Phantom Drain?

Gentlemen:
I live in a small RV (presently in the Quartzsite, AZ area) with the following solar and electrical equipment:
3 120-watt Kyocera panels, roof mounted and tilted to the south.
4 AGM 12-volt 100-amp batteries
1 2000-watt Heart Inverter, modified sine-wave.
1 Solar Boost 2000E controller
1 Link 1000 battery monitor and inverter switch.

All of the above have been professionally installed. Now, to my problem:

I had been running off of battery power. Normally before I turn the A/C on I put us on the power grid. Well, I forgot and turned the A/C on. It was only on for perhaps a minute before I realized my error and put us on the power grid. Ever since then, we’ve had a problem with our battery voltage.

Under full solar input, the battery power won’t come up to normal. We’ve had full sun all day, and started off about 60 amp/hrs down. Ordinarily I can expect the batteries to be completely charged in the early afternoon, drawing in about 18 amp/hr in the peak time (from 1000 to 1400) . It is early afternoon now and the battery voltage is still around 12.25. My batteries are connected in parallel, and I did not unhook anything before I measured the voltage, if that matters. I did measure the voltage at each battery post, and they’re all the same. The Link 1000 indicates that we’ve recovered 54 amps, so we’re only 6 amps down. The battery voltage should have been up around 14 volts at this time instead of only 12.25.

We’re currently on the power grid and will stay there until the solar system problem gets resolved. The other curious thing is that it looks like I now have a small, constant current drain (around 3 amps or so). I’ve double checked everything that runs off of 12V power (lights, fans, etc) and nothing is on.

The exact current drain when there’s no solar coming in is 2.8amps/hr. the voltage right now when there’s no solar coming in is 11.85. The Link 1000 measures –5.5 amp/hrs down right now.

Is it possible that short burst of energy that the RV air conditioner took screwed up one or more of my AGMs? They're 3 years old and are the Lifeline brand. They've never been taken below 50%.

Can anyone give me a clue about what is going on? I have a VOM and can measure voltages and current. I’m reasonably familiar with most of the solar components, and understand (and sometimes even follow) logical trouble-shooting steps.

-silverjim-

Comments

  • BB.BB. Posts: 27,698Super Moderators admin
    Re: Phantom Drain?

    Check if the current drain is real (sounds like it probably is)... If you have a shunt, place your volt meter on a low range (xxx mVolts, or 1-2 volt DC range) and see if you measure a voltage across the shut (it will probably something like 100mV=100 amps or 100mV=500amps or something like that).

    You should ensure that each load is turned off normally, then disconnect one fuse/breaker/wire at a time until you find where the phantom load is coming from.

    Even if you have a bad battery, the phantom load current you are seeing should be coming from the battery and going else where (inverter, DC loads, Solar Charger, etc.)... The Battery Monitor should not be able to "see" a battery self discharging as current (you would only notice a problem with voltage dropping over time, or problems achieving full voltage).

    One other slight possibility is that the momentary heavy load of the A/C overheated a loose and/or dirty connection point (or corroded cable, overheated a current shunt, etc.)... With current flowing (either as a good sized load and/or AC charging) use a millivolt meter to measure the voltage drop at each connection (you can also try to feel for any warm spots and/or melted insulation).

    But I would try and find/fix the phantom load first...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    Thanks for the advice, BB. I cracked the fuse panel to the RV and pulled each DC fuse, checking the Link 1000 each time to see if the phantom load was still there. Yep, I went through every DC fuse and the phantom load is still there. There is some buildup on the negative terminal of one of the AGM batteries, so I'll fuss with that tomorrow. That's the only trace of corrosion I can see.

    -silverjim-
  • nielniel Posts: 10,311Solar Expert ✭✭✭✭
    Re: Phantom Drain?

    disconnect the inverter and see if the drain stops. that burst of power the ac needed could've been too much for the inverter and screwed it up. if the drain stops with the inverter out of line you've found your problem. if the drain continues you must take the batteries out of line untill the drain is located as 10.5v is 100% dod or in layman's terms, dead.
  • BB.BB. Posts: 27,698Super Moderators admin
    Re: Phantom Drain?

    If the A/C + Inverter current draw exceeds the rating of the Link 1000, it is possible that the Link 1000 was damaged--However, looking at the Link 1000 specs, that is supposed to be a 500 amp 50 mV shunt--that would be a 5+ kWatt load. Doesn't sound like that you had that problem.

    I would check the leads to the shunt and Link 1000 and make sure that they are clean and tight. To read several amps accurately, the shunt would be only showing 0.2 to 0.3 mVolts--a pretty small voltage to accurately measure. You could try swapping the current sense leads (+ and -) on the back of the link 1000 and see if the polarity of the current changes--if it does, there is probably current flowing... If it does not (or still shows current when the shunt leads are disconnected), then there is a probably problem with the Link 1000 itself.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • crewzercrewzer Posts: 1,832Registered Users, Solar Expert ✭✭✭✭
    Re: Phantom Drain?

    Silverjim,

    Frankly, I’m impressed that the 12 V x 400 Ah battery bank and the Heart 2000 inverter were able to start and sustain the RV’s air conditioner. However, it’s possible that the sudden DC current draw (> 200 A?) by the inverter caused the battery bank’s voltage to briefly drop below 8 V, and that may have upset the Link 1000. This voltage drop may have been too short for the inverter’s low battery voltage protection to kick in.

    I recommend you completely power down the Link 1000 for a few minutes, reconnect it and see what happens.

    HTH,
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    This morning the batteries were completely dead, like in 9V measured at the battery terminals. After the sun was up for about an hour things started getting enough juice to operate. I was even able to turn our refrigerator back on after a while.

    I disconnected the positive lead from the Heart to the batteries (at the catastrophic fuse), figuring that would disconnect the inverter, and then checked the current drain. Damn, it's still there.

    After I got enough of a battery current to power the Link 1000 back up, I turned the charger on (after making sure it's set for AGM batteries). The charger only ran for a few minutes before the 25amp fuse on it popped out, telling me that it had an overload or high temperature condition. When the charger was running the Link 1000 indicated around 85 amps coming in.

    I used the battery disconnect switch to cut off all DC voltage to the coach. Nope, the drain is still there.

    Could the problem indeed be one of the batteries? It's giving me a slow short circuit or some such? How would I test for a bad AGM battery? All the tests I've been able to find seem to want the battery to be fully charged first. I can't get the damned batteries to be fully charged.

    I do have a little automotive-type charger, if that helps. I called an RV guy to come around and hook up our converter so that the AC can keep the batteries charged (hoping that the solar installer didn't just snip the wires of the converter).

    Are we having fun yet? Any ideas appreciated, with deep gratitude for the advise already offered.


  • BrockBrock Posts: 629Solar Expert ✭✭✭
    Re: Phantom Drain?

    I am confused. If you disconnect all the loads from the batteries how do you know there is still a load? You would have to have something connected to the batteries to have a load. I would start by disconnecting everything and I mean everything from the batteries and then charge them by themselves with an external charger and see how they react. That would rule them out as the problem, or prove one of them is the problem. My guess is either the charge controller or inverter has somehow failed and is sucking power all the time. I really thought Jim nailed it with the controller being confused and that would have been my first guess, that the controller was either confused and not charging correctly or somehow failed and drawing extra power.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    I powered down the Link 1000, waited for a few minutes, then powered it back up. There's no discernible difference, unfortunately. I'm still getting a phantom draw from some place. The Link 1000 indicates my battery voltage right now as 11.70, verified with my VOM at the battery terminal. My solar amps coming in right now is 20.2, indicated at the Solar Boost.

    Brock indicated that the charge controller might be at fault. How would one test the Solar Boost?

    It would seem unreasonable to me that a 3.0 amp drain during the night could have possibly drained the batteries clear down. I've made an appointment with a very good solar installer in Quartzsite for Monday, but I want to keep chasing that problem until then. Who knows, I might even cover myself with glory by fixing it myself, with the aid of you folks.

  • crewzercrewzer Posts: 1,832Registered Users, Solar Expert ✭✭✭✭
    Re: Phantom Drain?
    How would one test the Solar Boost?

    There's a relay inside the SB2000 that's supposed to open at night to keep the batteries from discharging through the PV array. Normally, you should hear the relay click when it closes in the morning and then again when it opens in the late afternoon.

    I'd let the SB2000 keep charging the batteries today to get them back up to some decent voltage. Around sundown, try disconnecting all DC loads and connections again (including the fridge, LP leak detector, etc.) and see what happens. The Link 10 and SB2000 should be very small loads.

    If you've still got a 3 A discharge, then try disconnecting the + line between the SB controller and the batteries (or pull the in-line fuse). If the discharge drops to near zero, then something in the SB would appear to be the problem. If so, you could narrow it down further by reconnecting the + line (which should cause the discharge current to rise), and then disconnect the PV+ input line to the controller. If the discharge current drops again, I'd suspect the SB's internal PV connect relay is stuck closed.  :-(

    If the relay is stuck closed, you'll need to manually disconnect the PV array in the late afternoon to avoid the discharge, and then reconnect the array each morning. You'll also need to look into a controller repair or replacement.

    I really HTH,
    Jim / crewzer
  • BrockBrock Posts: 629Solar Expert ✭✭✭
    Re: Phantom Drain?

    HTH?
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • crewzercrewzer Posts: 1,832Registered Users, Solar Expert ✭✭✭✭
    Re: Phantom Drain?

    Hope This Helps
  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    Just to bring y'all up to date:

    The converter is now humming away, gently charging the batteries up. A combination of the solar panels and converter charging is pushing in 19 amps right now resulting in a voltage reading of 12.45. We distinctly remember hearing the relay click in the Solar Boost, but I'll do the checks tonight anyway. I'd read that thing about the relay a long time ago, but (like so many other things) it's faded away in the dim mists of ebbing memory.

    I've an appointment with Discount Solar in Quartzsite next Monday, if I can't figure things out by then. The relay thing, to me, is the most logical thing right now. Since the converter is working now, that assures me we'll at least be able to pull our slideouts in and bring our jacks up to make the appointment and to keep our refrigerator going until then. Odd that, even though the fridge functions on propane, it requires some 12-volt to run the little circuit board.

    -silverjim-
  • BB.BB. Posts: 27,698Super Moderators admin
    Re: Phantom Drain?

    You will have to disconnect "All Loads" one at a time to figure out where the discharge is... Disconnecting all of the DC distribution fuses must not have the only connections... The inverter, Link 1000, AC Charger, and Solar Charger probably either go through their own large amperage fuses, or, possibly, even directly to the battery (really need a fuse or fuse-able link for safety in every distribution wire/cable).

    There, I guess, a possibility that you could have one or two cells shorted internally in one of your batteries--unlikely, but to test, charge the batteries up and disconnect their main terminals (at least one on each battery so that they are isolated). If you have a battery with a failed/shorted cell, you should see one battery at least 2 volts lower than any other battery (you could put some sort of load on each battery as you measure the voltages to make sure there is not a "surface charge" on the bad battery.

    But even in the case of a shorted battery, you will not read a phantom load on the Link 1000. Also, use the AC charger to get the batteries fully charged again--leaving them mostly discharged for a few days or longer, will probably damage them in the long term.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • crewzercrewzer Posts: 1,832Registered Users, Solar Expert ✭✭✭✭
    Re: Phantom Drain?
    A combination of the solar panels and converter charging is pushing in 19 amps right now resulting in a voltage reading of 12.45.

    That's encouraging, but your batteries have a way to go... they should get to ~14.4 V (ref 77 F) for the absorption stage.
    But even in the case of a shorted battery, you will not read a phantom load on the Link 1000.

    I agree.

    Standing by for updates... this %&#!!@$$&;*#$ long distance diagnostics can indeed be frustrating! :x
    Jim / crewzer

  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    I was getting a bit discouraged at the minimal voltage gain until I realized a little while back that since my batteries have a capacity of approximately 400amps, that bringing them from essentially 0 at the piddly rate of 20 amps or so an hour is going to take quite a while. The while is probably going to be measured in days.

    This whole experience has broadened my solar trouble-shooting skills a little, which is one good thing I've gotten from this whole wretched problem. I'll be sure and keep you guys updated. By the way, if the SB2000 is fried, what would you recommend as a replacement? I'd prefer something with an LCD readout on it, as I do like to monitor things.

  • nielniel Posts: 10,311Solar Expert ✭✭✭✭
    Re: Phantom Drain?

    i wish you luck on isolating the problem, but there's one big problem now in addition to the cause of the drain, if they weren't the same problem to begin with. your batteries were drawn down to 9v. 10.5v is considered dead and you even went beyond that. if your batteries were fine in the first place, they aren't now. this, i can guarantee, took much of the lifespan away from your batteries. now i feel like a doctor with the relative of the patient asking 'how long does he got?' that's tough to answer as it could be next month, next year or even longer. who knows for sure? one thing you will have now learned is that if you have a drain that is unexplained you must disconnect everything by pulling the batteries out of line to stop the draining of the battery power until you can determine the source of the drain by connecting things one by one. when things go wrong it can be costly, just like when my ss10l blew when my charger's transformer failed and allowed 110vac to the controller. failures don't usually occur like this, but they can.
  • crewzercrewzer Posts: 1,832Registered Users, Solar Expert ✭✭✭✭
    Re: Phantom Drain?
    if the SB2000 is fried, what would you recommend as a replacement? I'd prefer something with an LCD readout on it, as I do like to monitor things.

    Silverjim,

    At 360 W STC, your PV array’s size makes it a toss-up with respect to economically justifying an MPPT controller. Additionally, the generally warm to hot ambient temperatures of your SW Arizona location will reduce the array’s output voltage, especially during the peak energy production time of ~10 AM to ~2 PM, so there’s likely to be any “extra” PV voltage to convert to any significant additional charge current anyway. This situation pretty much dilutes any technical justification.

    In sum, while an MPPT controller does work in your location, I doubt that you’re realizing any significant benefit from it. And, an MPPT controller is fundamentally of no benefit while it’s in absorb-, float-, or equalization mode because, while operating in such a constant voltage mode, the output current is limited or even declining.

    Don’t get me wrong, as I like MPPT controllers. It’s just my view that they make sense for large systems, and especially ones in locations that are fairly cold during the day at least part of the year, as the “extra” voltage from a cold PV array can be turned into additional charge current.

    Accordingly, you might want to look at the Morningstar ProStar 30M and the TriStar 45 with its optional display. Both include charger settings for AGM batteries, and I like the battery voltage sense feature. You’ll need the optional remote battery temperature sensor with either. Technical details and the user manuals are available from: http://www.morningstarcorp.com/

    HTH,
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    Thanks for the suggestion on a different controller. I'll have to ponder that some and poke around the net.

    I did the check of the Link 1000 as BB suggested. I disconnected the two shunt wires. No current registered on the 1000, so I'd assume I can rule that out. Or did he mean there shouldn't be any current on the shunt itself once the two Link 1000 shunt wires was disconnected?

    Another curious thing popped up. It used to be a fairly small voltage discrepancy reading between the Link 1000 and the Solar Boost (in the neighborhood of .25 volts or so). Now the difference is up to 1 full volt. Right now the Link 1000 reads 13.20, while the SB reads 14.3. Also, there used to be a fair difference between the current reading of the SB boost and the solar panel current, and now there is practically none (around .3 amps now, used to be more than 1 amp). Yeah, it's 73 out and probably warmer on the roof, but I've gotten used to seeing a bigger discrepancy than that between the two. What has usually happened in the past is that I would get three current readings, all different. The lowest one would be the panel current from the SB reading, then the middle would be the current from the Link 1000, and the highest would be the solar boost reading from the SB.

    I wonder if I've actually got two problems. At least one bad cell in the batteries (they don't seem to hold a charge all that well) and the much-debated 3amp drain. I'm sure getting tired of this crap.

  • BB.BB. Posts: 27,698Super Moderators admin
    Re: Phantom Drain?

    I was suggesting that if the Link 1000 read zero amps when the shunt wires were disconnected, then the meter was probably reading correctly (there was a phantom current drain).

    Well, you probably have a ~3 amp current drain and now, because you took the batteries flat, they are now kaput too (as reliable energy storage devices).

    It is not unusual for meters to have different readings from each other... For example, the Link 1000 documentation suggested that it used a 500 amp shunt... To expect much more than 1% accuracy (+/- 5 amps) is probably a bit much to expect. There are also calibration issues (another thread here about trying to find out what problems he had with his solar system and it turned out his expensive Fluke meter was damaged when subjected earlier to a damaging over-range current--but it read accurately enough to seem like it was working)...

    Lastly, you can have different voltage readings because of voltage drop... For example, if you are discharging a battery, measuring right at the battery posts will give a higher reading than 10' away at the load (say an electric water pump)... The higher the current/smaller gauge the wire--the more voltage drop (See Niel's copper wire voltage drop calculation spread sheet to experiment).

    And for current, depending on where in the circuit you measure the current, you may see different results (example: solar panel puts in 10 amps, 3 amp phantom load (like a bad inverter input), shows 7 amps going into batteries)...

    My suggestion, find the phantom load first--fix it, then look into purchasing new batteries--if you buy new batteries first, and then fix the phantom load later, you will probably end up killing the new batteries too...

    So, go back and disconnect all loads and use a small 12 volt automotive bulb--don't use too large a bulb or you won't see it glow for lower current "leaks" (or your DMM meter set to current if you KNOW that it is less than the maximum range for the meter so that you don't damage it), and connect each wire/fuse until the bulb starts to glow (I would suggest a bulb of a few watts or less for the test)... Assuming that the loads are all turned off--the one that shows current flow is the phantom load circuit/device.

    At this point, you cannot really trust anything--You may wish to purchase a "cheap" DMM (Digital Multifunction-volt/amp Meter) to verify everything you measure.

    Good Luck!

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Phantom Drain?

    Bill is right! You MUST, BEFORE ALL ELSE, find that "phantom" load and either fix it, or remove it, otherwise, everything is down the tubes. Once that is taken care of, THEN you can start to rebuild your system and think about the future.
    Wish I was there, could probably track it down for you in 5 minutes or less, as could most of these guys.
    Good luck
    Wayne
  • BB.BB. Posts: 27,698Super Moderators admin
    Re: Phantom Drain?

    And I should probably be clear on the shunt... If you are not aware of it, the shunt is just a precision resistor R=V/I=0.050volts/500amps=0.0001ohms (50 millivolt at 500 amps for the big shunts). The two heavy gauge wires carry the actual current flow, and the two small wires are where you attach a precision volt meter to measure the voltage drop.

    Disconnecting one (or both) of the two large wires connected to the shunt will stop the current flow, disconnecting one or both of the small wires will simply disconnect the Link 1000's voltmeter (but still leave the loads connected).

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