# Fitted 12v socket BUT!!!



## namder (Sep 20, 2006)

Just fitted 12v socket direct to leisure batteries on my Autotrail Apache 725. I have one of those little gizmos that you can plug into the socket that gives a voltage readout. Without the EHU connected, the gizmo was reading 12.5V. When I connected the EHU and turned on the charger, the voltage stayed at 12.5v. I would have expected this to rise slightly. To further test I turned the TV on and ran that for about 3 hrs with the charger turned off and EHU disconnected. The control panel showed a marked decrease in voltage but the gizmo still showed 12.5 volts.

My 2x110 batteries are conected via built in wiring looms and I connected the socket to one of them. Is this correct? The charger is working fine and I did have the 12v selector set to leisure battery. I have a battery master fitted. The gizmo seems to be fine 'cos plugged into the dash socket it reads 12.5v+/- until I start the engine when it rises to 14v+ 

I am puzzled, any suggestions?

John


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## Mark993 (Jul 1, 2007)

You have probably already checked this, but is it possible there is a wiring fault between your two leisure batteries? I mean such that one of them is being charged and supplying power to the 12v system and the other is not. Plus you just happen, in making your direct connection with the new socket, to have connected it to the battery that's not charging/supplying.

Just an idea.


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## namder (Sep 20, 2006)

The battery wiring is pre-installed by manufacturer so wouldn't suspect this but how could I check?

John


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## HarleyDave (Jul 1, 2007)

Leave the gizmo plugged into (what you believe to be) the leisure battery circuit and start the engine - if the voltage rises you are connected to the vehicle battery

It's quite a coincidence that both leisure and vehicle batteries are at 12.5v

Cheers

Dave


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## Mark993 (Jul 1, 2007)

namder said:


> The battery wiring is pre-installed by manufacturer so wouldn't suspect this but how could I check?
> 
> John


Maybe a connection has come loose. I'd just have a look at the wiring and follow the cables, check they are connected properly. Although you mentioned a loom so perhaps they are hidden/tough to follow in which case you would need to disconnect them all from all the batteries and uses a multimeter to check which ends match with this other ends.

But Dave makes a very good suggestion.


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## joedenise (Jul 20, 2007)

what does a multimeter say your leisure batteries voltage is

joe


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## namder (Sep 20, 2006)

HarleyDave said:


> Leave the gizmo plugged into (what you believe to be) the leisure battery circuit and start the engine - if the voltage rises you are connected to the vehicle battery
> 
> It's quite a coincidence that both leisure and vehicle batteries are at 12.5v
> 
> ...


I connected the socket to the leisure batteries myself. They are in a different location to the vehicle battery.

Isn't it possible that the vehicle and leisure batteries are at the same voltage because they are connected to each other by the battery management system (csb2)?

John


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## MYFANWY1 (May 9, 2011)

*12volt*

Hi John, done the same thing myself on my Mohawk 2011, if you put the second battery on yourself you must let the control panel know,
Silly I now, engineer must do it there is a code they use, they did mine no charge, hope this helps.
Eddie.


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## rayc (Jun 3, 2008)

namder said:


> HarleyDave said:
> 
> 
> > Leave the gizmo plugged into (what you believe to be) the leisure battery circuit and start the engine - if the voltage rises you are connected to the vehicle battery
> ...


The cab and habitation batteries will be paralleled but only when the engine is running. When the engine is not running they are isolated from each other.

The question has to be are BOTH the habitation batteries being charged by the EHU charger and if so why is your new socket not measuring the charger voltage? What are the habitation battery terminal voltages with charger on and off?


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## namder (Sep 20, 2006)

*Re: 12volt*



MYFANWY1 said:


> Hi John, done the same thing myself on my Mohawk 2011, if you put the second battery on yourself you must let the control panel know,
> Silly I now, engineer must do it there is a code they use, they did mine no charge, hope this helps.
> Eddie.


Thanks Eddie. Now!!! I don't have contacts with an engineer capable of doing this, does anyone on this forum know how to reset the control panel?

John


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## rayc (Jun 3, 2008)

*Re: 12volt*



MYFANWY1 said:


> Hi John, done the same thing myself on my Mohawk 2011, if you put the second battery on yourself you must let the control panel know,
> Silly I now, engineer must do it there is a code they use, they did mine no charge, hope this helps.
> Eddie.


That implies that the OP has been running on one battery only and the other has not been connected via the wiring harness and control circuitry. Lucky he has got any voltage on it if it was installed some time ago.

The harness to the second battery should have its own fuse. I wonder if it was fitted when the battery was installed?


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## namder (Sep 20, 2006)

rayc said:


> namder said:
> 
> 
> > HarleyDave said:
> ...


Thank you RayC

Under charge from the onboard charger or solar panel, I believe that the batteries are connected together whenever the leisure batteries reach a certain level, because the leisure batteries pass a charge to the vehicle battery via the CSB2.

If the weather permits tomorrow, I will check the leisure battery voltages both on and off charge.

John


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## namder (Sep 20, 2006)

*Re: 12volt*



rayc said:


> MYFANWY1 said:
> 
> 
> > Hi John, done the same thing myself on my Mohawk 2011, if you put the second battery on yourself you must let the control panel know,
> ...


The harness for the second battery has a 20amp fuse fitted although I will check tomorrow if it's blown.

When I enquired about fitting the battery master, I was advised by Sargents that they couldn't advise it because it could interfere with the charging circuit. This idea was debunked on here as they are widely used without apparent problems! It makes me think though.

John


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## rayc (Jun 3, 2008)

namder said:


> rayc said:
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> > namder said:
> ...


That is not quite correct. It is still the charger or solar panel that passes voltage to the cab battery and not the leisure battery. The cab and leisure batteries are still electrically separated by the control system unlike when they are being charged by the alternator when they are in effect paralleled.

When I read the voltages of my leisure batteries and cab battery when being charged by the charger or solar panel they do not show exactly the same voltage. That clearly shows they are not connected directly together. When the engine is running I get an icon showing that the batteries are connected together and the voltages are exactly the same/


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## rayc (Jun 3, 2008)

*Re: 12volt*



namder said:


> rayc said:
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> > MYFANWY1 said:
> ...


Fitting a battery master to a CBE system as used in the Rapido definitely causes problems. In any event why would you need one? It appears you can charge the leisure and cab batteries from EHU and solar and also both from the alternator? It appears you only have one problem and that is to do with the second leisure battery, which I assume is the one that your new socket is attached to..

What model of Sargent controller do you have? It would appear that the setting on the control panel is the way forward as Eddie previously said. I cannot see why it need two circuits as simply linking the two batteries in parallel with battery links would suffice. I am sure that Sargent's know better of course.


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## namder (Sep 20, 2006)

*Re: 12volt*



rayc said:


> namder said:
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> > rayc said:
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My Sargent controller is the EC225 and this model doesn't allow the solar to charge both van and leisure, only the one that it's physically connected to.
The new socket is connected to the original leisure battery.

John


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## rayc (Jun 3, 2008)

*Re: 12volt*



namder said:


> rayc said:
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> > namder said:
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Sounds like an inefficient system to me. Anyway now we have established that your new socket is attached to the original battery then its apparent its got nothing to do with the control panel set up. It's back to checking the battery terminal volts with the charger on and off and confirming the socket voltages are the same.


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## Raptor107 (Oct 25, 2011)

*Apache charging 2nd leisure battery*

Hi John,
At present I am on a campsite and also have an Apache 700se, I also added a second leisure battery using the extra harness from sargents . I have just gone and checked the batteries voltage at the terminals both say 13.48v at each terminus with the Sargent psu225 switched to charge. I also use solar panels but these are connected direct to the battery poles as the 225 doesn't have a solar input and i hadn't used hook up until this week so thought I could have the same problem!
I just saw on the Sargent website that the 225psu will not start charging until the voltage is below 12.5 (see user manual PDF on their website) and a comment states that often people think they have a supply charging issue. 
Dave


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## namder (Sep 20, 2006)

Thanks to all who responded. I'm ashamed to admit that it was nothing more than the fuse on the battery had blown. All OK now. At least I understand a little more about batteries and charging now.

John


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