Main battery fuse

Sep 15, 2022
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Hi all , hope someone can help. I run a 2011 Baily Unicien Valencia. When I turn off mains power I lose power to van even though the battery is charged fully. I have check the panel battery fuse and this is fine. Thanks in advance Jim.
 
Jun 16, 2020
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When mains is on, do the 12 volt lights and sockets work?

Check the in-line 20 amp fuse located just behind the battery box.

John
 
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Mar 14, 2005
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Hello Jim,

I see you are new to the forum. Welcome.

Are you also new to caravanning? Because if you are you may not fully understand how the electrics in a caravan work.

You have a 230Vac mains system which is only available when you connect the caravan to a mains supply using the Electrical Hook Up (EHU) cable. If you aren't connected to the mains , none of the mains only powered appliances will work.

One of the mains powered appliances will be a 12V power supply which also charges the battery, so when mains is supplied to the caravan both mains and 12V appliances will work. But if the mains is disconnected then only the 12V systems will work.

Does this help?
 
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Sep 15, 2022
19
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Hello Jim,

I see you are new to the forum. Welcome.

Are you also new to caravanning? Because if you are you may not fully understand how the electrics in a caravan work.

You have a 230Vac mains system which is only available when you connect the caravan to a mains supply using the Electrical Hook Up (EHU) cable. If you aren't connected to the mains , none of the mains only powered appliances will work.

One of the mains powered appliances will be a 12V power supply which also charges the battery, so when mains is supplied to the caravan both mains and 12V appliances will work. But if the mains is disconnected then only the 12V systems will work.

Does this help?
Hello Jim,

I see you are new to the forum. Welcome.

Are you also new to caravanning? Because if you are you may not fully understand how the electrics in a caravan work.

You have a 230Vac mains system which is only available when you connect the caravan to a mains supply using the Electrical Hook Up (EHU) cable. If you aren't connected to the mains , none of the mains only powered appliances will work.

One of the mains powered appliances will be a 12V power supply which also charges the battery, so when mains is supplied to the caravan both mains and 12V appliances will work. But if the mains is disconnected then only the 12V systems will work.

Does this help?
Hi John, thanks for the reply a d not that new at caravanning. Basically I have checked out a electrics even battery fuse in main box. I know I should have 12 v or there abouts when running off battery which I have at the battery. However it doesn't amp up to 12 on the van and I can't use the motor mover. Hence the reason for me trying to find the 20 v mains battery. I posted a picture of where I think it is and I was hoping for confirmation before I clambered under the bed.
Jim
 
Jun 16, 2020
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Hence the reason for me trying to find the 20 v mains battery. I posted a picture of where I think it is and I was hoping for confirmation before I clambered under the bed.
Jim
Find the red wire that comes from the battery. NOT the one from the mains. Follow this, and within a couple of foot you should find an in-line fuse holder.

1664553896024.png

Check the fuse. Should be 20 amp, (not 20v).

I don't hold out much hope that that is what is the problem. As that fuse has nothing to do with the mover. The mover is on it's own circuit from the battery and is independent from the rest of the electrics.

John
 
Mar 14, 2005
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I presume you meant your looking for a 20A fuse. from the battery, Unfortunately the picture you have posted does not show enough of the wiring to confirm which wire it may be in, But if you have a caravan mover, it will have its own wires specially for the mover, and they will be much bigger than most of the other wires in the caravan.

A fully charged battery should between 12.8V and 13.2V (without the charger turned on) you tell us its only about 12V which suggests the battery is not full charged.

I suggest you get the battery checked at a battery depot. It might be worn out and unable to power your mover.
 
Sep 15, 2022
19
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Find the red wire that comes from the battery. NOT the one from the mains. Follow this, and within a couple of foot you should find an in-line fuse holder.

View attachment 3949

Check the fuse. Should be 20 amp, (not 20v).

I don't hold out much hope that that is what is the problem. As that fuse has nothing to do with the mover. The mover is on it's own circuit from the battery and is independent from the rest of the electrics.

John
Hi John thanks for that, I will get a look for that . I'm stumped, I have a full battery but I get nothing on the main amp meter in the van. arrrh
 
Sep 15, 2022
19
1
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I presume you meant your looking for a 20A fuse. from the battery, Unfortunately the picture you have posted does not show enough of the wiring to confirm which wire it may be in, But if you have a caravan mover, it will have its own wires specially for the mover, and they will be much bigger than most of the other wires in the caravan.

A fully charged battery should between 12.8V and 13.2V (without the charger turned on) you tell us its only about 12V which suggests the battery is not full charged.

I suggest you get the battery checked at a battery depot. It might be worn out and unable to power your mover.
Hi John thanks but at 12amp it should show on the amp meter should it not?
 
Nov 16, 2015
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Hi John thanks but at 12amp it should show on the amp meter should it not?
Jim, I am thinking you mean the Volt meter in the caravan, not an Amp meter. The voltmeter in my van is no super accurate, but within 1/2 a volt.
Not to confuse you the motor mover will have a separate fuse possibly 80 amp. Which makes me think the charging side of your power unit has broken down, therefore not charging your battery. And therefore not supplying a charge to the battery?
If you connect a voltmeter to the battery you should see about 13.5 volts if the charger is working when connected to EHU.
I hope this helps.

Jim as an edit, in your picture of the rat's nest of wires, the oblong black box in the orange cable, with the tyewrap will be the motor mover fuse.
 
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Sep 15, 2022
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Jim, I am thinking you mean the Volt meter in the caravan, not an Amp meter. The voltmeter in my van is no super accurate, but within 1/2 a volt.
Not to confuse you the motor mover will have a separate fuse possibly 80 amp. Which makes me think the charging side of your power unit has broken down, therefore not charging your battery. And therefore not supplying a charge to the battery?
If you connect a voltmeter to the battery you should see about 13.5 volts if the charger is working when connected to EHU.
I hope this helps.

Jim as an edit, in your picture of the rat's nest of wires, the oblong black box in the orange cable, with the tyewrap will be the motor mover fuse.
Hi Hutch, and everyone I will check out suggestions by Hutch once the rain stops long enough down our way and give the feedback. Much appreciated everyone's input. Jim
 
Nov 16, 2015
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Ii hate it when you get what coud be a simple. Fix , but it. Is not.
Good luck keep us informed
 
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Sep 15, 2022
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Ii hate it when you get what coud be a simple. Fix , but it. Is not.
Good luck keep us informed
Hi Hutch I have connected to mains and just checked the battery while connected and only showing 7.5. I'm now charging the battery anyway.
 
Sep 15, 2022
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Hi Hutch I have connected to mains and just checked the battery while connected and only showing 7.5. I'm now charging the battery anyway.
So when I fully charge my battery and disconnect from EHU I should see 13V when I switch on master
 
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Hi Jim
If the 12v lights are working OK the battery fuse is OK, so the problem is on the power supply, as you have checked the ps fuse and that is OK the only other things it could be are the plugs connecting the power supply to mains or the power supply itself. When checking the ps plugs ensure the ehu is disconnected.

Gra
 
Sep 15, 2022
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Hi Jim
If the 12v lights are working OK the battery fuse is OK, so the problem is on the power supply, as you have checked the ps fuse and that is OK the only other things it could be are the plugs connecting the power supply to mains or the power supply itself. When checking the ps plugs ensure the ehu is disconnected.

Gra
Hi people, so the van lights ,fridge heating all works when on EHU. The caravan or motor mover won't work on leisure battery. So the consensus is that it must be the power supply unit. Do we agree. If so, anyone know where the best place for baily unicorn spares and parts?
 
Nov 11, 2009
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Hi people, so the van lights ,fridge heating all works when on EHU. The caravan or motor mover won't work on leisure battery. So the consensus is that it must be the power supply unit. Do we agree. If so, anyone know where the best place for baily unicorn spares and parts?
You can buy them from many caravan accessory outlets but there’s a company that make an improved version on a 1:4:1 swop being interchangeable. Apuljack.


See this thread

 
Jun 16, 2020
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Hi people, so the van lights ,fridge heating all works when on EHU. The caravan or motor mover won't work on leisure battery. So the consensus is that it must be the power supply unit. Do we agree. If so, anyone know where the best place for baily unicorn spares and parts?
First double check the power supply. It’s easy,

unplug the hook up. and test the battery voltage.
plug the hook up back in, make sure the power supply (charger), is turned on if there is an isolator or fuse or switch.
check the battery again,
if the voltage has jumped up to 13 plus, the power supply is OK.

The new power supply has two jobs,
1 powering all 12 volt items,
2 keeping the battery topped up.

They are normally 20 amp. The better ones have smart charging abilities which are better for the battery. Most are interchangeable, so you do not have to get the same and pay spare part prices.

A quick Google seems to show they are about £135. with the Apuljack £165. Mine failed in my Unicorn about 9 years ago. I got a good one for £85, inflation eh!

John
 
Sep 15, 2022
19
1
15
First double check the power supply. It’s easy,

unplug the hook up. and test the battery voltage.
plug the hook up back in, make sure the power supply (charger), is turned on if there is an isolator or fuse or switch.
check the battery again,
if the voltage has jumped up to 13 plus, the power supply is OK.

The new power supply has two jobs,
1 powering all 12 volt items,
2 keeping the battery topped up.

They are normally 20 amp. The better ones have smart charging abilities which are better for the battery. Most are interchangeable, so you do not have to get the same and pay spare part prices.

A quick Google seems to show they are about £135. with the Apuljack £165. Mine failed in my Unicorn about 9 years ago. I got a good one for £85, inflation eh!

John
Hi John will give it a go tomorrow. I have been charging battery from this and it is at 12 at the moment

Jim
 
Sep 15, 2022
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I battery charged it over night and only got up to 12 5 so that means it's done. However I reconnected and plugged I to mains and I got the same 12.5. So am I right in thinking the charger part in EHU has broken and if so is it just a case of unscrewing the cover and replacing it? Thanks Jim
 

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Jun 16, 2020
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A freshly charged, good battery, should be more like 13.5v, so your battery is suspect. when you have given it a good charge, remove it from the charger and check the voltage every so often over a period of time. You should find there may be an initial slight drop, but after that voltage should be maintained for weeks. if it drops over a short time. The battery has had it.

When it goes back on the van, there should be an obvious increase when the van is powered up. This shows the van's power supply is working.

John
 
Jun 16, 2020
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I battery charged it over night and only got up to 12 5 so that means it's done. However I reconnected and plugged I to mains and I got the same 12.5. So am I right in thinking the charger part in EHU has broken and if so is it just a case of unscrewing the cover and replacing it? Thanks Jim
Is your caravan's power supply built into the consumer unit? If so, you can change like for like. or, do what I did, install a better unit next to the consumer unit and wire it through the back. but please get someone competent to do that.

John
 
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