Banner makes sense, we want to come up with a solution there.
Bu the EC querying should fail, no? As in, sweetberry shouldn't have a battery command, or even an ec_pty, so that PowerTracker shouldn't get initialized. Does it?

I'm more thinking along the lines of querying servod to determine what servo device is currently in use. If it's Sweetberry then there's no need to add the EC Power tracker, since it doesn't exist. 

Users who know that Sweetberry does not provide EC data won't care, but users who don't know that would not be surprised by an error message. 

Makes sense. (This comment is just to keep track of a thought)
Maybe it makes sense to query if the device has ec_pty & if it doesn't, then assume it's a servo device that doesn't support ec querying. That way we don't have to hard-code a servo type etc.

This is addressed in crrev.com/c/1400384