Leisure batteries

[Mark_374475462]

I have recently returned to caravaning and the van I now have seems to me to be reliant on the 12 v battery even though it has full 240 volt supply.

The van relies on the 12v volt supply for most of the lights, the water pump, the fan heater blower and the electric water heater as well as the gas ignition systems on the fridge and cooker hob and the gas water heater.

My question is this normal and how long can I expect a new 80amp hour battery fully charged last without with normal use before recharge...........I am running single plug electrics from the tow car however I am happy to hard wire a battery charger if needed

 

[James_374408700]

Mark,

Do you intend to use non EHU sites and will therefore have to rely on the 12v battery alone.

Or if on 240v supply then presumably the van has a charger/transformer to supply the 12v needs ?

Jim

 

[WatsonJohnG]

If you watch colour Tv about 3 days max

 

[ProfJohnL]

Hello Mark,

Most touring caravans are still designed with the concept that it should be able to be used without mains power being available, hence the items that run on 12V dc. It is very common these days to find most caravan sites offer some or all pitches with a 230V mains supply, so some caravans are now being designed with no 12V habitation systems. At the moment these are mainly continental designs, where it is quite common for a caravan to be sited in one place for a whole season.

I will assume for a while that you r caravan is British, and built some time after 1980, and thus I am surprised your caravan does not have a mains charger or power supply already built in.

These were often part of the power switching panel. Perhapse you do have one but it is faulty or a fuse may have blown, a little investigation should reveal the answer.

However back to your question, It a bit like how long is piece of string ? Ultimatly the battery will have only so much charge, even though it classed as an 80Ah, it is unlikely to hold that amount due to the way it was charged and its age. In theory a fully charged 80Ah battery should be capable of provide is constant current of 1 amp for 80 hours, or conversely 80A for 1 Hour. In practice the formwer is more likely than the latter for a number of reasons.

If you know or can find out the current rating of each of the appliances you have, then by Woking out how long each appliance is used for each day (amps per day) then dividing that figure into the capacity of the battery will roughly give you your battery life.

Purely as a rough guide, most florescent lamps consume about 1.5A per hour, Filament bulbs about 1A per hour, The water pump is probably rated at 6A but it only runs for short periods so it daily usage is only likely to be about 10 mins total so that is 6A or 1Ah. Heating fan 1.5A, water heater control 0.5A.

The biggest consumers are usually lights and fans which are on for long periods, or high powered items like 12V TV's.

Used carefully many people will easily survive a weekend on an 85Ah battery, but its all down to how much you use the appliances.

 

[Martin24]

We have a 110 battery which easily used to last the weekend on the rallyfield including motor moving off and onto our gravel drive each end of the weekend, however we now have a solar panel to keep things charged up as we now never go to sites with electrics (unless have CC vouchers to use up, and even then we forget the kettle, and once even the mains lead!)