Hab Battery Drain

Discussion in 'Tech/Mech General' started by Tincataylor, Aug 11, 2015.

  1. Tincataylor

    Tincataylor Funster

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    The hab battery battery on our 2008 Auto Sleeper continues to drain even when it is sitting on our drive with everything off. I have tried removing the fuses sequentially to try and isolate the drain without success. Although the action I have taken treats the effect rather than the cause I have fitted a battery isolator switch to the hab battery for when the camper is not in use and this has worked a treat as the hab battery now holds it charge week in week out. We also intend to isolate the hab battery while we are travelling and we are not in the van to stop it draining while we are out walking etc. The downside of this is the fridge which will not operate with the hab battery isolated. Would wiring a feed from the vehicle battery into the fridge be a sensible solution as the load on the vehicle battery from the fridge would be minimal.

    The Tinca's
     
  2. Clickem

    Clickem Funster

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    We had a similar experience and found that the drain was the reversing camera, wired in to the hab battery and drained it even when stood on the drive, unless on EHU

    Kept removing fuses until I traced the drain
     
  3. Don Quixote

    Don Quixote Funster

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    The best thing to do as your MH is parked on your drive is to connect the EHU cable. This will "trickle" charge your MH Hab and Veh batteries ( providing your MH charger charges both ) whilst parked up. When our MH is not in use it is connected to EHU 247.
     
  4. WillH

    WillH Funster

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    I fitted an isolating switch for the rear view camera, the feed was behind the radio. The exact cause was the infra-red LED's round the camera. Once the switch was fitted my battery drain was reduced considerably. The control panel also causes a drain so switch that of as well when not using the van. These problems all ceased when I had a solar panel fitted by Dave Newell(y)
     
  5. hilldweller

    hilldweller Funster Life Member

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    You are stacking up trouble for yourselves. For a start the hab battery is on charge whilst you drive.

    Solve your problem, don't make more.
     
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  6. Tincataylor

    Tincataylor Funster

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    Wise words Mr Hilldweller, treat the cause not the effect. Trouble is the engineers who have looked at it up to now have been unable to trace where the drain is and have stated that the control system itself drains the battery while in use and that there is nothing wrong with it. This is true but the rate of discharge should be milliamps in the "off" condition and not enough to drain the battery in a week or less.
    While we are driving we naturally have the hab battery on line so that it is being charged. We only use the isolator when the van is out of use and for this it seems to be totally effective. However if anybody has a bright idea of how to fix the problem of battery drain whilst the van is not in use please feel free to post

    The Tinca's
     
  7. Dave and Ginny

    Dave and Ginny Funster

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    Probably not going to be of use to you in, but I know on our Hymer, even with the 12 volts turned off, the circuit to the Truma frost safety drain is continually live and creates a small discharge.
     
  8. SomeoneElse

    SomeoneElse Funster

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    The OP doesn't say how big the drain is or how long until the battery is drained so here is my story.

    On our first MH, an Elddis Autoquest, it had a small analogue control panel with a switch to select which battery to use with a mid off position. The switch didn't control the battery current directly but operated one of two relays. The relay would take a tiny current, I thought, but on measuring it I found it was 60milliamps, I'll translate that later.
    The MH also had a Whale autofill water system (an invention of the devil in my view). The Whale system had a solenoid valve just inside the hose connector, this was normally close valve and was controlled by a float switch in the tank. Therefore unless the tank was absolutely full the solenoid valve was taking a similar current as the relay.
    So in total the passive load was 120milliamps, or in real money one eighth of an amp. Therefore it used one AH (AmpHour) per 8 hours, 3AH per day or over 20AH per week. I found the supplied 85AH battery was flat in a couple of weeks. The battery probably wasn't in the best of health!
    I therefore made sure the battery selection switch was in the mid (off) position when the MH was not in use.

    Edit: Another verbose posting :rolleyes:
     
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  9. Lenny HB

    Lenny HB Funster

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    You don't say how much the drain is, before worrying about it measure the current, on modern system up to 200 ma is quite normal in standby mode, with an LCD display & system switched on up to 500ma.
    200ma = 34 A/H a week, 500ma = 84 A/H a week.
     
  10. hilldweller

    hilldweller Funster Life Member

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    They are not good enough. Easily said. This is a very time consuming problem and maybe not economically viable if you can't DIY.

    But the least they should have done is quantify the problem, you can since you have a switch all you need do is put an ammeter across the switch in the off position and read off the drain. You can pull fuses and even disconnect suspect devices. Our cab radio is hooked to the hab battery, I found this after fitting a NASA battery monitor, which is an eye opener, it's spots everything.
     
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  11. Don Quixote

    Don Quixote Funster

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    My Victron 600s tells me that the control panel takes about 0.025amps when doing nothing and when I press any button jump up to 0.089amps. The fridge draws 0.020 when just sitting there and when gas kicks in draws 0.070amps.
    I know boring stuff, but the things you find out with the Victron.
     
  12. TheCaller

    TheCaller Funster

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    Nothing wrong with that. Usual problem on here is that we only get half the story.
     
  13. Don Quixote

    Don Quixote Funster

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    Please ignore this "verbose" thing as many on this forum do not have the knowledge and any information that can help others no matter how detailed is gratefully received. Thats why MHF works.
     
  14. SomeoneElse

    SomeoneElse Funster

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    It not rocket science, the load is going to be small so an heavy duty ammeter isn't needed.
    Just put some spade connectors on the meter probe wires and run down the fuse panel using the meter instead of each fuse. You'll soon know which circuit(s) is(are) causing the drain.
     
  15. hilldweller

    hilldweller Funster Life Member

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    Good advice but assumes there are no hidden circuits connected to the battery.

    No-one has suggested the battery might be past it's best. It might hold it's volts but that's nothing to do with capacity.
     
  16. Don Quixote

    Don Quixote Funster

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    The problem is many MH owners do not own a ammeter/voltmeter/digital multimeter
    or for that matter, may own one and not have a clue how it works and how it's the main tool you need in a MH.
     
  17. tonyidle

    tonyidle Funster

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    500mA (1/2A) will discharge (to the point of damage) a 100Ah in a week. It doesn't take much current draw! Less than half of that will fully discharge it (as far as a meter measurement is concerned and without damage) in a week.
     
  18. SomeoneElse

    SomeoneElse Funster

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    Thats very true DQ, but the OP commented that "engineers" could find the drain. I assume they were talking about auto-electricians who should have a multimeter and know how to use it.
     
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  19. vin0114

    vin0114 Funster

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    Like willH suggested, presuming you have room on your roof, fit a solar panel.
     
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