batterys

Not sure but ask Naomi, she managed to boil our EHU's

I think what should be posted here is the awful smell the boiling batteries created (I was with Dave when it happened) so that other members know what to look out for.

Rotten Eggs with a bit of a burning sensation on the back of the throat! the smell was incredible, but was very like a smelly waste tank and easily mistaken for that.

This could of proved dangerous as the battery is producing hyrdogen Gas as it was boiling and if ignited could explode.

i will look into that robbie if ur right new battery will have same problem although van ( starter ) battery is ok thanks

Self discharge on your battery
The down side of lead acid batteries is that they discharge all by themselves even if not used ie not connected at all. A general rule of thumb is a one percent per day rate of self-discharge on a new battery. This rate increases at high temperatures and decreases at cold temperatures also age. Don't forget that your Motorhome/Camper, with a clock, stereo, and radio and ECU (main battery) is never completely turned off. Each of those devices has a "keep alive memory" to preserve your radio pre-sets and time, and those memories draw about 20 milliamps, or .020 amps. This will suck about one half amp hour from your battery daily at 26 degrees Celcuis. This draw, combined with the self-discharge rate, will have your battery 50 percent discharged in two weeks if the camper is left unattended, The same applies to your leisure batteries and moreso the newer the camper as the likes of the sergent units monitor all the time also webasto systems have a constant monitor on the batteries themselves. So without being to techie every couple weeks a hook up is handy, Solar will help as will a drive or starting up and running but none of these are as good as just hooking into a supply for 24 hours.
hope this is of some help been near 3 decades from I done me uni in electro mech engineering lol

I was led to believe that newer vans are ok to leave on EHU all the time as they top up the battery when required, whereas some of the older vans the chargers carry on charging.

Not sure what year this was supposed to change though.

I would Keep an eye on your battery state of charge and just run an extension lead into the van for the heater rather than keeping the controller unit ie the Sargent unit powered up, most of the modern controllers incorporate a float charger system rather than a continious charge which used to be used and over time damaged the batteries.
A voltage of 12.6V at room temperature gives a good indication of around 90% charge, dropping the battery below this the battery needs to be charged to prevent sulfation.
If your charger stays on topping charge and does not drop below 13.8V, remove the charge after 48 hours of charge as the motorhome most likely does not have a float charger.

We have a small 500mm 55w slimline heater in our van which has inbuilt overload protection and a thermostat, Using a couple of dry bags its amazing how much drier the air is inside the van with a very small manipulation in internal temperature.