Replacing the batteries is a simple operation that does not affect the warranty in any way.
You will need a small flathead screwdriver and the batteries used are 2 AA alkaline batteries , a type that can also be easily found in the supermarket.
Here are the steps to follow:
1. Turn the device over.
2. Insert the screwdriver into the groove next to the button.
3. Turn the screwdriver clockwise, being careful not to break the teeth on the back cover
4. Remove the batteries
5. Insert the new batteries, orienting the positive (+) and negative (-) ends as indicated on the labels inside the compartment.
6. Perform a connection and/or opening test with the case still open
7. If the test is successful, close the lid by aligning the teeth near the grooves.
Here is a demo video of how to open SOLO AUTO: https://youtube.com/shorts/4Kh_Rq-7TNo?feature=share