12v

[paulsutt]

Hi,

Hope this doesn't sound like a daft question!...very new to this!

We have just put our caravan on a seasonal pitch with very limited mains hook up (all are used at the moment)..i've done a bit of research and am i correct in saying that it is possible to buy tvs, sat systems etc that run on 12v supply?

..i realise that these will have limited operation on one battery and how much charge the battery holds etc

Also how would this work?..when switching the caravan to 12v mode does this supply the plugs with 12v?...so you can simply plug in a plug/12v adaptor?

..and last question! to charge the battery what charger would be best?..our Fleetwood Colchester doesnt have a battery meter so at the moment its impossible to tell how much charge it has. Our car hook up is only for the lights so we would have to charge the battery at home via mains.

Any help would be much appreciated.

many thanks

Paul

 

[Damian]

Paul, yes it is possible to buy 12v TV's , sat systems etc, but they are very expensive for what they are and will, as you realise, be limited to length of use by the battery state.

The 12v van system is entirely separate to the mains system, so , when selecting van position for 12v, it will supply the 12v lighting, water pump, fan for blown air heating and 12v outlets.

It will NOT supply the standard 3 pin domestic style socket outlets.

The best charger is a multi stage automatic charger which will bring the battery to its correct voltage and maintain it at that.

On board battery meters are notoriously inaccurate, better to use a multimeter set to 20v DC at the battery terminals.

 

[Parksy]

Hi Paul

I'm fairly certain that a 1990 Fleetwood Colchester will be fitted with a battery charger which should work when you use a 240v electric hook up. There might be a switch to operate the charger, have a look at the switches inside your caravan to find out if there is a car/ caravan switch and to see if there are any other switches.

Most 12v appliances such as tv's need a 240 v supply which then uses a transformer to convert the 240v ac to 12v dc. The three pin sockets in your caravan are 240v which operate via the electric hook up (ehu) and usually 12v sockets are of the round 'car cigarette lighter' type.

If you do need to charge your leisure battery at home a 'smart' charger which features deep cycle /pulse charging is best.

One of the best makes is CTEK and Lidle supermarket also sell a less expensive smart charger sometimes on special offer.

 

[ProfJohnL]

Hello Paul,

Yes it is possible to by many electronic items that will run from 12Vdc, but as you have pointed out the battery in a caravan does have a limited capacity. There is no way you can expect to get full domestic type usage of TV etc relying on only 12V dc.

The 12v dc systems and 230V ac systems must be kept separate, so you need both types of socket where you want to be able to use both mains or 12v. You cannot use the same socket for both.

You say that your caravan does not have a charge meter to show the battey status, I assume the caravan is fitted with a charger, but no indicator. The chargers fitted to caravans since the mid 1990's all comply with a standard. They do not output more than 13.8V dc, which should prevent a caravan battery from being over charged, so in theory it is safe to leave them turned on when a mains supply is available.

There are better chargers available, these sense the charge state of the battery and will adjust their output to suit the demands of the battery. One manufacture is Ctek but there are others, and from time to time Aldi , Lidl & Maypole have similar products at substantial savings. But in both cases, the one fitted by the caravan manufacture and the other models require mains power to recharge the battery.

You can get relatively cheap volt meter displays that can be fitted to the caravan to show the terminal voltage of the battery. This will give you an indication of the remaining capacity of the battery. A good caravan dealer should have one. Alternatively a slightly more complex one is available from Towsure see:

http://www.towsure.com/product/17075-Battery_and_Alternator_LED_Tester
It worth noting that any meter you use is likely to use some power and if left connected for long enough will deplete the charge in the battery.

You can get low power LED bulbs to replace conventional filament lamps. This can make a big difference to the power you use.

I hope this helps

 

[paulsutt]

..thanks everyone for the advice..makes sense now!

i don't want to run before i can walk but i'm fairly sure (can't check caravan today) that we only have approx 3 240 sockets in the van. I can't remember seeing any 12v cig type sockets at all.

..we do know a very good electrician..i was just wondering in the future if we did want to add some of these 12v sockets how difficult is it?

many thanks

Paul