1 week away on just the battery.

[Neil_374351942]

Were heading off for a week and will just be on battery power (85A new battery)- we just have the odd light on in the evening, the blow heater on if its coldish and a quick shower once a day.

Will my battery last me a week?

Also, could we use a 'slow cooker' without affecting the battery too much?

 

[Reg]

You can work it out for yourself really.

An 85A battery is really 85Amphours i.e. if you draw 8.5amps it will last for 10 hours....... in theory!

So total up the current drawn by each device (amps) then divide that into 85 and this will give you the amount of time your battery should last........ in theory!

In practice I would half it. The problem is that a battery will only deliver its max output for a limited time and then begin to drop off. Although leisure batteries are designed to give a more constant supply as opposed to car batteries which are designed for high surges.

My gut feeling is no it wouldn't last.

 

[PaulAsserati]

Is it not possible to hook it up to your running car for a while when the battery gets low??

I know its not the most enviromently friendly way of charging a caravan battery but it must do the job.

 

[Dave_374330759]

As Reg says, do the sums. A 10 watt light will take about an amp. The heater blower will take about 1 amp on full speed (but do you need to use the blower anyway) The gas valve in the hot water heater (Truma) is an average of 0.1A = about 2amps/day and the water pump will be 4-5 amps but only for the period that it runs, say 20mins total a day = 1.5 to 2 amps/day. So working on the above 2amps for hot water, 2 amps for the water pump and say 3 amps for lighting = about 7 amps per day if you are frugal. I personally would not flatten the battery (you will drastically shorten its life) so taking it down to 50% charge will give you an available 40-45 a/h divided by 7 a/h = about six days without killing the battery. Change some of the lights for LEDs and you could save even more.

 

[Rod_5041370]

Neil,

Do you mean that you have a 12 volt slow cooker?

 

[JeremyClarksson]

Definitely forget any 12V or mains via inverter heat appliances.

I would not expect to get a week out of an 85AH battery, I would get an extra battery to recharge when out in the car or with the site owner, or look at solar panels and generators.

 

[alaintaylor]

Neil

I would say 'yes', if you are careful. I've managed 10 days in the past but only by sharing the time with the car grey connection (by using an extension cable). However, you can only use the car battery if the car itself is being driven fairly regularly to recharge its battery. In the good ol' days my caravan didn't have a leisure battery and the lighting ran off the car every night with no problems but then we had no other electrical equipment! By being careful definitely means no slow cooker or any other devise that pulls a lot of power (any heating element, TVs, etc). When you leave the van turn the master switch off to conserve power but check first that by doing so doesn't turn the gas fridge off (many fridges need 12v power even to run on gas).

Alan

 

[Neil_374351942]

Many thanks for the replies - its helped a lot.

All the best, Neil