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Shades And Battery

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#1 Butche60



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Posted 05 November 2013 - 12:43 PM

I own a Winnago with electric solar and night shades at the windshield.


My problem is the manual says not to let the voltage drop below 11 volts or you can lose the set points for the shades. I monitored the voltage on our trip and I didn't let it drop. I still lost the set points.


I contacted the manufacturer and he said not to let the voltage drop 12. He also said I might have a problem with the battery. I checked and when the engine is running it is charging at 14.2-14.4. When the engine is turned off it drops to 12.1 - 12.3 right away. Is this normal or do I have a battery going bad ?

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#2 DickandLois


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Posted 05 November 2013 - 01:21 PM

Hi Butch,


Welcome to FMCA!


The fact that the voltage drops 2 volts as soon as you turn off the engine would point to a coach / house battery problem.

One would expect to see the batteries read from 13.5 volts when the engine is off to a low of 12.5 volts.

After the coach sets for 30mi. to an Hr. what do the batteries read? If they drop another volt or 2 sounds like you have a bad one in the set.


Have you been checking the water levels of all the cells on a regular bases?

The best way to check the battery is with a hydrometer. Checking all the cells if they are wet cells.

Glass mate / dry cells need to checked with a volt meter.


Good test for both types is a load test done at a service center or battery supplier,  most owners do not own the load testing equipment.



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#3 wolfe10


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Posted 05 November 2013 - 02:06 PM

Yes, sounds like battery problem.


First, let's identify which battery bank you are talking about.


Please verify that the shades operate on the HOUSE battery bank, not CHASSIS battery bank.


If house, that bank should charge from either engine (alternator) or from shore power/generator via your charger or inverter/charger.


If chassis, it should charge from engine and MAY, repeat MAY also charge from your charger or inverter/charger (not all are wired to charge from shore power/generator


OK from either alternator or charger or inverter charger, voltage at the batteries should be 13- 14.5 VDC.


As soon as charging source is removed, the batteries quickly dissipate their "surface charge" and drop to voltage of a 100% charged 12 VDC battery-- 12.7 VDC.


From there the voltage should drop very slowly (depending on amp draw and size of battery bank (in amp-hrs).  50% discharged is 12.2 VDC.


As an example, if your batteries are in good condition and fully charged and you have 4 6VDC golf cart batteries for your house bank (and the shades run on the house battery as I suspect they do) you have 440 amp-hrs @ 12 VDC.  So, if you run a 10 amp load, it would take 22 hours to discharge your battery bank to 50%.


If the voltage drop is as quick (below 12.7 VDC) you very likely have one or more bad batteries.  And if over a year or so old, replace all batteries that make up that bank.



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