Wild camping in winter

Hi,
Leading up to New Year we planned to stay near relatives in our Fairford on a lay-by in Yorkshire, which meant running off the battery and gas for a few days.
However, after the first night, the battery was too low to last another one.
I think the leisure battery was probably draining too quickly with the heater fan on (although only on Eco setting). We had to keep the heater going as there was snow about.
We had to move to a site where we could hook-up for the remainder of our stay.
Can anyone think of any other reason for the battery draining, or do you think the fan was enough?
Thanks.

On the face of it, that does seem poor in terms of battery life.

However, there are factors we don't know. Firstly, was the battery fully charged before you got to site? The split charge circuit that A/S use to charge the leisure battery while the engine is running is fairly limited (typically they use a relatively thin gauge wire over a fairly long distance) which means that it can take a long, long time to recharge a part-discharged battery just by driving.

Then there is the question of what state the battery is in. It's well known that, for example, vans that have sat at a dealers for a while may have leisure batteries that are in very poor condition - prospective customers may leave 12V appliances turned on, and dealers often don't bother to recharge the batteries on their stock regularly.

And then there is the question of what ~total~ load you were placing on the batteries. We've had an example recently of someone leaving the (optional) tank heaters on when off EHU, and that will kill the leisure batteries pretty quickly. The control panel on your van should give an indication of the total current being taken from the leisure battery (though in many cases you will need to recalibrate this to get an accurate reading).

Thanks mojo,
Could be a good point on the state of the battery. The motorhome had been standing a while before this run - I hoped 200+ miles would have been enough to charge up, but you may be right.
I will also need to read up on the control panel as I am not sure what the displays are telling me!

My idea of wild camping any part of the year is EHU on a nice site

As was mine before trying this trip!

I wild camp frequently in my Trophy and agree EHU is best, but although I have once run out of propane on a freezing night in Welsh Mountains (don't try it) I have never run out of leisure battery.

A few tips on battery care:

Mine was in low state of charge but not bad condition when I got it. In this condition they are very slow to fully charge and I ended up leaving it on the hookup charger for about three days. After that it was OK but not perfect.
After a few partial discharges and recharges I think it is as good as new.

I give it an extra charge with an external charger occasionally which takes it up to  14.4 volts instead of 13.8 but I don't think that pushes much more into it.

With the battery now in good condition, it recharges fairly quickly to say 80% when driving, but it does take a long time to get it really full, say a four-hour drive.

The heater only takes a couple of amps, so 8 hours continuous use is maybe a quarter of the battery capacity, but on a sensible temperature this reduces by half.  If I turn the thermostat to minimum, it keeps the Trophy at 7C which is OK for while in sleeping bag, and consumes very little gas or battery. That is, with toilet door closed and with the cab separated of with a fairly thick curtain.

Of course lights etc take a fair bit more, so I use tehm as economically as possible.

I guess half an hour drive each day will keep the battery up enough for a week, when I usually get back to hook up and so on,,,

When not in daily use I charge on hookup for a few hours and/or by driving 20+ miles each week, and so far so good.

Hope this helps