How long with the Battery last??

[glenno]

Has anyone calculated how long their leisure battery should last and compared this result to actual?
I’m going on a site with no electric for the first time so I did some sums :-

There for 5 nights next month (July), and assuming :-

22” TV @ 2 hrs per night 45watts or 3.8amps = 38AH
Led lights (5 off at 2hrs per night @ 2W each = 12AH
Water pump @ 20mins per night assuming 3amp = 5AH
Water Heater on Gas continuous uses 0.02A or 3AH
Cant find specs for fridge so assume same as water heater = 3AH

So that’s a total of 60AH.

My battery is 85AH. But lets say its only 75% efficient. So that’s 64AH

So I should just about do the trip before the battery is flat????

 

[Woodentop]

Has anyone calculated how long their leisure battery should last and compared this result to actual?
I’m going on a site with no electric for the first time so I did some sums :-

There for 5 nights next month (July), and assuming :-

22” TV @ 2 hrs per night 45watts or 3.8amps = 38AH
Led lights (5 off at 2hrs per night @ 2W each = 12AH
Water pump @ 20mins per night assuming 3amp = 5AH
Water Heater on Gas continuous uses 0.02A or 3AH
Cant find specs for fridge so assume same as water heater = 3AH

So that’s a total of 60AH.

My battery is 85AH. But lets say its only 75% efficient. So that’s 64AH

So I should just about do the trip before the battery is flat????

Slight error there.

5 lamps @ 2W for 2hrs per night = 5x2x2=20Wh or about 1.8AH

 

[WoodlandsCamper]

The following also may use power from the battery:
TV aerial amplifier
Fridge control panel
Toilet flush
Radio

 

[KeefySher]

Do you want to borrow a generator to top up the battery?? Use infrequently

 

[Dustydog]

https://planetcalc.com/2283/
Glenno
See the above link.
The battery may not last as long as you thought. Also remember the older and more cycles a battery has undergone the less it will perform. Maybe take a spare as a back up.

 

[Tukums]

Never worries me, 12 nights so far and the 110amp battery is always charged by lunchtime or afternoon if cloudy even using 12v TV 4hrs a night. Solar is the way to go off grid. (Mine is a 150w panel)

 

[Martin24]

If you're going to regularly away from ehu, I would suggest going for a 110 battery and a free standing solar panel of at least 50w or roof mounted of at least 100w. That way you won't have any problems. As it is your current set up, imho, won't last you five nights.

 

[ProfJohnL]

Has anyone calculated how long their leisure battery should last and compared this result to actual?
I’m going on a site with no electric for the first time so I did some sums :-

There for 5 nights next month (July), and assuming :-

22” TV @ 2 hrs per night 45watts or 3.8amps = 38AH
Led lights (5 off at 2hrs per night @ 2W each = 12AH
Water pump @ 20mins per night assuming 3amp = 5AH
Water Heater on Gas continuous uses 0.02A or 3AH
Cant find specs for fridge so assume same as water heater = 3AH

So that’s a total of 60AH.

My battery is 85AH. But lets say its only 75% efficient. So that’s 64AH

So I should just about do the trip before the battery is flat????

You have done you calcs, and with woodentop's correction, and Woodlands addition thoughts (although you had already considered the fridge)

Whilst I think you would just make it based on your assumptions, for that little bit of added security Martins suggestion of a 110Ah battery does seem logical. Or rather than spend on a new battery, invest in a solar panel. - even 20W one would help to offset some of the power the usage.

You could accidentally forget to take the aerial , so teh telly wont work, and then youd be fine for a fortnight

 

[glenno]

Thanks for the replies. Like i say we normally use sites with ehu so not worth investing in solar panels. This trip is the F1 at Silverstone so it's a one off. Ive another car battery in the garage so i will take that with me just in case.