Average 11.5 v all weekend (1 Viewer)

Jun 11, 2011
306
982
Derby
Funster No
16,833
MH
Autotrail Cheyenne 840 SE
Exp
2006
Hi all, could I have a bit of help please?
First time without Lecky last weekend, 3 days at the Newbury show. We are not big uses of electric just the usual pumps, lights, couple of hours tv and that's about it. On the second day we needed a bit of heat so popped the Truma on when the fan tried to kick in the lights would dim and the fan hunted on and off.
Voltage dropped to about 11v. when there is nothing on we still seem to be using 3amp's is this usual?
The M'home has been standing since Sunday and just checked voltage and it's showing 11.7v so doesn't seem to lose any power.
The leisure battery is a Numax 110 amp and approx' 1 year old.

I am thinking about fitting two new batteries as above and two 120 watt solar panels.

Now the Sargent box in the M'home supports solar up-to 120w what would be the best configuration to accommodate both panels?

Thanks in anticipation of your help

Cheers
Colin
 
Oct 16, 2018
640
1,650
CHESTERFIELD DERBYSHIRE
Funster No
56,769
MH
PILOTE
Exp
Long enough
12.2 v is only 25% charge level - below that your battery is not very good at all.
It should be 12.7v or more when fully charged.
Solar panels will solve most of your problems most of the year but your present battery looks as if its knackered.
Note - I am not a qualified electrician.
 
Apr 27, 2016
6,872
7,992
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
First, I wouldn't completely trust the display panel until you've double-checked it with a multimeter. What is the voltage reading at the actual battery terminals using a multimeter?

Having said that, the symptoms are what you'd expect of a low battery. The 3 amps when nothing is supposed to be on is not usual, maybe other Autotrail owners can say what the expected value is. 3 amps will more or less flatten your battery in 24 hours. If it's a real value, not just a faulty meter, then it needs to be fixed.

For comparison, 3 amps for 24 hours is 72 amp-hours. You'll be lucky to get 100 amp-hours per day out of two 120 watt solar panels, so that won't really solve your problem

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NickandClair

Free Member
Apr 30, 2018
86
95
Taunton, Somerset
Funster No
53,652
MH
The Dark Side!!!!
Exp
Since 2001
Some factory gauges can be as much as .5v +/-, so it has been suggested previously to measure using a voltmeter at the battery. Also if the solar has been wired through a factory consumer unit, you can also loose efficiency that way, but never would I have thought it would be that much.
All these things aside, 11.7V is low for the charged state of a battery and certainly needs more investigation, as at that sort of voltage, you would be at roughly 25-30% capacity and repeated, would certainly reduce a typical lead acid leisure battery's life.
My advise is to have it either checked out (both battery and solar output), or using a multi-meter and check the voltage at the battery and check the output of your regulator.
Hope you get to the bottom of the issue (y).
 

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