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mikakuja's avatar
mikakuja
Explorer
Sep 12, 2016

New Cruiser MPG 2400BH battery draw issues...

So we recently purchased a new 2016 Cruiser MPG 2400BH trailer...... And the fun begins, first day home and the batteries are so low that the awning will barely move. Figuring that the dealership forgot to charge the new dual 6v 210ah Interstate batteries I plug it in. after a few days I check the trailer and everything seems ok. later that week I install a 260 watt solar system with a remote display, transfer switch and 1500 watt inverter. Now things all seem good as the batteries have been charging all week and both the inverter and solar displays read fully charged. A week later we load the trailer and head out on our first 6 day trip in the new unit.
I should mention that this is our third trailer running a dual 6v battery setups. The solar and inverter setup were transferred from our previous rv and had no issues keeping our batteries topped up during days off grid camping with the family charging every conceivable electronic device.
First day in camp all seems good until we are wakened by the low voltage alarm going off on the co detector and inverter. Day two consisted of running the generator a total of 6hrs and full sun hitting the panels peaking at about 14.5 amps peak. Evening hits and we are not fully charged but above 90 percent which I figure will be more that ample power...... Nope wrong again... roughly 4am and low voltage alarms going off again, and so on for the rest of the trip.
We pretty much tried every form of power saving that we could think of with no positive results...
As soon as we arrived home the batteries were removed and taken in for testing... Next day I returned to the dealership and they replaced the batteries with two new 225ah batteries. Figuring the problem was solved I installed the batteries, made sure they were fully charged and headed out the next week for another week of camping.. While marginally better we found we still couldn't make it through a night without the batteries dropping to 12-12.2 volts by morning, without the furnace running... Running the furnace minimally would only insure the alarms would go off between 3 and 4 am...
Week number 2 I am now angry, and I have another three day trip planned and no time to look for problems.. Yup those three days all with low batteries in the am. I could not run the furnace at all during the night without the batteries being completely depleted even with solar and as much generator time as I could get during the day...
So now I am home and the trailer is going to go back to the dealership for testing and repairs. But not before a little investigative work of my own.
What I did find out so far is that the difference in power between the charge controller and batteries is roughly .8vdc when charging.
When the furnace is being run or the slide or awning are being operated the voltage reading on my charge controller drops to 11.8 -11.9 volts even when the batteries are near fully charged.
Any use of the furnace basically sets off the low voltage alarm on the CO detector if the batteries are anything under 90% charge.
I have also found that there is a condensation heat strip on my fridge that can't be turned off that is always drawing power... What a stupid frickin idea that is..
I am also assuming that the wiring is not adequate to run the trailer without running into a low voltage situation whenever running higher draw items...

Anyway, this is getting long winded so I will stop for now.
I am going to pick up a proper multi meter for measuring draw sometime this week and will post my results.

Any other ideas or suggestions of things to check would be greatly appreciated..

Thanks
  • cmeade's avatar
    cmeade
    Explorer
    Sep 12, 2016
    You are veteran rvers so maybe I should probably not mention fridge on auto defaults to AC voltage from your inverter and water heater on AC draws your battery down . Have you shut off your inverter and see if battery life increases???
  • bobndot's avatar
    bobndot
    Explorer II
    Sep 12, 2016
    How is the solar wired ?

    When i was running solar, i installed specific outlets in a different color that was dedicated to the solar line only.

    If all was charged up and ok for 6 days while sitting idle , then you set out for a trip, im assuming you turned the fridge on when you packed for that trip.

    x2....I would have to agree , the first thing i would look at is the fridge/inverter in auto mode as a possibility.
  • JFNM's avatar
    JFNM
    Explorer
    Sep 12, 2016
    I'm a fan of data. When you go to bed, how many amps is the house drawing from the battery bank? What is actually running? How about during the day?
  • SoundGuy's avatar
    SoundGuy
    Explorer
    Sep 12, 2016
    mikakuja wrote:
    I have also found that there is a condensation heat strip on my fridge that can't be turned off that is always drawing power... What a stupid frickin idea that is..


    You haven't mentioned just which fridge you have but based on this "stupid frickin idea" comment I'd guess it's a Dometic DM2652, the same fridge I have, with the same issue. It's a simple enough problem to solve - just wire in an SPST switch yourself that you can use to turn off that climate control heating element those times you're dry camping.



    FWIW, any documentation I've been able to find for this fridge indicates there is a switch to turn off this circuit but having pulled my own fridge apart and can say absolutely there is no factory installed switch on mine.

    As far as drawing down your batteries is concerned it would seem your next step would be to install an ammeter in the positive battery cable feeding the trailer to look for any unusual draw down, and if found start serching for the source of the problem by disconnecting everything, then reconnecting each 12 vdc circuit one at a time until you find the source of that excessive draw down on the batteries.
  • westend's avatar
    westend
    Explorer
    Sep 12, 2016
    Without comparative numbers, AKA amps drawn, it's difficult to diagnose any problem. A couple of things noted: The .8V difference between the SOC of the batteries and the charge controller should only occur with fully charged batteries. Float voltage from a solar charge controller is typically at 13.5V or higher. If you think your wiring may be insufficient, it probably is. Install larger wire. A 14.5 A charge current for the duration of a day should completely charge 225 AH of capacity, especially as an auxiliary to generator use. An inspection of the 120V converter should be high on your list.

    Your 12V system is not performing as good as it could. We don't know what the total draw is but if the fridge heat strip is removed from the total, you should have plenty of 12V power. It is not atypical to see the battery voltage dip to 11.9V when using slides. They are a large draw. If you leave the TV connected while running them out, it will help.

    FWIW, I operate a 120V fridge, all charging of devices, and power 120V entertainment devices using 235W of panel and 300AH of capacity. You must have some item that is drawing considerable power to lose charge so that your batteries are dead by morning. If I had to list a WAG, it is the heat strip on the fridge.

    Good luck on narrowing down the issues. BTW, a hydrometer is the tool to use to measure full SOC of the batteries. After a few charge cycles, the batteries should be dipped to establish a baseline specific gravity. Future charge measuring would relate to that baseline.
  • beemerphile1's avatar
    beemerphile1
    Explorer
    Sep 12, 2016
    westend wrote:
    Without comparative numbers, AKA amps drawn....


    This.

    You need to be measuring amps and turn things off and on until you find the major drain.
  • mikakuja's avatar
    mikakuja
    Explorer
    Sep 12, 2016
    THanks for all of the responses. To answer some of the above listed questions.,
    The fridge is turned on propane only always, unless the trailer is on shore power. Learned that the hard way years ago...
    The fridge is a Domestic DM2652. Thanks
    for the info and pics. I will be installing a switch ASAP..
    I will also be picking up an ammeter to measure draws as I don't currently have one. It is difficult to trace down loads without one... Numbers are everything.
    I'll post results as soon as I have them.
    As for the inverter, I tried both off and on during the night with the same resultsize. Just to rule out anything that may have been running on inverter power.
    The solar is wired in through the fridge vent to the 12v side of the power center, not directly to the batteries as I would have liked.. With that said I would only expect a .2ish vdc difference between the change controller and batteries.
    I will also be checking SOC with a hydrometer.
  • westend's avatar
    westend
    Explorer
    Sep 12, 2016
    The solar is wired in through the fridge vent to the 12v side of the power center, not directly to the batteries as I would have liked.. With that said I would only expect a .2ish vdc difference between the change controller and batteries.

    I'd bet you are dropping .2V just from the connection points. This is one sticking point with me that I just don't understand about RV'ers that install solar charging. They are OK with spending hundreds on the gear but balk on using larger wire to connect everything. It seems to me that with small solar, you'd want to get every last bit of power from the panels to the batteries. Maybe it's just me.
  • mikakuja's avatar
    mikakuja
    Explorer
    Sep 12, 2016
    Managed to get a bit of work done on the trailer today.. I didn't however get any numbers on Amp draws though... Bought a Mastercraft multimeter capable of measuring up to 20A DC current but guess what, it didn't work. Have to take it back and exchange it.
    What I did get done.

    Managed to disconnect the condensation heat strip in the fridge. Didn't put in a switch, just unplugged it. Everything seems to be working normally so far.

    Soldered the connections at the battery as they were not crimped properly and with not much of a pull they came apart.

    Replaced the main 30A fuse at the batteries with a proper 30A weatherproof main fuse with 6 AWG. The factory had installed the main fuse but used 8 AWG to the fuse where it changed to 12 AWG and a small automotive 30A fuse then into a main box where the wires were poorly joined together with a twist marette and back to 8 AWG running into the trailer.
    I then reset my solar controller to factory presets and reprogrammed it to my current battery setup.

    At this time the batteries which I thought were fully charged are still charging and the difference between the batteries and the controller is .2 to .3 higher at the controller while charging. I will measure the difference tonight after the sun is off the panels.

    Just to clarify for the last post.... I am running 12 AWG PV wire from the panels to the 20A solar controller. This should be more than ample for the system I am running.
  • FLY_4_FUN's avatar
    FLY_4_FUN
    Explorer
    Sep 12, 2016
    good work chasing down the small stuff....it all adds up in an rv electrical system. Its a silly thing but ensure your power booster for your tv is turned off when not in use as its usually hidden behind the tv or in a cabinet. The multimeter or a kill-a-watt meter will show you some interesting things where usage is concerned. Also always set a schedule to "water" your batteries if they in fact are maintenance ones.

    Daryll

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