one year ago I purchased a motorhome and have only just found that it has a Cobra 3865alarm fitted, I do not have a fob of any kind, after taking it for its MOT, the alarm started to beep when the doors were open, it stopped when closed, no problem, but after a few days left in the drive the battery was fully discharged, I disconnected and charged the battery, starts OK. What can/should I do now?, many thanks, Alan ??