I Have just picked up my new pendleton somerby e bike from Halfords and had a 3 hour bike ride. Love it so far but confused as it seems that you cannot lock the battery in if you were to leave the bike chained up outside while you pop into a shop, am I doing something wrong as it seems the key stays in the lock to lock the battery in place but it means someone can turn and take the key and remove the battery, any advice welcomed .