EM50 LED - should it be on?

I was in the van today getting it ready for the season and noticed, for the first time, that the red led in the EM50 behind the driver's seat was on.
Is this normally on with the control panel switched off? If so, might this be part of battery discharge problems in storage?

My EM50 is hidden behind a storage bag - juts been to look and its on all the time as well. I've e-mailed Sargent and asked the significance.

Thanks for checking, Peter - and for emailing Sargent.  An insignificant current - but over several weeks - mmm! Presumably that will be a drain on vehicle battery - or might it be habitation?  I will have to investigate when I have a moment.

Mine is always on. Seem to take its feed from the vehicle battery. No means of disconnection.

The reply from Sargent says the light indicates the unit is getting power. I haven't got time to test which battery its fed from but with my solar panel, its not a problem.