Liesure Battery Charging during winter

Dawn F

Hi We are new to motorhoming, got our first motorhome 4 weeks ago, we have put it in storage over winter.  When we left it 3 weeks ago we ensured everything was switched off.  We have been today to check on the batteries, the van started first time no problem. 
We have taken it on a motorway drive approx 70 miles in all, the display is saying the leisure batteries have no charge?  Also the radio & reversing camera will not work, is this connected and is it normal for the batteries to get low after just 3 weeks?