Solved! Surface Pen wont connect

[Uhidk]

So I replaced my battery with one from a few months ago, I remember putting the + side outside
My pen is the 2017 version
When I pressed the eraser for 7 seconds it didn't light up and it didn't show up in the list of devices
(It's a surface pro 5)
What do I do?

 

[Saga Lout]

If you didn't charge that battery from "a few months ago", it will need as much as an hour on mains and the device.

 

[mrmike16]

So I replaced my battery with one from a few months ago, I remember putting the + side outside
My pen is the 2017 version
When I pressed the eraser for 7 seconds it didn't light up and it didn't show up in the list of devices
(It's a surface pro 5)
What do I do?

The + side is supposed to go towards the tip of the Surface Pen, if I am remembering it right.
If the light isn't coming on after holding down the top button for 7 seconds, then there's no power. Check that the battery does have a charge and that it has been inserted properly.