Google map APi has free quota, 200$. This is more than need for 1 site.
To create your application's Google map API key:
1. Go to the API Console. console.developers.google.com/
2. From the projects list, select a project or create a new one.
If the APIs & services page isn't already open, open the left side menu and select APIs & services.
3. On the left, choose Credentials. There Please add all your sites names with "http", "https", "www",
4. Click Create credentials and then select API key.
You need update Key in admin->Extensions->Modules->Location Map-> "Google map key"
Or please check:
P.S. Please do site backup 2 times per month