You can't use google maps at all without a business account if the maps (and content) aren't 'publicly available'. If you're using their maps for internal apps

You can't use google maps at all without a business account if the maps (and content) aren't 'publicly available'. If you're using their maps for internal apps or you charge for access to your app, you have to use a business account. Business accounts start at $10k a year and scale up from there depending on usage and other factors.