On board 12v power supply

[adam1111]

Hi all I have a bailey ruby 98year caravan

The on board 12v power supply that should be reading 13.8v on a multimeter.

With power to it is only reading 10.80v
With no power to it it's reading 8.44.

Also making a noise it will get to 10.80v then drop and climb to 10.80v again.

Could any1 advise me how to fix so I can get it to 13.8 plz thank you

 

[ProfJohnL]

Its obviously difficult to accurately diagnose faults using a forum, but based on what you have told us so far, it does look as though the onboard charger may be working, as the "12"v lime increases when the 230V mains is applied. The unknown problem is why is it only reachiching 10.8V rather than 13.8, and that I suspect might point to a faulty battery. possibly 1 or more cells gone short circuit. At 10.8V the battery is considered to be fully discharged.

To try and check to see what might be causing I suggest that you carefully turn off all the 12V appliances and lights and carefully disconnect the negative terminal of the battery. If you have a multimeter check to see what the voltage across the battery cables is (not across the battery) If the voltage rises to 13.8 when the charger is turned on. that shows the charger is ok and the battery must be suspect.

If the voltage does not rise then it could well be a faulty on board charger. Look up Apuljack who understand a lot about caravan power supplies. and might manufacture a replacement for yours.

Temporarily you could use an ordinary battery charger or better a smart charger connected directly to the battery which should recharge and support the caravan.

 

[Buckman]

Disconnect the battery and measure across the terminals. If low, put the battery on charge. After charging let it stand at least for a day before checking terminals for voltage again. This should be a good indicator if the battery is on its way out.

 

[adam1111]

Its obviously difficult to accurately diagnose faults using a forum, but based on what you have told us so far, it does look as though the onboard charger may be working, as the "12"v lime increases when the 230V mains is applied. The unknown problem is why is it only reachiching 10.8V rather than 13.8, and that I suspect might point to a faulty battery. possibly 1 or more cells gone short circuit. At 10.8V the battery is considered to be fully discharged.

To try and check to see what might be causing I suggest that you carefully turn off all the 12V appliances and lights and carefully disconnect the negative terminal of the battery. If you have a multimeter check to see what the voltage across the battery cables is (not across the battery) If the voltage rises to 13.8 when the charger is turned on. that shows the charger is ok and the battery must be suspect.

If the voltage does not rise then it could well be a faulty on board charger. Look up Apuljack who understand a lot about caravan power supplies. and might manufacture a replacement for yours.

Temporarily you could use an ordinary battery charger or better a smart charger connected directly to the battery which should recharge and support the caravan.

Did that still no change

 

[adam1111]

Disconnect the battery and measure across the terminals. If low, put the battery on charge. After charging let it stand at least for a day before checking terminals for voltage again. This should be a good indicator if the battery is on its way out.

Charged a few times from fully charged my water pump will be working for say 20 minutes therefore I really think it's the charger at fault

 

[ProfJohnL]

Did that still no change

Did what exactly, I gave you several different options. But based on your answer to buckman, it does look more likely to be the charger.

Find the chargers make and model number and contact Apuljack

 

[adam1111]

Did what exactly, I gave you several different options. But based on your answer to buckman, it does look more likely to be the charger.

Find the chargers make and model number and contact Apuljack

I checked the v on the wires still no change but have found one of the wire connectors wasn't solderd to the board so im pretty sure this is what the fault is but thank u for ur help