Autosleeper Gloucester/Malvern

Mine is a bespoke plastic battery box with a lid and a tie down strap (something like https://www.ebay.co.uk/itm/NOCO-Universal-Plastic-Battery-Box-Group-24-27-31-Boat-RV-Marine-Trailer-Snap-/261893152311 ).  

It was in the middle of the locker at the back but when I removed the bed mechanism I moved the battery box to the back right out of the way.  It is not vented.  

Both that and the battery under the front passenger seat are connected in parallel, the connection being at the base of the EC325.  That means that if the battery fuse of either the front or back battery fails, you still have a leisure battery but of only half capacity.  So a couple of times a year I take out the fuse for each battery in turn and check I still have a LB voltage on the Sargent (having disconnected (or covered) solar panel).

For the cost of a new box, I would replace mine if it was in the same condition as yours and have the battery checked.  The battery I currently have there is:

That's where mine was before I moved it.

gemdeco wrote:I thought batteries gave off explosive gas while being charged and therefor should be vented when in a confined space
Alan

When they come fully charged, they start to gas but the charger in the EC325 turns itself down when it gets to that point.  As the EC325 battery/charger is disconnected from any load it could get to the point of gassing after a week or two which is why I recommend switching the charger off for a day every week when you are on site.

I've survived 6.5 years with this configuration so I'm sure you will be ok.

I worked for a few years with a chap who had been the battery specialist for AT&T (major US comms company), they did some tests and found that (unless the battery was in a very confined space that actually trapped the gas) you had to get a flame into the cell itself to set off the explosion.  This was actually reported a few years ago on this forum.  A member was having some welding done underneath the van, the welder did not appreciate the significance of the battery vent pipe appearing through the floor and offer the flame to it, it shot up the pipe, into the battery which duly exploded making a right mess in the van - in this case he would have been better off without the vent tube.