Leisure battery advice

[alex_374294702]

I am new to caravanning having just upgraded from trailer tent to a Rapido Pop Top. I need to buy a leisure battery but am confused as to which I need the amps given vary from 75 - 85 - 95 -110amps. I intend running fridge and internal lights, possibly TV if my child gets her own way. I have generator left over from trailer tent which I assume and correct me if I am wrong will replenish the battery's charge as and when.

Help and advice would be appreciated.

 

[rob_jax]

Hi,

We have an Eriba Triton pop-top and hope you enjoy your new caravan.

A couple of things - a normal 3-way fridge will draw more than 10 amps and will totally flatten a 110 AH battery in 11 hours - and that ignores any issues about not draining a leisure battery totally.

Eriba owners who enjoy "wild camping" in Europe run their fridge on gas, and use 12 V for pumps, radio and lighting in the evening. The friendly way to recharge the leisure battery is a 44 Watt (or bigger) solar panel, but a generator used for a few hours shouldn't hurt - especially if everyone else is away.

Our Eriba Triton has an 85 AH battery, a Reich motor mover, and a 40 watt panel - this is good for a few weeks away.

Robert

 

[ProfJohnL]

Hello Alex,

Rob_jax has given the basic information, but I would like to add that the fridge will be vastly more fuel efficient if run on Gas. With the best will in the world a small generator is only about 7% efficient at converting fuel to useable electricity, where as the gas power has to be in excess of 70% efficient before it can be legally sold.

The battery rating gives an indication of how much power can be supplied before it is discharged fully, and it works like this:

If you had a fully charged 85Ah battery, in theory you could draw 1 amp continuously for 85 hours. If your current was 2A, then the battery would last only 42.5Hours, 4A for 21 Hrs etc.

You actual current draw depends on what appliances are running at any one time. By adding up the combined current ratings of the appliances you would get the total current draw, but of course you don't have everything running together all the time.

If you can estimate the running time of each appliance (in hours) for each day, and multiply that by the current draw for the appliance you can calculate the Ah for that appliance, so for example:

A water pump may only run a total 20min in any day, That is 1/3 of an hour. It draws 6A, so 6x1/3 = 2 Ah per day.

Similarly each 12V light may be on for 3Hours each day and draw 1.5A so 1.5x3 = 4.5Ah per day

A TV may be rated at 48Watts which is 4A at 12 V. so 3 hours of TV will use 4 x 3 = 12Ah per day

Do the same for each of your appliances and by adding together all the results you will get an estimate of the amount of power you use each day. Divide you battery rating by this figure to estimate the number of days a battery would last.

Any additional charge you can put into the battery will extend the time the battery will last.

Do be warned though, Most caravan chargers do not full recharge the battery, and as a battery ages, its capacity will decrease.

Incidentally exactly the same approach can be used for mains powered appliances, though the currents will be much smaller.

This can be an interesting exercise and it can open some people's eyes to the wastefulness and cost of not turning appliances off.

 

[alex_374294702]

May I thank you so far foor your assistance, you have certainly clarified a few issues for me.

I know I may sound like a dizzy blonde but does using generator or solar panel (which i had not thought of until your post) actually recharge the leisure battery itself. You can well tell I have only been used to basic tenting can't you, I have never had the luxury of a fridge and lights before!!

I will be using the caravan at agricultural shows throughout the summer and very rarely would have electric hook up hence all my questions.

If I look to buy solar panel should I look for any particulay type etc???

 

[popupJohn]

Woooooooooooopeeeeeeeeeeeee another popup owner joined )

Welcome to the forum.

We use a 85AH battery that seeme so give us what we want but everybody will have differing needs. Ours is usually only used for lights and water pump