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Battery electrics don't work.


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Hi all, quite new to this!

My caravan electrics work fine while hooked up,also when connected to car, however nothing works with just leasure battery connected,   except motor mover.

Is this normal, "I don't think so". Thanks.

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Quite likely a blown main fuse. Often hidden away under or near the battery box in the red wire.

  • I agree completely 1
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The mover is connected directly to the battery so if that is not working as well not only is the 'embedded' fuse blown but the battery is flat as well since the power supply/charger is the other side of the blown fuse. The mover control unit drain if switched on is a matter of milliamps - literally the current drawn by the power indication LED (and that from the mouth of Powrtouch!)

 

I would strongly suggest that before you replace the fuse you should disconnect the battery negative so that if the battery has got a duff cell or has damaged plates the inrush of current does not blow your power supply as well when you reconnect the mains.

 

If you have a voltmeter check the battery voltage before you replace any blown fuse. If it reads below 10.8V you are very unlikely to be able to recover it even with a very clever smart charger. If it is above 10.8V you could try connecting a car headlamp bulb in series between the negative cable and the battery negative terminal which will limit the inrush current to something less than 5A. If the battery voltage is say 11.5V or higher then you could use a 21W flasher bulb. Either bulb will light brightly when the mains is first powered up and will gradually dim and eventually go out as the battery plate voltage rises. When the bulb goes out switch off the mains, remove the bulb, and reconnect the negative cable to the battery, then switch the mains on again. The battery will come up eventually over a day or so. However a good test would be to remove the mains after 24hrs, read the battery voltage, leave it 48hrs and read the voltage again without reconnecting the mains. If it has dropped by more than about ¼V the battery may need replacement.

 

Oh and before anyone says you should remove the positive cable from the battery not the negative, it is always good practice in a caravan (and a car for that matter) to disconnect the negative which is connected to the chassis and possibly other metals leaving the open possibility of a short circuit occurring: remove the negative and that cannot happen.

 

Simples?

2018 Passat B8 Estate 150GT TDi150 towing a 2018 Bailey Unicorn S4 Seville

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31 minutes ago, Woodentop said:

The mover is connected directly to the battery so if that is not working as well not only is the 'embedded' fuse blown but the battery is flat as well since the power supply/charger is the other side of the blown fuse. The mover control unit drain if switched on is a matter of milliamps - literally the current drawn by the power indication LED (and that from the mouth of Powrtouch!)

 

I would strongly suggest that before you replace the fuse you should disconnect the battery negative so that if the battery has got a duff cell or has damaged plates the inrush of current does not blow your power supply as well when you reconnect the mains.

 

If you have a voltmeter check the battery voltage before you replace any blown fuse. If it reads below 10.8V you are very unlikely to be able to recover it even with a very clever smart charger. If it is above 10.8V you could try connecting a car headlamp bulb in series between the negative cable and the battery negative terminal which will limit the inrush current to something less than 5A. If the battery voltage is say 11.5V or higher then you could use a 21W flasher bulb. Either bulb will light brightly when the mains is first powered up and will gradually dim and eventually go out as the battery plate voltage rises. When the bulb goes out switch off the mains, remove the bulb, and reconnect the negative cable to the battery, then switch the mains on again. The battery will come up eventually over a day or so. However a good test would be to remove the mains after 24hrs, read the battery voltage, leave it 48hrs and read the voltage again without reconnecting the mains. If it has dropped by more than about ¼V the battery may need replacement.

 

Oh and before anyone says you should remove the positive cable from the battery not the negative, it is always good practice in a caravan (and a car for that matter) to disconnect the negative which is connected to the chassis and possibly other metals leaving the open possibility of a short circuit occurring: remove the negative and that cannot happen.

 

Simples?

Would hope the caravan battery isn't connected to the chassis! 

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35 minutes ago, Woodentop said:

The mover is connected directly to the battery so if that is not working as well not only is the 'embedded' fuse blown but the battery is flat as well since the power supply/charger is the other side of the blown fuse. The mover control unit drain if switched on is a matter of milliamps - literally the current drawn by the power indication LED (and that from the mouth of Powrtouch!)

 

The OP seemed to be saying that the mover was the only thing that DID work!

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26 minutes ago, joanie said:

have you switched on the main  black switch?

+1...maybe 12 volt isolator hasnt been switched on.

 

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On 18/09/2020 at 16:14, Dobloseven said:

Would hope the caravan battery isn't connected to the chassis! 

 

Why not? That’s what all cars have! 

Experience is an awful teacher who ends up sending you simply horrifying bills

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13 minutes ago, Mr Plodd said:

 

Why not? That’s what all cars have! 

I suppose the big difference with a caravan is it is not all metal like a car so any wires for the negative would still need to go to the chassis and not a bit of metal next to the lights or whatever. Taking the negative wire back to the fuse box/battery area (along with the positive) is probably not much different to the chassis.

  • I do not understand 1
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