on 16/01/2014, sionbach supposed :
> Hi everyone, been searching internet for a week or so now trying to
> install a battery in a hobby 720 2002 european version. Ive also phoned
> a few places but once I tell them I have a hobby the mood changes and
> most becomes unhelpfull.
I've been rather too busy to give this much time, but here goes...
First, I am still not entirely convinced that your existing 12v supply,
is AC, because you mention installed appliances which so far as I know
only come in 12v DC versions. There just would be no point in
installing 12v AC at all. You mentioned a Truma fan, a car type radio
and I assume a 12v water pump. Feed such a radio AC and it will self
destruct. Rather I think your problem with the radio is lack of current
or voltage (drop).
Now assuming it is DC, you would need to install a modern 13.8v 15 or
20amp charger /power supply, a battery and a suitable 12v fuse panel,
pick up the existing wires for your existing 12v equipment and maybe
more. When on mains, everything would automatically work on the PSU,
but when off mains it would run on battery.
Installing such would be quite an involved job, so it would be
pointless attempting it with any expertise.