Why longer Lock Mortise is not a good idea

There are many many model hotel locks in the world.
Some models hotel lock put the battery case under the lock mortise.
They use a long lock mortise.

Just like this

For customer it is not good

my opinion this is not a good idea.

I once heard a customer from South Africa say that he didn’t like this style.  Because this will cause extra work 
I think why this design comes out on original purpose of simplify the locks design.

However it also cause many issues.

1. Oil
   

The lubricating oil of the machinery inside the lock body, sometimes not solid, will flow down.The battery case is right under it.

Drill a extra longer groove on door.
To put in such a longer lock mortise, the groove on the door also must be much more longer than usual mortise.
This is a extra work should be done by some workers, when installation the hotel lock. And also it brings extra cost on drilling.

Doors can not goes back to change another usual size mortise.
The most important thing after drilling such a special size pocket is,your doors can NOT exist without such a longger mortise. That is to say, you can not install a usual and normal size lock mortise on door.

For manufacturer, it is good

Actually the longer lock mortise’s major benifits is that the style of hotel door lock could be very simple.

Simplified hotel door lock’s design.  Manufacturer could save energy and time about how puting the battery case on the lock panel. They like it very much.

1. The door lock can be very simple panel.But did it add any real value?
   

Longer hotel lock mortise not brings more convenient.

When you see the battery under the mortise, you may think that is a innovation. And maybe it brings more convenient when replace battery.

But unfortunately, it won’t give more convenient.

It is even more troublesome to change the battery than a regular door lock.
You could see follows compare, with conventional hotel lock battery back.