Bailey senator vermount Battery

[Gralay]

In plain English and my English is poor you need the battery to complete the circuit so that you can have 12v. Even though you are connected to 240v a flat battery will make it appear as if the lights are very dim. remove the battery and the 12v will shut down. That is my personal experience on a Bailey Pageant circa about 2006/7.

We have a Bailey Senator Oklahoma series 5 2006 I have just tried disconnecting the battery and putting on ehu, all 12v systems work as they should including on board pump

Gra

 

[ProfJohnL]

We have a Bailey Senator Oklahoma series 5 2006 I have just tried disconnecting the battery and putting on ehu, all 12v systems work as they should including on board pump

Gra

That is what I would expect, as most caravan mains to 12V converters are now true power supplies, and provided you do not exceed their output current capacity you can in theory run a caravan without a 12V battery. However there are more and more 12V devices being fitted to caravans, and if all of them were turned on at the same time its very likely teh PSU would not be able to meet the maximum demand, which is why having s 12V battery is a good idea to act as extra peak demand supply capacity.

 

[Gralay]

That is what I would expect, as most caravan mains to 12V converters are now true power supplies, and provided you do not exceed their output current capacity you can in theory run a caravan without a 12V battery. However there are more and more 12V devices being fitted to caravans, and if all of them were turned on at the same time its very likely teh PSU would not be able to meet the maximum demand, which is why having s 12V battery is a good idea to act as extra peak demand supply capacity.

I only posted my reply to verify that a series 5 Senator could run 12v systems with the battery disconnected as Buckman and Woodentop had conflicting views

Gra

 

[ProfJohnL]

I only posted my reply to verify that a series 5 Senator could run 12v systems with the battery disconnected as Buckman and Woodentop had conflicting views

Gra

Thats fine, I was agreeing with you. An SMPS or Switched Mode Power Supply is a true PSU or Power Supply Unit. They produce a smoothed DC output voltage which teh caravan cannot distinguish from a battery, except they do have a limited output current output. Technically provided the load on the 12V system does not exceed the PSU's capability the caravan won't know the difference between the PSU and a battery, so you can run most of the caravan without a battery in circuit.

Older caravans didn't have PSU's they only had battery chargers, and these are differnt to a true PSU. Traditional battery chargers do not produce pure DC at a constant voltage, they actually produced either a half wave rectified Sine wave or a full wave rectified sine wave (depending on the design of the circuit). The crucial difference is the unloaded rectified output actually goes from 0V to a peak value of around 21Vdc (or more) like a switch being turned on and off 50 (Half Wave) or 100 (Full Wave) times a second. The output also has a modest impedance which means when its loaded the peak output voltage does not go quite as high. But its the gaps between the peaks that are the problem, and that's where using a battery helps.

When the output voltage goes above the voltage of the battery, the battery absorbs the peak voltage and uses it to charge the battery, but when the output fall below the batteries terminal voltage, the battery supplies current to the load until the chargers output rises again on the next cycle.

The problem with these older type charger circuits is they could not tell when teh battery was fully charged, and would continue to over charge them if the caravan was in storage.

The new PSU type units are voltage capped to prevent over charging. And some of the very latest units do have some "smart" capability and will monitor the battery status and only provide charge current when needed.