just wants to keep chugging along. The MPPT went to float today around lunch, and a hour later the PWM was still in "PWM" mode. I've set the Absorb voltage lower on that controller so it will finish first, no luck. I set the "Duty Cycle" timer a half hour less than the timer on the MPPT unit, still no luck. It just doesn't like going to Float. The batteries were full, 1.270 sg across the board. I have close to 50 amps charge current on that controller, with 10 amp loads. It should have no problem going to float. In reality, you should be able to set the controller to your battery manufacturer specs and be done with it. Well that works for the MPPT controller, but doesn't for the PWM. I have less potential current on the MPPT controller than the PWM, and it has no problem going to Float, it doesn't make sense.

    I ended up putting the sense wires back on. With them off, the controller was inflating the actual voltage too much for my liking, I don't want that. I rather have the controller set the voltage a little lower than battery actual, if anything at all, then I know the batteries are getting a good charge. As soon as I put the sense wires back on the voltage sorted itself out, and was the same as the actual battery or a little lower. When the sun finally came out and things got cooking, all the voltage readings in the controller were at least a half to a full volt higher than the actual battery. I remember at on point the actual battery was 13.8v, and the controller readings were 14.8v. Once it got deeper into Absorb the voltages started to become more in line with the actual battery readings.

    Sorry I can't give you something more concrete, and getting off track a bit, I'm becoming frustrated with this PWM controller and needed to rant. I think when my MidNite Classic shows up, the PWM Morningstar is going to be retired.

    Glen
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #78
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    Re: Morningstar MPPT 60 Battery Sense

    Sorry it didn't work out better where you could get some more meaningful data. Yes, without the sense wires, yours is acting more like mine does with the sense wire. Have you ever calculated your actual V drop on your charging lines at max current flow? Can't imagine trying to get two of these things balanced, especially when they are chasing phantom numbers that are incorrect.

    Have heard from customer service at M*, will let you know how that goes.
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  • Muskoka
    Muskoka Solar Expert Posts: 103 ✭✭
    #79
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    Re: Morningstar MPPT 60 Battery Sense

    I don't have any measurable voltage drop. I can measure anywhere I like in my system, and get the same voltage readings within a couple 1/100ths. The only discrepancies I have with voltage, is what the controller displays.

    Right now in MSView:

    Battery Voltage = 13.77v
    Battery Terminal Voltage = 13.84v
    Battery Sense Voltage = 13.75v
    Target Regulation Voltage = 14.97v

    Absorb set point is 14.7v
    Temperature Compensation right now = (+).28v

    Actual Battery Voltage = 13.73v

    The Target Regulation Voltage (Temperature Compensated) is right on, usually is, and the Sense wire Voltage is only 2/100ths off the actual reading, so no issue there.

    These numbers are very good, but the system is just barley covering the loads, it's pretty cloudy. When it's gets going the discrepancies in the numbers are much greater, but the Target Voltage is usually pretty close. It's the reported Terminal Voltage that's always off, I don't know why, but it doesn't really matter as long as I get to my temperature compensated Target Voltage which always seems to be close to what it should be.

    Glen
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #80
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    Re: Morningstar MPPT 60 Battery Sense

    Your numbers are excellent. Some day I hope to have unmeasurable voltage drops in my system. ;)

    I'm told my cable is in Panama at customs. Nobody seems to know where the lugs and other connectors I ordered are presently. But, hopefully they will turn up.

    I was playing around MSView and although quirky, can give you nice data out. I put together a little spreadsheet to take the data from it and present it so I can look at everything relative to each other. I think I like it, although I have a few more tweaks. It's a little busy. Volts scale on left amps on right. The green triangles are actual measurements taken with my DVM at the battery sense terminals inside the controller, at the same time as what was output by MSView. As you can see, everything starts off as it should and as the current gets higher the discrepancy gets worse between Battery Logged and the actual readings on the Battery Sense terminals in the unit.


    Attachment not found.
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  • Jakachira
    Jakachira Solar Expert Posts: 47 ✭✭
    #81
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    Re: Morningstar MPPT 60 Battery Sense

    Guys, I have just got myself a new Morningstar TS-MPPT-60. Impressive unit.
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  • svNorthStar
    svNorthStar Solar Expert Posts: 47 ✭
    #82
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    Re: Morningstar MPPT 60 Battery Sense

    Yes, I think the M* MPPT-60 is a well made unit. It works well as long as you don't have any significant voltage drop on the charge lines. There is battery sense line that is supposed to fix that, but doesn't really work at least in my unit. As amperage flow increases the battery sense voltage departs from reality and follows the higher charging voltage upward which then causes inaccuracies in the unit regulating properly. You can see the graph I posted prior for an example. However, it is better to just eliminate the Vdrop and eliminate the problem all together. Plus.......who wants to waste this expensive electricity heating up some wires.
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  • sanitariu
    sanitariu Solar Expert Posts: 33 ✭✭
    #83
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    Re: Morningstar MPPT 60 Battery Sense

    svNorthStar any news from M* ?
    I have MPPT 45 controller and suspect similar problem.
    I am staying at absorption time for 300-340 minutes and almost never go to float.
    4 X 240watt Luxor, Victron Energy Multiplus Compact 24 volt 1200VA, electrodacus solar controller, 8 x WB-LYP160AHA LiFeYPO4 3.2volt
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #84
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    Re: Morningstar MPPT 60 Battery Sense
    svNorthStar wrote: »
    Yes, I think the M* MPPT-60 is a well made unit. It works well as long as you don't have any significant voltage drop on the charge lines. There is battery sense line that is supposed to fix that, but doesn't really work at least in my unit. As amperage flow increases the battery sense voltage departs from reality and follows the higher charging voltage upward which then causes inaccuracies in the unit regulating properly. You can see the graph I posted prior for an example. However, it is better to just eliminate the Vdrop and eliminate the problem all together. Plus.......who wants to waste this expensive electricity heating up some wires.

    If the Morningstar unit's battery sense line problem is one discussed earlier in another thread, the "corrected" voltage measured will be the difference between the + sense lead and the - charge lead. The - sense lead is just ignored. So if you want to minimize your wiring cost, just use bigger wire on the - side.
    SMA SB 3000, old BP panels.
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  • MGar
    MGar Registered Users Posts: 14 ✭✭
    #85
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    And that's why you should always check, the battery is not charged...
    I have same problem with the "voltage sense" on the Tristar MPPT60 jumping like a ping pong ball in MSView and at ChargeController screen.
    But shows steady in the "Battery Voltage" web app. and the CC.
    The XW is steady and costs a lot less in the parallel stet-ups.

    They don't say to use a resistor or a ferite bead, some thing to try..
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