Leisure Batteries

[missdiamonique]

We have just purchased a new leisure battery for use over the winter to power the caravan's alarm. As we are not technically minded, how do we charge the leisure battery and when? Do we take the battery home and charge it with a proper leisure battery charger or can we plug the charger into one of the sockets in the van and charge the battery whilst in its place in the side of the van? Why does the charger in the bedbox not charge it when it is switched on? Is this only for when we are towing? Any suggestions please?

 

[RogerL]

Most modern caravans have a power supply (often wrongly called a charger) which supplies 12v nominal to internal equipment while the caravan is hooked up to mains electricity. This power supply will also charge the leisure battery but only to about 80% capacity. A power supply runs at 13.8v but a charger runs at 14.4v, this difference in voltage accounts for the difference in charging capacity.

To answer your question, your leisure battery should be reasonably well charged after a stay on a site with mains hook-up and should run your alarm for a while.

If you keep the caravan at home you can buy, or make up, an adapter so you can plug your caravan mains cable into a domestic socket. Many caravanners, including us, have their caravan permanently hooked up to mains, except when towing of course!

 

[Pete4]

There are many different types of power supplies. If yours is the original unit, it should also charge the battery as well as providing power to the caravan. Normally they provide 14 odd volts as Roger says to the battery and your electrics come from the battery so you get a constant trickle charge to the battery.

Don't leave the van hooked up to the mains for prolonged periods as the battery will overcharge causing sulphur to build up on the battery plates (the annode side I think).

As for running the alarm, if you cannot periodicaly charge the battery, have a look at putting a solar panel somewhere to give the battery a float charge.

 

[trucker]

RogerL says that he leaves his caravan plugged into mains at home as do I, however Pete says not to as it will over charge the battery. Can any one give me the correct answer.

 

[PaulA3]

Leaving the power unit (battery Charger) supplied with a modern caravan on will not harm the battery in fact it will keep it in a better condition than turning it off and letting go flat.

A battery is ruined if it is over charged (gassing) or left discharged as the electrolite ends up sticking to the Plates.

 

[trucker]

Leaving the power unit (battery Charger) supplied with a modern caravan on will not harm the battery in fact it will keep it in a better condition than turning it off and letting go flat.

A battery is ruined if it is over charged (gassing) or left discharged as the electrolite ends up sticking to the Plates.

Thanks Paul

 

[PaulA3]

Pushed wrong key had not finished.

The power unit is desinged not to over charge the battery as the battery nears full charge the unit reduces the charging voltage and just maintains the battery in a nearly fully charged condition.

 

[RogerL]

I've left the caravan battery permanently charging for 22 years without any problem - not the same caravan or battery, though! The present battery is 8 years old and still in good condition.

Permanent connection will work for an "automatic" type of car battery charger or a caravan power supply as neither will overcharge a battery.

Permanent connection WILL overcharge a battery if a cheaper car type charger is used.

 

[DeliDave]

There are powerpacks to start your car in Argos Halfords etc was thinking of one as a backup if van battery goes low,can they be charged by car when driving any other ideas

 

[RogerL]

David - "powerpack...back up...charged by car" - what you need is a second leisure battery, securely fitted in the car boot and charged from the 12S circuitry - this would surely be more cost-effective!

 

[PaulA3]

David instead of a power pack follow this tip I posted in rely to another posting.

This next tip depends on how your 12s plug has been wired

If it has been wired up with a split relay you should have two 12volt supllies that operate only when the engine is running to pins 2 Blue and pin 6 Red cable.

Pin 2 Blue is the Battery charging circuit that charges the caravan battery whilst you travel.

Pin 6 Red operates the fridge whilst you travel ( it only keeps an already cold fridge cold so always either use the mains electric or gas to get it cold before traveling)once you turn the engine off both supplies are disconnected by the relay so the car battery is not flattened by the current drain to fridge and caravan battery.

If you have a split relay then connect to the blue cable in the car the red of a length of twin cable 2.5mm (red and black) connect the black to the car body earth and at the other end connect a polarity socket ( one that will only go in one way so you can not reverse the connection) with a matching plug. Connect another length of the same cable to the plug making sure you keep red to red, black to black. On the end of this connect a crockadile clip to the black, on the red connect an in line 15 amp fuse then a short length of the same cable to a crockadile clip. You will need a second battery and battery box you then connect the crockadile clips to the battery, red to + positive, Black to - negative of the battery. Always have the polarity socket is disconnected when connecting up AND MAKE SURE THE PLUG PINS ARE NOY TOUCHING SOMETHING METAL THAT COULD MAKE THEM SHORT OUT.

This now means that the new spare battery in your boot will be charged up whilst your driving the car so you can swap it with the battery in your caravan when it starts to run down and the run down battery will be charging up whilst your driving.

If your 12s plug is wired so it only has the fridge pin 6 operating when the car is running you will need to connect to the Red wire as above and not the blue wire AND YOU MUST NOT HAVE THE SPARE BATTERY CHARGING WHEN YOUR TRAVELING WITH THE VAN as the fridge and battery current could be to much for the red cable.

If your going to use a 240 volt TV you will need an invert as mentioned earlier However there are some very good flat screen LCD TVs out now that run on 12 volt and 240volts I got one earler this year from Sainsburys its a 15 inch SONIX Unfortunatly for me the have just come down