Benrus battery change

I got this watch some time ago and I believe this is its first battery change. That is pretty long, but then based on the information in the Ronda website, based on the movement used, battery life is about 4 years. 

The movement in the watch is the Ronda Powertech 513. 

Photograph: Ronda

The Ronda Powertech 513.

Anyway on to the battery change. 

The watch. It is a 'Benrus Type 1' watch or a modern take on the watch. I am not even sure if the watch is made by Benrus. 

Remove the NATO strap.

The first problem I face is the removal of the case back. I do not have the correct tool to remove the case back as the slots are round and not the normal slots you see on most watch case back.

The tool that I have...

A closer view shows that it not the appropriate tool for the round slots. There are a couple of ways around the problem. You could always bring the watch to the shop and hope they have the correct tool or you could buy the correct tool. 

The other way is to get one of these, a friction ball.

Photographs: Amazon

And there is the non official way to get around the problem. You could use cellophane tape and tape over the slots or use this...

My secret tool.... a simple ziplock bag. 

And this is how you would use it. Be aware, this does not guarantee that you would not damage the round slots. 

The case back removed. 

The inside of the watch. Remove the spacer/ battery holder and change the battery. Check that the watch works before closing up. Also remember to clean the inside of the watch and lubricate the seals. 

And we are all done.