> Is the van parked anywhere near a Mains outlet such that you
> could employ a small battery charger? After being fully charged
> (during a highway run), the battery should be kept at roughly 13.5V
> while idle. This is called a "float charge" where no actual
> charging is going on but just enough voltage is present to
> counteract the tendency to discharge.
>
> Caution: Don't use a "trickle charger" as these can over-charge
> the battery over a long time.
>
> (It's also possible that there is some load from an accessory
> discharging it or that the battery is reaching end of life.)

Nope - it's in a garage down near the airport without access to mains
of any kind I don't think there is anything connected to the
starter that discharges it, I have a leisure battery that powers
everything else seperately. It is probably an old battery. Once I
can get it turned over I'll shoot to the nearest autoshop and get
something bigger with a larger CCA for the winter months.